Exhibit 10.34



                       ASSIGNMENT AND ASSUMPTION OF LEASES
                       -----------------------------------


             THIS ASSIGNMENT AND ASSUMPTION OF LEASES  ("Assignment") is entered
into as of the 12th day of  November,  1996,  by and between  CEPHALON  PROPERTY
MANAGEMENT,  INC.,  a  Delaware  corporation  ("Assignor")  and  NORTH  AMERICAN
VACCINE,   INC.,  a  Canadian  corporation   ("Assignee").   For  good  valuable
consideration,  the receipt and sufficiency of which is hereby acknowledged, the
parties covenant and agree as follows:

             1. ASSIGNMENT.  Assignor hereby  assigns,  transfers and sets over
unto Assignee,  and Assignee hereby accepts,  all of Assignor's right, title and
interest in and to (i) that certain  Lease dated  December 28, 1990 and Addendum
thereto,  (ii) that certain Lease dated  November 12, 1991 and Addendum  thereto
and (iii) that certain Lease dated March 20, 1992 and Addendum thereto,  each as
amended by that certain  Amendment to Leases dated November 12, 1992 and by that
certain letter dated December 29, 1992,  copies of which are attached hereto as,
respectively,  Exhibits "A"-"E" and made a part hereof (collectively as amended,
"Leases"),  each between TR Muirkirk  Corp.,  successor-in-interest  to Muirkirk
Manor Associates Limited Partnership, as landlord, and Assignor, assignee of Bio
Science  Contract  Production  Corp., as tenant,  which Leases pertain to Suites
260, 270, 280 and 290, 9000 Virginia Manor Road, Park Place, Beltsville,  Prince
George's County,  Maryland ("Premises").  This Assignment includes an assignment
to Assignee of all rights in and to all security deposits paid by Assignor under
the Leases, all allowances and amounts available for lessee  improvements to the
Premises,  and all refunds of rent or additional rent paid by Assignor under the
Leases.

             2. REPRESENTATIONS AND WARRANTIES. Assignor represents and warrants
to  Assignee  that:  (a)  Assignor  is the tenant  under the Leases and the sole
occupant  of the  Premises,  (b) the  Leases are the only  leases or  agreements
whereby any person has been  granted the right to use or occupy the  Premises or
any part thereof,  (c) Assignor has not previously assigned the Leases or sublet
the Premises and has received no notice of a prior assignment,  hypothecation or
pledge of the Leases or the rent payable thereunder, (d) there exists no default
by Assignor or to Assignor's knowledge,  the landlord, under the Leases, and, to
the best of Assignor's knowledge, no event, fact or circumstance which, with the
giving of notice or the passage of time,  or both,  would  constitute  a default
thereunder,  (e) the  security  deposits  due under the Leases have been paid in
full,  the amount of the security  deposits  has not been reduced to  Assignor's
knowledge,  and  Assignor's  interest  in the  security  deposits  has not  been
previously  pledged,  assigned or otherwise  transferred,  (f) the copies of the
Leases which are attached  hereto are true,  correct and complete and constitute
the entire  agreement  between  Assignor and the landlord under the Leases,  (g)
there are no actions or proceedings,  whether voluntary or involuntary,  pending
with respect to Assignor under any  bankruptcy,  insolvency,  debt adjustment or
similar  law of the  United  States  or any  state  thereof,  (h) to  Assignor's
knowledge,   the   landlord   under  the  Leases  has   fulfilled   all  of  its
representations,  warranties  and  agreements  under  the  Leases,  and  (i) the
construction and installation of all "lessee  improvements" to the Premises have




<PAGE>



been  completed  in all  respects in  accordance  with the Leases,  there are no
payments due the landlord  under the Leases or any other party from  Assignor or
due Assignor  from the  landlord  under the Leases in  connection  with any such
work, and the amount of $0.00 remains available for use in completing such work.

             3. PERFORMANCE.  Assignor shall be responsible  for the observance
and  performance  of all  agreements  and  obligations of the "Lessee" under the
Leases arising prior to the Effective Date (defined  below).  Assignee,  and not
Assignor,  shall  be  responsible  for the  observance  and  performance  of all
agreements and  obligations of the "Lessee" under the Leases arising on or after
the Effective Date.

             4. EFFECTIVE  DATE.   Notwithstanding  anything  to  the  contrary
contained  herein,  this Assignment  shall not become  effective until such date
("Effective Date"), if ever, that Assignor and Assignee (i) enter into an Assets
Purchase  Agreement  providing for  Assignee's  acquisition of certain assets of
Assignor   located  on  the  Premises  and  (ii)  consummate  the   transactions
contemplated thereunder.

             5. INDEMNITIES.  Assignor shall defend, protect, indemnify and save
harmless  Assignee  from and against any and all  liabilities,  suits,  actions,
losses, damages, costs and expenses, including, without limitation, counsel fees
and court costs,  suffered or incurred by Assignee resulting from or relating to
any  failure  by  Assignor  to  observe  or  perform  any of its  agreements  or
obligations under the Leases prior to the Effective Date. Assignee shall defend,
protect,  indemnify  and save  harmless  Assignor and  Cephalon,  Inc.  from and
against any and all liabilities,  suits,  actions,  losses,  damages,  costs and
expenses, including, without limitation,  counsel fees and court costs, suffered
or  incurred by Assignor or  Cephalon,  Inc.  resulting  from or relating to any
failure by Assignee to observe or perform any of its  agreements or  obligations
under the Leases accruing at or after the Effective Date.

             6. BINDING EFFECT; SUCCESSORS AND ASSIGNS. This Assignment shall be
binding  upon and  inure to the  benefit  of  Assignor  and  Assignee  and their
respective successors and assigns.

             7. FURTHER ASSURANCES. At Assignee's request, Assignor will execute
and deliver such documents and instruments and take such other actions as may be
requested reasonably from time to time by Assignee as necessary,  appropriate or
desirable  to carry out,  evidence  and  confirm the  intended  purposes of this
Assignment.

             8. GOVERNING  LAW.  This  Assignment  shall  be  governed  by  and
interpreted  and enforced in accordance  with the laws of the State of Maryland,
without giving effect to conflicts or laws principles.



                                      - 2 -


<PAGE>




             IN WITNESS  WHEREOF,  Assignor  and  Assignee  have  executed  this
Assignment as of the date first above written.


ATTEST:                              CEPHALON PROPERTY MANAGEMENT, INC.


/s/ Barbara S. Schilberg             By:/s/ J. Kevin Buchi
--------------------------              ---------------------  
Name: Barbara S. Schilberg              Name: J. Kevin Buchi
      --------------------                    ---------------  
Title: Assistant Secretary              Title: Vice President
       -------------------                    ---------------

(Corporate Seal)

ATTEST:                              NORTH AMERICAN VACCINE, INC.


/s/ Russell P. Wilson                By:/s/ Daniel J. Abdun-Nabi
---------------------                   ------------------------
Name: Russell P. Wilson                 Name: Daniel J. Abdun-Nabi
      ---------------------                   --------------------
Title: Assistant Secretary              Title: Senior Vice President 
       -------------------                     - Legal Affairs
                                               ---------------------


(Corporate Seal)



                                      - 3 -


<PAGE>


                                   EXHIBIT "A"

                                   FIRST LEASE
                                   -----------

                                      LEASE
                                      -----

                                   (PARK PLACE)

         THIS LEASE, made as of this 28th day of December,  1990, by and between
MUIRKIRK MANOR ASSOCIATES LIMITED  PARTNERSHIP,  a Maryland Limited  partnership
("Lessor"),  and BIO SCIENCE CONTRACT PRODUCTION CORP., a Maryland  corporation,
("Lessee").


                              W I T N E S S E T H:
                              -------------------

         That in  consideration  of the rent and mutual covenants and agreements
contained  herein,  and intending to be legally bound hereby,  Lessor and Lessee
agree as follows:

         1.   DEMISED PREMISES
              ----------------

              The  Lessor  leases  to the  Lessee  all  of  that  certain  space
described as Suite No. 290, 9000 Virginia Manor Road,  containing  approximately
14,200  square feet of gross  leasable  area,  as is outlined in red on the plat
attached  to and  made a  part  of  this  Lease  as  Exhibit  "A"  (the  "Leased
Premises"),  and located in Park Place, Prince George's County, Maryland. Lessor
shall  construct and complete the Leased  Premises in compliance  with the plans
and  specifications  set forth in  Exhibit  "B"  attached  hereto  and made part
hereof.  "Delivery  of  Possession"  of the Leased  Premises by Lessor to Lessee
shall be deemed to have been made when Lessor's  architect  certifies in writing
that construction of the Leased Premises shall have been completed.

         2.   TERM
              ----

              The term (the  "Term")  of this  Lease  shall be for a term of Ten
(10) years,  commencing on the 1st day of March, 1991, (the "Commencement Date")
and shall  expire on the last day of  February,  2001.  If the Term of the Lease
does not begin on the date specified  herein for reasons other than the fault of
Lessee,  then the expiration date shall be moved for the commensurate  amount of
the delay and the rent shall be prorated  accordingly.  If the term commences or
ends  in  mid-month,  the  rent  payable  for  that  month  (including,  without
limitation,  Additional  Rent)  shall  be  prorated  and  paid  on the  date  of
commencement or termination.

         3.   RENT
              ----

              (a)  The rent (the "Base Rent") shall be:



                                      - 4 -


<PAGE>





            Year           Square Foot Rate
            ----           ----------------

              1                 $ 6.75
              2                 $ 7.75
              3                 $ 8.75
              4                 $ 9.50
              5                $ 10.00
              6                $ 10.30
              7                $ 10.61
              8                $ 10.93
              9                $ 11.26
             10                $ 11.59


The term "Lease Year" shall mean each twelve (12) month  period  during the term
of this  Lease  commencing  on the  Commencement  Date.  The Base Rent  shall be
payable,  in  advance,  in  equal  monthly   installments,   the  first  monthly
installment to be due and payable on the  Commencement  Date and each subsequent
monthly  installment  to be due and  payable  on the first day of each and every
month thereafter during the term of this Lease.

              (b)  All moneys  payable by Lessee  under the terms of this Lease,
other than Base Rent, as adjusted from time to time, shall be deemed "Additional
Rent."

              (c)  Lessee  shall make all  payments of Base Rent and  Additional
Rent on a  timely  basis,  without  demand  and  without  deduction,  setoff  or
counterclaim,  except as  expressly  permitted in Paragraph  29(b)  hereof.  All
payments  of Rent and  Additional  Rent  shall be made by good and valid  check,
payable to The Anastasi  Stephens Group,  Inc.,  agent,  4483 Forbes  Boulevard,
Lanham,  Maryland  20706,  or to such other  party or to such  other  address as
Lessor may designate  from time to time by written  notice to Lessee.  If Lessor
shall at any time or times  accept Base Rent or  Additional  Rent after it shall
become due and payable,  such acceptance  shall not excuse delay upon subsequent
occasions, or constitute,  or be construed as, a waive of any or all of Lessor's
rights  hereunder.  If any payment of Base Rent or  Additional  Rent is not made
within  ten (10) days of when due,  a late  charge of five  percent  (5%) of the
amount of such payment shall be imposed, Lessor shall be entitled to require the
payment of Base Rent and Additional Rent by certified check if the check for any
payment by Lessee shall be dishonored by its Bank.

              (d)  Except  for the  obligations  of Lessor  expressly  set forth
herein,  this  Lease is a "net  lease" and Lessor  shall  receive  the Base Rent
hereinabove  provided as net income from the Leased Premises,  not diminished by
any  imposition  of any expenses or charges  required to be paid to maintain and
carry the Leased  Premises or to continue the  ownership  of Lessor,  other than
payments  under any mortgages now existing or hereafter  created by Lessor,  and
Lessor is not and shall not be  required  to render any  services of any kind to
Lessee.




                                      - 5 -


<PAGE>





         4.   SECURITY DEPOSIT
              ----------------

              (a)  Lessee has, simultaneously  with the execution of this Lease,
deposited with Lessor, in cash or by check subject to collection, the sum of Ten
Thousand and No/100 Dollars ($10,000.00). Said deposit shall be held as security
for the faithful performance by Lessee of the terms,  covenants,  provisions and
conditions  of this  Lease.  It is agreed that in the event  Lessee  defaults in
respect to any of the terms, covenants, provisions and conditions of this Lease,
including (but not limited to) the payment of Base Rent or Additional  Rent, and
fails to cure any such defaults within applicable grace periods, Lessor may use,
apply or  appropriate  the whole or any part of the security so deposited to the
extent  required for the payment of any Base Rent or Additional  Rent or for the
curing of any  defaults by Lessee  hereunder  pursuant to  Paragraph  29 hereof;
provided,  however,  that no such  use,  application,  or  appropriation  of the
deposit shall be deemed to relieve  Lessee of any breach of this Lease and shall
be in addition to other remedies under this Lease.

              (b)  Should  the  entire   deposit  or  any  portion   thereof  be
appropriated and applied by Lessor under the foregoing  provisions,  then Lessee
shall (upon the written demand of Lessor) forthwith remit to Lessor a sufficient
amount in cash to restore  said  security to the  original  sum  deposited,  and
Lessee's  failure  to do so within ten (10) days  after  receipt of such  demand
shall itself constitute an event of default under this Lease.

              (c)  The security deposit (less any amounts applied as provided in
subsection  (a) above) shall be returned to Lessee within thirty (30) days after
the date  fixed as the end of the Term of this  Lease  and  delivery  of  entire
possession of the Leased Premises to Lessor.

              (d)  In the event of a sale, leasing or other transfer of the land
and building of which the Leased  Premises  forms a part,  Lessor shall have the
right to transfer the security and be released by Lessee from all  liability for
the return of such security deposit.  Lessee shall look to the new Lessor solely
for the return of said  deposit.  The  provisions of this  Paragraph  4(d) shall
apply to every  transfer or  assignment  made of the  security  deposit to a new
Lessor.

              (e)   Lessee covenants  that it will not  assign  or  encumber  or
attempt to assign to encumber  the  security  deposited  herein and that neither
Lessor  nor its  successors  or assigns  shall be bound by any such  assignment,
encumbrance, attempted assignment or attempted encumbrance.

              (f)  Lessee shall not be entitled to any  interest on the security
deposit, and such funds need not be segregated or held as escrow by Lessor.

              (g)  It is expressly understood  and agreed that,  in the event of
any  termination  of this  Lease or  re-entry  upon or  reletting  of the Leased
Premises on account of any default on the part of Lessee under this Lease, then,




                                      - 6 -


<PAGE>




and in such event, the deposit shall be retained and be subject to appropriation
by Lessor  until this  Lease  would,  by its terms,  have  expired  absent  such
default.

         5.   USE
              ---

              Lessee  will use and  occupy the  Leased  Premises  solely for the
purpose of Offices and operation of a vaccine research and production  facility.
The Leased  Premises  may not be used for any other  purpose  without  the prior
written consent of Lessor, which consent shall not be unreasonably withheld. The
Leased  Premises shall not be used for the storage,  distribution or sale of any
pornographic  or  "adult  rated"  materials.  Lessee  shall  not use the  Leased
Premises for any purpose or activity which is noxious or unreasonably  offensive
because of the emission of noise, smoke, dust,  vibration or odors. Tenant shall
not use the plumbing  facilities for any purpose injurious to same or dispose of
any  garbage or any other  foreign  substance  therein,  nor place a load on any
floor in the Leased  Premises  exceeding  the floor load of 250 per square  foot
which such floor was designed to carry, nor install,  operate and/or maintain in
the Leased  Premises and heavy  equipment  which could cause injury to the Lease
Premises,  nor  install,  operate  and/or  maintain in the Leased  Premises  any
electrical  equipment which will overload the electrical system therein,  or any
part hereof,  beyond its capacity for proper and safe operation as determined by
the Lessor or which does not bear underwriter's  approval.  Lessee shall not use
the Leased  Premises in any manner or for any purpose  which  violates any rule,
regulation, law, ordinance, or requirements of any governmental agency.

         6.   TAXES

              (a)  As  additional  rent  hereunder,  at least  thirty  (30) days
before  any fine,  penalty  or  interest  or cost may be added  thereto  for the
non-payment  thereof (or sooner if elsewhere herein required),  Lessee shall pay
throughout  the term of this Lease all  levies,  taxes,  assessments,  water and
sewer  rents and  charges,  liens,  charges for public  utilities  and all other
charges,  imposts  or burdens of  whatsoever  kind and nature  which at any time
during the term of this Lease may be assessed or imposed by any  federal,  state
or  municipal  government  or  public  authority,  or under  any law,  ordinance
regulation  thereof or pursuant to any recorded  covenants or agreements (all of
which are hereinafter referred to as "Impositions"), upon or with respect to the
Leased Premises,  any improvements  made thereto,  or this Lease.  Additionally,
Lessee shall pay a  proportionate  share of any imposition  which is not imposed
upon the Leased Premises as a separate entity but which is imposed upon the land
or the  building  or upon the  appurtenances,  leases,  rents,  transactions  or
documents  relating  to the lot or the  building.  Provided,  however,  that any
imposition  shall be apportioned for the first and last fiscal tax years covered
by the term hereof.  "Impositions" shall include, but not be limited to, any and
all governmental or  quasi-governmental  levies,  fees,  assessments,  taxes and
charges,  general  and  special,   ordinary  and  extraordinary,   foreseen  and
unforeseen,  of any kind and nature  whatsoever,  with  respect to such land and


                                      - 7 -


<PAGE>



building  (excluding  taxes paid on Lessor's  income but including  sales tax or
excise tax imposed by any  governmental  authority upon the Base Rent payable by
Lessee hereunder).

              (b)  Notwithstanding  the foregoing  provisions of this Article 6,
Lessor shall have the right,  at its option,  to require Lessee to pay to Lessor
or to any  mortgagee,  at the time when the monthly  installment of Base Rent is
payable,  an amount equal to  one-twelfth  (1/12) of the annual  Impositions  as
estimated by Lessor. If Lessor elects to have Lessee make such payments,  Lessee
also  shall  pay to Lessor  or to such  mortgagee,  as the case may be, at least
thirty (30) days before any fine, penalty, interest or cost may be added thereto
for the non-payment  thereof,  the amount by which the Impositions  becoming due
exceed the monthly  installment  payments on account thereof  previously made by
Lessee.  Should  Lessee's  monthly  installment  payments on account of Lessee's
share of Impositions for any tax year exceed the actual amount of Lessee's share
of such  Impositions,  the excess  amount  shall be  credited  against  Lessee's
installments for Impositions thereafter becoming due. The amounts paid by Lessee
pursuant to this  paragraph (b) shall be used to pay the  Impositions,  but such
amounts  shall not be deemed to be trust funds and no interest  shall be payable
thereon.

              (c)  During any part of the Term of this Lease which shall be less
than a full tax  fiscal  year,  any Taxes  shall be pro  rated on a daily  basis
between  the  parties,  to the end that Lessee only shall pay its share of Taxes
attributable to the portion of the tax fiscal years occurring within the term of
this Lease.

              (d)  Lessee shall pay  promptly,  and when due,  all taxes,  fees,
licenses,  assessments  and other charges levied or imposed upon the business of
the  Tenant  or upon  any  fixtures,  furnishings  or  equipment  in the  Leased
Premises.

              (e)  If due to a future change in the method of taxation or in the
taxing authority,  a franchise,  gross receipts,  transit,  rent or other tax or
other  governmental  imposition,  however  designated,  shall be levied  against
Lessor in  substitution  (in whole or in part)  for,  or in  addition  to,  said
"Impositions"  as  currently  defined),  then such  franchise,  gross  receipts,
transit,  rent or other tax or  governmental  Impositions  shall be deemed to be
included within the definition of "Impositions"  for the purposes of this Lease.
The term  "Impositions"  also  includes  all costs  reasonably  incurred  in any
proceeding brought by Lessor to reduce said Taxes.

              (f)  Lessor may  institute  any  proceedings  with  respect to the
assessed valuation of Park Place or any part thereof, and Lessee shall cooperate
with, and participate in, any and all such  proceedings.  If, after Lessee shall
have made the required payment of Taxes hereunder, Lessor shall receive a refund
of any portion thereof,  then, within thirty (30) days after Lessor's receipt of
such refund, Lessor shall pay to Lessee Lessee's pro rata share of the amount of
the  refund,  less all  costs  and  expenses  (including,  but not  limited  to,
attorneys' and appraiser'  fees) expended for incurred in obtaining such refund.
Lessee may not institute any proceedings with respect to the assessed  valuation
of Park Place or any part thereof.


                                      -8-
<PAGE>


         7.   UTILITIES
              ---------

         Starting with the Commencement Date and continuing  throughout the Term
of this Lease, Lessee shall be solely responsible for and shall pay, as and when
the same become due and payable and as hereinafter  provided,  all rents, rates,
costs and charges for water  services,  sewer service,  electricity,  gas, heat,
steam,  power,  telephone  (and  other  communication  services),  and any other
utilities or services  rendered or supplied to, upon or in  connection  with, or
used or consumed  within or in  servicing,  the Leased  Premises,  and all other
utility costs and expenses involved in the use of the Leased Premises throughout
the term of this  Lease,  and Lessee  shall  indemnify  Lessor  and save  Lessor
harmless  against  any  costs  liability  or  damages  on such  account.  Unless
otherwise  agreed in writing by Lessor or Lessee,  Lessee  shall,  promptly upon
Delivery of Possession of the Leased  Premises and at Lessee's own expense,  pay
for the  installation of separate meters for all utilities  servicing the Leased
Premises  and place said meters and  related  utility  accounts in Lessee's  own
name.  Lessee shall pay all separately  metered charges to the respective public
utility companies.  With respect to each utility which is not separately metered
for the Leased Premises,  Lessee shall pay Lessor, as Additional Rent,  Lessee's
proportionate  share of the total cost and fees therefore  attributable to those
areas of the warehouse/office buildings which are not separately metered.

         8.   COMMON AREA MAINTENANCE
              -----------------------

              (a)  Subject to the  provisions  of this Lease,  Lessor  grants to
Lessee, its employees, agents, customers and invitees during the Term hereof the
non-exclusive use, in common with Lessor and other tenants and occupants of Park
Place and their  respective  employees,  agents,  customers  and invitees and in
common  with such  others  as Lessor  may  designate  from time to time,  of all
non-allocated  parking  areas  within Park Place for  pedestrian  and  vehicular
ingress and egress and the accommodation and parking areas within Park Place for
pedestrian and vehicular  ingress and egress and the  accommodation  and parking
automobiles as required by the Lessee in conducting  normal business  activities
of Lessee within the Leased  Premises.  Lessor reserves the right,  however,  to
designate certain portions of the parking areas within Park Place for parking of
trucks,  vans, and other vehicles,  and to designate for the specific account of
Lessee,  or other  tenants  in Park  Place,  specific  parking  areas or  spaces
constructed within Park Place.  Notwithstanding anything contained in this Lease
to the contrary, Lessor shall have the right, at any time and from time to time,
to change the size,  location  and nature of the  parking  areas (so long as the
number of parking  spaces is not reduced)  and/or other common areas within Park
Place. All parking areas and related facilities which may be furnished by Lessor
in or near the Leased Premises,  including  employee parking areas, truck way or
ways, loading docks, pedestrian sidewalks and ramps, landscaped areas, and other
areas and  improvements  which may be provided by Lessor for the general use, in
common with Lessor and other tenants,  and their respective  employees,  agents,
customers  and invitees,  shall at all time be subject to the exclusive  control


                                       -9-

<PAGE>



and management of Lessor, and Lessor shall have the right, from time to time, to
establish,  modify and enforce  reasonable rules and regulations with respect to
all parking areas and other  facilities and areas  mentioned in this  paragraph.
Lessee agrees to abide by and conform with all such rules and  regulations  upon
notice thereof and to cause its employees,  agents, customers and invitees to do
the same.  Lessor shall have no liability to Lessee for use of the parking areas
by Lessor or other  tenants  and  occupants  of Park Place and their  respective
employees, agents, customers, or other third parties. No provision of this Lease
shall be  construed  as a demise to Lessee of the  parking  or any other  common
area) within Park Place.  If any repairs  (excluding  repairs caused by Lessee's
normal  use) to the  parking  or  other  common  areas  within  Park  Place  are
necessitated  by reason  of any act or  omission  by  Lessee  or its  employees,
agents, customers or invitees, then, if Lessor chooses to do so, Lessor may make
such repairs and Lessee shall promptly upon demand reimburse Lessor for the full
costs to the extent same are not covered by Lessor's  insurance,  or at Lessor's
option,  Lessor may notify Lessee of the necessity for such repairs, and Lessee,
at its cost and expense,  shall,  with due  diligence,  commence and complete to
Lessor's  satisfaction  the repairs within ten (10) days of Lessee's  receipt of
such notice.

              (b)  "Common  Area  Charges"  means all of the costs and  expenses
which are incurred by Lessor with respect to operation, management,  maintenance
and security of the building  including the parking and other designated  common
areas in Park Place and the exterior  walls of the buildings in Park Place,  and
those areas of Park Place which house mechanical,  electrical or other equipment
or are otherwise  determined from time to time by Lessor to be used in operating
or maintaining Park Place.  "Common Area Charges"  include,  but are not limited
to,  the cost of  maintaining,  repairing,  and  replacing  and  repaving  (when
necessary) the parking and other designated  common areas;  supplies,  tools and
materials  purchased and/or used in connection with repairs,  maintenance and/or
replacements;  wages,  salaries,  and fringe  benefits of all  employees  of the
Lessor for the  portion  of time they are  directly  engaged  in the  operation,
maintenance  and  security  of Park  Place,  including  license  and  fees  (but
excluding wages, salaries and benefits of executive  employees);  removing snow,
ice,  and debris from the  roadways  and parking  areas for  Lessee's use during
normal  business hours;  removal of customary and normal trash;  maintaining and
repairing or repainting (when necessary)  directional signs,  pavement markings,
and parking lot  striping;  repairing  and replacing  (when  necessary)  outdoor
lighting  facilities;  maintaining  the  grass  and  otherwise  caring  for  the
replanting (when  necessary) all shrubbery and landscape  areas;  providing such
security as Lessor,  in its sole  discretion,  deems  advisable;  accounting and
legal fees for common areas at Park Place; utilities,  heating,  ventilation and
air-conditioning charges allocable to designated common areas and other building
service areas.

              (c)  Starting with the Commencement Date and continuing throughout
the Terms of this  Lease,  Lessee  shall pay Lessor in  advance  as  hereinafter
described and as Additional  Rent,  Lessee's  Pro-Rata  Share of all Common Area
Charges for said period.  "Lessee's  Pro-Rata  Share"  shall be a fraction,  the
numerator  of which shall be the floor area within the Leased  Premises  and the
denominator  of which shall be the total floor area within all buildings in Park
Place. The Initial Lessee's Pro-Rata Share shall be 8%.


                                      -10-
<PAGE>



              (d)  On or before the  Commencement  Date, on or before the end of
each and every Lease year,  and at such other time(s) as is deemed  desirable by
lessor in its sole  discretion,  Lessor  shall  forward to Lessee a "Common Area
Charges  Statement",  which shall contain Lessor's latest estimate of the Common
Area  Charges  for the then  current or the then  upcoming  (as the case may be)
Lease Year,  and a statement  of Lessee's  Pro-Rata  Share  thereof.  Landlord's
failure to forward,  or to timely  forward,  any Common Area  Charges  Statement
shall not excuse Lessee from its liability for Lessee's Pro-Rata Share of Common
Area Charges.

              (e)  Each  month  during the Term of this  Lease,  along with each
monthly  installment of Base Rent,  beginning with the Commencement Date, Lessee
shall pay to Lessor,  in advance,  an amount  equal to  one-twelfth  (1/12th) of
Lessee's  Pro-Rata  Share of the  Common  Area  Charges as set forth in the then
latest Statement.  If the Commencement Date is a day other than the first day of
a calendar month, then the amount of Common Area Charges due for the first month
and the last month of the Term shall be pro rated on the basis of a thirty  (30)
day month. As soon as practicable near the end of each and every Lease Year, but
no later than 90 days after the end of the Lease year,  Lessor  shall  submit to
Lessee an "Actual Common Area Charges Statement" prepared by Lessor showing what
the Common Area Charges for the then preceding  Lease Year actually  were.  With
the next monthly  installment  of Base Rent due after  Lessee's  receipt of such
Statement,  Lessee shall pay Lessor or Lessor shall credit  Lessee,  as the case
may be the difference  between Lessee's Pro-Rata Share of the actual Common Area
Charges  for said  Lease  Year as shown on said  Statement  and the total of all
Common Area Charges paid by Lessee to Lessor for said Lease Year.

         9.   NON-LIABILITY OF LESSOR
              -----------------------

              (a)  Except  as  otherwise  expressly  provided  in this  Lease or
unless caused by the negligence or intentional  misconduct of Lessor or Lessor's
employees,  agents  and  contractors  while  acting  within  the  scope of their
employment,  Lessor shall not be responsible or liable to Lessee for any loss or
damage to persons or property,  or any  interference or interruption of Lessee's
use of the Leased  Premises,  that may be occasioned by (i) water,  gas,  steam,
wind or the bursting, stoppage or leaking of any pipes, sewer or water lines, or
other  conduits,  fixtures or equipment;  (ii) the  interruption  of any utility
services  to the  Leased  Premises  caused  by the  utility  company;  (iii) any
repairs,  alterations,  maintenance or additions to the Leased  Premises or land
and  building of which they are a part;  (iv) any  casualty;  (v) theft or other
criminal  conduct;  or (vi) the acts or omissions of persons occupying any space
adjacent to the Leased Premises.

              (b)  No  provisions  of this  lease  shall be deemed to confer any
rights  upon any persons or  entities  other  than the  parties  to this  Lease,
permitted successors and assigns and mortgages.


                                      -11-
<PAGE>



              (c)  Notwithstanding  anything  to the  contrary  provided in this
Lease, it is  specifically  understood and agreed that there shall be absolutely
no personal  liability on the part of Lessor,  including  partners in Lessor and
their  respective  successors  and assigns,  with respect to its  performance or
observance of any of the terms, covenants and conditions of this Lease, and that
Lessee shall look solely to the equity of the Lessor in the land and building of
which the Leased  Premises  form a part for the  satisfaction  of each and every
remedy  of Lessee  in the  event of any  breach  by Lessor of any of the  terms,
covenants  and  conditions  of this Lease to be performed or observed by Lessor,
such exculpation of personal  liability to be absolute and without any exception
whatsoever.

              (d)  If  Lessor  shall  fail  to  comply  fully  with  any  of its
obligations under this Lease,  Lessee may seek and enforce specific  performance
of the Lease against Lessor and pursue such other  equitable  remedies as may be
available to Lessee.  Notwithstanding  the foregoing,  the result of such action
shall be subject to the provisions of Paragraph 9(c) hereof.

         10.  INDEMNITY
              ---------

              Lessee  agrees to  indemnify  and save  Lessor  harmless  from and
against any and all claims,  demands,  costs and  expenses  (including,  but not
limited  to,  reasonable  attorneys'  fees  and  litigation  costs)  for,  or in
connection  with,  any  accident,  injury or damage  whatsoever to any person or
property (i) arising directly or indirectly out of Lessee's use or occupation of
the Leased  Premises,  (ii) occurring in, on or about the Leased  Premises or on
the sidewalks  adjoining the same, or (iii) arising  directly or indirectly from
any act or  omission of Lessee or any of Lessee's  licenses,  servants,  agents,
employees or  contractors.  The foregoing  indemnity shall not apply to any such
claim or demand proximately caused by the negligence or misconduct of Lessor, or
its  employees,  agents and  contractors  while acting within the scope of their
employment.

         11.  LIABILITY INSURANCE
              -------------------

              (a)  Lessee,  at Lessee's sole expense,  shall obtain and maintain
in  effect at all  times  starting  with the  Commencement  Date and  continuing
throughout the term of this Lease, a policy or policies of comprehensive general
public liability insurance,  insuring Lessor,  Lessor's  mortgagee(s) and Lessee
against any liability for injury, death or property damage occurring upon, in or
about any part of the Leased Premises or any  appurtenances  thereto,  affording
protection  to the limits of not less than One Million  Dollars  ($1,000,000.00)
with  respect  to bodily  injury or death of any one  person,  and not less than
Three Million Dollars  ($3,000,000.00) with respect to any one incident, and not
less than Five Hundred Thousand Dollars  ($500,000.00)  with respect to property
damage.  The foregoing  minimum  limits may, at Lessor's  option and upon thirty
(30) days' notice to Lessee, be increased from time to time to reflect inflation
or changed conditions.

              (b)  The insurance  policy(ies)  required to be procured by Lessee
under this Lease:


                                      -12-
<PAGE>


              (i)   Shall be issued by a reputable insurance company licensed to
do  business  in the State of  Maryland  and shall have such form and content as
shall be approved by Lessor.

              (ii)  Shall  be written  as  primary   policy   coverage  and  not
contributing with, or in excess of, any coverage which Lessor may carry.

              (iii) Shall have an endorsement  thereto to the effect that no act
or omission by Lessee shall affect the  obligation  of the insurer to pay Lessor
the full  amount of any loss  sustained  by Lessor and shall  contain an express
waiver of any right of subrogation by the insurance company against Lessor,  its
agents and employees.

              (iv)  Shall name Lessor as an additional named insured.

              (c)  On or before the Commencement Date, and at least fifteen (15)
days before the expiration date of the policy,  Lessee shall deliver to Lessor a
certificate  of insurance  evidencing  the  existence  and good  standing of the
liability  policy  referred to in Paragraph  11(a),  together  with  evidence of
payment of all premiums.  The insurance  required to be carried under this Lease
may be carried  under a blanket  policy  covering the Leased  Premises and other
locations of Lessee. The insurance policy required to be carried by Lessee shall
provide  that such  insurance  policy  shall not be canceled  unless  Lessor and
Lessor's mortgagee(s) shall have received thirty (30) days' prior written notice
of cancellation.  In the event that Lessee shall,  prior to the thirtieth (30th)
day  before  any  insurance  policy  will  lapse or  terminate,  fail to furnish
evidence of the coverage and pay the premium therefor for a period not exceeding
one year,  and the  premiums  so paid by Lessor  shall be payable by Lessee,  on
demand, as Additional Rent.

         12.  HAZARD INSURANCE
              ----------------

              (a)  Starting with the Commencement Date and continuing throughout
the Term of this  Lease,  Lessee  shall pay to Lessor,  or such  other  party as
Lessor shall designate by written notice to Lessee, as Additional Rent, Lessee's
Pro-Rata Share, as defined in Paragraph 12(e) hereof,  of the premiums and other
charges (the "Premiums") that may be incurred or contracted for or by Lessor for
fire and casualty  insurance  coverage  for the land and  buildings of which the
Leased  Premises form a part,  including  protection  from such perils as may be
insured against under a broad form extended coverage  endorsement or on all risk
of physical loss policy,  and further  including  loss of rental  coverage in an
amount equal to the Rent for one (1) Lease Year.  The premiums for all insurance
to be  obtained  by  Lessor  under  this  Paragraph  12(a)  shall be  reasonably
competitive  with the  premiums  charged for  similar  insurance  protection  by
reputable  insurers for  comparable  properties.  Lessee agrees that it will not
store  gasoline or other  explosive,  flammable or toxic  material in the Leased
Premises or do anything which may cause Lessor's  insurance  company to void the
policy covering the Leased Premises or to increase the premium thereon, and that


                                      -13-
<PAGE>



Lessee will  immediately  conform to all rules and regulations from time to time
made or established by Lessor's  insurance  company or insurance  rating bureau.
Lessor will do everything reasonably possible and consistent with the conduct of
Lessee's  business  to obtain the lowest  possible  rates for  insurance  on the
Leased Premises.  If, however,  the cost to Lessor of obtaining insurance on the
Leased  Premises  (or the  building  which the Leased  Premises  are located) is
increased  due to the  Lessee's  occupancy  thereof,  and the  Lessor's  insurer
provides evidence that said increase is the direct cause of Lessee's  occupancy,
Lessee agrees to pay,  promptly  upon demand,  as  additional  rental,  any such
increase.

              (b)  On or before the Commencement Date and before the due date of
each and  every  bill for the  Premiums,  Lessor  shall  forward  to  Lessee  an
"Insurance  Statement" which shall contain an estimated  statement of the amount
due from Lessee from time to time as Lessee's  Pro-Rata  Share of the  Premiums.
Lessor's failure to forward, or to timely forward, any Insurance Statement shall
not  excuse  Lessee  from  its  liability  for  Lessee's  Pro-Rata  Share of the
Premiums.

              (c)  Each and every  month  during the Term of this  Lease,  along
with its monthly installment of Fixed Rent,  beginning on the Commencement Date,
Lessee  shall pay  Lessor  an amount  equal to  one-twelfth  (1/12) of  Lessee's
Pro-Rata  Share  of the  Premiums  as set  forth in the  then  latest  Insurance
Statement,  which  shall  be  credited  toward  Lessee's  Pro-Rata  Share of the
Premiums when the same are due and payable.  Should Lessee's monthly installment
payments on account of Lessee's Pro-Rata Share of the Premiums for the period to
which the Premiums relate exceed the actual amount of Lessee's Pro Rata Share of
such Premiums, the excess amount shall be credited against Lessee's installments
for Premiums thereafter becoming due. If the Commencement Date is other than the
first day of a period to which the Premiums relate, then the installments of the
Premiums  due from the Lessee  shall be pro rated on the basis of a thirty  (30)
day month.

              (d)  Notwithstanding  the  provisions  of  Paragraph  12(c) above,
Lessor may, upon ten (10) days' written notice to Lessee,  require Lessee to pay
Lessee's  Pro- Rata Share of the  necessary  increased  Premiums due to Lessee's
occupancy at such times as the  Premiums  are due and payable to the  respective
insurance  company or companies or in such manner as is required of Lessor under
any mortgage, whether such payments be in lump sum or other installments.

                  (e)  Lessee's  Pro-Rata  of the  Premiums  shall be of all the
Premiums due for the land and building of which the Leased Premises form a part.
As used in this Paragraph 12, "Lessee's Pro Rata Share" shall be a fraction, the
numerator  of which shall be the floor area within the Leased  Premises  and the
denominator  of which shall be the total floor area within the building of which
the Leased Premises form a part.

              (f)  Lessor  hereby   releases   Lessee  from  any  liability  and
responsibility  to Lessor to anyone  claiming  through or under Lessor by way of
subrogation or otherwise,  for any and all loss or damage to the Leased Premises


                                      -14-
<PAGE>



caused by fire or any  casualty  covered by  insurance  to the extent  insurance
proceeds are received  therefor,  even if such fire or other casualty shall have
been caused by the fault or negligence of Lessee,  or anyone for whom Lessee may
have been responsible.  Lessor's  insurance  policies shall include  appropriate
clauses (i) waiving all rights of  subrogation  against  Lessee with  respect to
losses payable under such  policies,  and (ii) agreeing that such policies shall
not be  invalidated  should the insured waive in writing prior to a loss any and
all rights of recovery against the other party hereto for losses covered by such
policies.

         13.  DAMAGE TO THE DEMISED PREMISES
              ------------------------------

              (a) In the event of partial or total damage or  destruction of the
Leased  Premises  by fire,  other  casualty,  or any  cause  whatsoever  (except
condemnation),  Lessee shall give immediate  notice to Lessor.  If the damage or
destruction  is insured  against by Lessor,  this Lease  shall  continue in full
force and effect,  and, to the extent that insurance  proceeds  respecting  such
damage or  destruction  are  subject  to being  utilized  and,  in fact,  may be
utilized by Lessor for repair,  Lessor shall cause such damage or destruction to
be repaired with reasonable speed at the expense of Lessor,  except as otherwise
hereinafter  provided  in this  Paragraph  13. If in the  reasonable  opinion of
Lessor the damage or destruction  is such that repair thereof cannot  reasonably
be  completed  within  ninety  (90) days of the date the  damage or  destruction
occurs,  Lessor  shall have the right to  terminate  this Lease by the giving of
written  notice to such effect to Lessee  within thirty (30) days of the date of
Lessor's receipt of Lessee's notice of damage or destruction.  In no event shall
Lessor be  required  to restore or repair  Lessee's  personal  property or other
contents within the Leased Premises.  Due allowance shall be made for reasonable
delay which may arise by reason of Lessor's  adjustment of loss under  insurance
policies  and on account of labor  troubles or any other cause  beyond  Lessor's
control. To the extent that the Leased Premises are rendered  untenantable,  the
Rent  and  Additional  Rent  shall  proportionately  abate.  If  the  damage  or
destruction  is not covered by  insurance  maintained  by Lessor or if insurance
proceeds  respecting the damage or destruction are not subject to being utilized
for repair and, in fact, may be not so utilized, Lessor shall not be required to
repair the damage or  destruction.  In the event the damage or destruction is so
extensive to the  building of which the Leased  Premises are a part as to render
it uneconomical, in Lessor's opinion, to restore the Leased Premises, the Lease,
at the option of Lessor,  shall be terminated  upon written notice to Lessee and
Lessee shall immediately thereafter vacate the Leased Premises and surrender the
same to Lessor.  No such termination  shall release Lessee from any liability to
Lessor from any of the  obligations or duties imposed on Lessee under this Lease
prior  to the  damage.  Upon  any  termination  of this  Lease  pursuant  to his
Paragraph 13(a),  Rent and Additional Rent shall be prorated and adjusted to the
date of such termination.

              (b) Lessee  hereby  waives any and all right of recovery  which it
might  otherwise  have against  Lessor,  its agents and  employees,  for loss or
damage to Lessee's contents, furniture, furnishings, fixtures and other property
removable  by Lessee under the  provisions  of this Lease to the extent that the


                                      -15-
<PAGE>



same is to be covered by Lessee's insurance  thereunder,  except where such loss
or damage  may  result  from the  negligence  of fault of  Lessor,  its  agents,
employees or contractors.

         14.  EMINENT DOMAIN
              --------------

              (a) If during the term of this Lease, the Leased Premises, or such
a  substantial  portion of the Leased  Premises  as shall  prevent  Lessee  from
conducting its normal business, shall be taken by proper authority for public or
quasi-public  use, then Lessee may terminate this Lease by giving Lessor written
notice of  termination  within  thirty (30) days after  receipt of notice of the
taking,  and Lessee's  obligation  to pay rent,  taxes,  and other charges shall
terminate as of the date of the termination notice. If only a part of the Leased
Premises is taken and the part not taken shall be reasonably  sufficient for the
purpose of conducting Lessee's normal business,  this Lease shall remain in full
force  and  effect,   except  that  the  Rent  and  Additional   Rent  shall  be
proportionately reduced.

              (b) All compensation awarded for any taking shall belong to and be
the property of Lessor. Nothing contained herein, however, shall be construed to
preclude  Lessee from  prosecuting  any claim  directly  against the  condemning
authority  for loss of  business or  depreciation,  damage or cost of removal of
personal property  belonging to Lessee so long as the claim does not diminish or
otherwise  adversely  affect  Lessor's award or the award  otherwise  payable to
Lessor's mortgagee.

         15.  CONDITION OF LEASED PREMISES; MAINTENANCE AND REPAIR
              ----------------------------------------------------

              (a) Except for the repairs that Lessor is  specifically  obligated
to make  under  Paragraph  15(b)  hereof,  and  except  for  repairs  covered by
contractor  warranties held by Lessor for Lessor's  benefit,  during the term of
this Lease,  Lessee, at Lessee's sole cost and expense,  shall promptly make all
repairs,  perform all maintenance,  perform all custodial  services and make all
replacements  in and to the Lease  Premises  that are necessary in order to keep
the  Leased  Premises  in good  order and  repair  and in a safe and  tenantable
condition. Without limiting the generality of the foregoing, Lessee, at its sole
cost and expense,  is specifically  required to make promptly all repairs to (i)
any pipes,  water and waste lines,  ducts,  wires or conduits  beneath or in the
Leased  Premises  or within the ceiling of the Leased  Premises;  (ii) any glass
windows included within the Leased Premises;  (iii) Leasee's  sign(s);  (iv) any
electrical,  natural gas (if any),  heating,  ventilating and air  conditioning,
plumbing,  and other  systems,  equipment,  fixtures  and items  installed in or
servicing the Leased Premises; (v) the floors,  ceilings and walls of the Leased
Premises;  (vi) the entrance and exit and auxiliary driveways, if any, which are
part of and  service  the Leased  Premises;  and (vii) any portion of the Leased
Premises  damaged by Lessee's use or occupancy of the Leased  Premises or by any
act,  omission or  negligence  of Lessee,  or any of its  respective  employees,
agents, invitees,  licensees or contractors.  All repairs, and replacements made
by Lessee shall  utilize  materials  and  equipment  which are at least equal in
quality and usefulness to those originally used in the Leased Premises.  Lessee,


                                      -16-
<PAGE>



at Lessee's expense,  shall enter into one (1) or more service contracts for the
maintenance  of the  heating,  ventilating  and  air  conditioning  systems  and
equipment.  Lessee shall keep the Leased Premises free of all insects,  rodents,
vermin and pests of every type and kind. Lessee shall also,  promptly and at its
own expense,  keep any sidewalks and curbs adjacent to the Leased Premises clean
and free from snow,  ice,  dirt and rubbish.  Lessee  shall not  (directly or by
sufferance)  place any equipment,  materials or debris on the roof of the Leased
Premises, or cut, drive nails into or otherwise mutilate such roof.

              (b) Lessor shall within thirty (30) days (or such longer period of
time as may  reasonably be required by Lessor) after written  notice from Lessee
with respect thereto,  make necessary  structural  repairs to the exterior walls
and shall keep in good order,  condition  and repair the  exterior  foundations,
downspouts,  gutters  and roof of the  Leased  Premises  and the  portion of the
plumbing  and sewage  system  located  outside the  building in which the Leased
Premises are located (it being understood and agreed that Landlord's obligations
exclude the exterior and interior of all windows,  doors, plate glass and signs,
and repairs required by any casualty except as otherwise covered by Paragraph 13
herein).  Lessee shall,  upon demand,  reimburse  Lessor for reasonable costs of
making any such repairs or  replacements  caused by Lessee's use or occupancy of
the Leased  Premises  or by any act,  omission  or  negligence  of  Lessee,  any
subtenant or concessionaire of Lessee,  or their respective  employees,  agents,
invitees,  licensees or contractors (excluding repairs or replacements caused by
Lessee's normal use).

              (c) Lessee  hereby  covenants  to contain  all  garbage,  rubbish,
waste,  trash and debris  generated  in  conjunction  with its use of the Leased
Premises in  containers  provided by Lessor (which shall be emptied no more than
three times per week, but at least once a week) so as not to constitute a safety
or fire hazard.

         16.  ALTERATIONS
              -----------

              Lessee  shall not make any  non-structural  interior  alterations,
additions or improvements in or to the Leased Premises without the prior written
consent of Lessor in each  instance,  which  consent  shall not be  unreasonably
withheld  or  delayed.   Lessee  shall  not  take  any  structural  or  exterior
alterations,  additions or improvements to the Leased Premises without the prior
written  consent of Lessor.  Should Lessor fail to respond  within  fifteen (15)
working  days after  Lessor's  receipt of any  written  request  from Lessee for
Lessor's  consent  to  any  proposed  alterations,  additions  or  improvements,
Lessor's   consent  shall  be  deemed  to  have  been  granted.   All  permitted
alterations, additions and improvements made by Lessee shall be performed (i) in
a good and workmanlike  manner, (ii) in accordance with all applicable legal and
insurance  requirements,  (iii) only after receipt by Lessee and presentation to
Lessor of all necessary permits and licenses, and (iv) at Lessee's sole expense.
Except for Lessee's removable trade fixtures, and all improvement made by Tenant
in the processing and storage areas, all improvements,  repairs, alterations and
additions and all other non-trade  fixtures,  whether  installed before or after
the  execution  of this  Lease,  shall  remain  upon the Leased  Premises at the
expiration or sooner termination of this Lease and become the property of Lessor


                                      -17-
<PAGE>



without  payment  therefor by Lessor,  unless prior to the  termination  of this
Lease,  Lessor shall have given written  notice to Lessee to remove the same, in
which event Lessee, at its expense, will remove such alterations,  improvements,
additions  and/or  fixtures  and  repair and  restore  any and all damage to the
Leased Premises caused by the installation and/or removal thereof.

         17.  SIGNS
              -----

              Lessee may not install any sign  without  Lessor's  prior  written
consent.  All signs shall be in strict  compliance  with the sign  criteria  set
forth in Exhibit "C" attached hereto and made part hereof.  Lessee shall install
all exterior signs for the Leased Premises at the cost and expense of Lessee. No
sign, advertisement or notice shall be inscribed,  painted, affixed or otherwise
displayed on any part of the outside or the inside of the Leased Premises or the
building  of which the Leased  Premises  are a part,  unless  Lessor  shall have
approved the sign, advertisement,  or notice in writing prior to installation of
the same. If any sign,  advertisement,  or notice is exhibited by Lessee without
having first obtained Lessor's approval thereof,  Lessor shall have the right to
remove the same and Lessee shall be liable for any and all expenses  incurred by
Lessor in said  removal.  No signs made of paper and visible from outside of the
Leased Premises shall be allowed in the Leased Premises. No mobile sign, such as
may be affixed to the side of a truck or a trailer or a mobile platform shall be
permitted in the parking area.

         18.  LAWS AND INSURANCE STANDARDS
              ----------------------------

              Lessee shall,  at Lessee's sole expense,  promptly comply in every
respect with all  applicable  laws,  ordinances,  rules and  regulations  of all
federal,  state,  county, and municipal  governments now in force or that may be
enacted in the future,  all applicable  and  enforcement  directions,  rules and
regulations of the fire marshall,  health officer,  building  inspector or other
proper  officers  of  any  governmental  agency  having  jurisdiction,  and  the
applicable standards established from time to time by the National Board of Fire
Underwriters,  the National Fire Protective Association,  or any similar bodies.
Lessee expressly covenants and agrees to indemnify and save Lessor harmless from
any  penalties,  damages or charges  imposed for any violation of the foregoing.
Notwithstanding the foregoing,  Lessee shall not be required to make any changes
or modifications to the Leased Premises, unless (a) the same are required due to
Lessee's specific use and/or occupancy of the Leased Premises,  (b) the same are
required due to structural specifications (beyond building standard) required by
Lessee, or (c) the same relate to repairs, maintenance or other responsibilities
of Lessee under this Lease, e.g., Paragraph 15(a) hereof.

         19.  MECHANIC'S LIENS
              ----------------

              Lessee shall do all things  necessary to prevent the filing of any
mechanics' or other liens against the Leased Premises,  or the land the building
of which the Leased  Premises are part,  by reason of work,  labor,  services or


                                      -18-
<PAGE>



materials  supplied or claimed to have been supplied to Lessee or anyone holding
the Leased premises,  through or under Lessee.  If any lien shall at any time be
filed,  Lessee shall either cause the lien to be discharged of record within ten
(10) days after knowledge of its filing or, if Lessee in its discretion and good
faith determines that the lien should be contested,  shall furnish such security
as may be necessary to prevent the filing of any foreclosure  proceedings during
the pendency of the contest.  If Lessee shall fail to discharge  any lien within
such period or fail to furnish  such  security,  then,  in addition to any other
right or remedy,  Lessor may, but shall not be obligated to,  discharge the same
either by paying the amount  claimed to be due or by procuring  the discharge of
lien by deposit in court or by giving  security or in such other manner as is or
may be  prescribed  by law.  Lessee  shall  repay to Lessor  on demand  all sums
disbursed or deposited by Lessor pursuant to the foregoing provisions, including
the  expenses  and  reasonable  attorneys'  fees  incurred  by  Lessor.  Nothing
contained  in this Lease shall imply that  Lessee has any  authority  or consent
from Lessor to subject Lessor's estate to any mechanics', materialman's or other
lien.

         20.  ASSIGNMENT AND SUBLETTING
              -------------------------

              (a) Lessee shall not assign,  mortgage or encumber any interest in
this Lease or sublet all or any part of the Leased  Premises  without  the prior
written consent of Lessor.  Lessor shall not unreasonably  withhold or delay its
consent to an assignment or subletting of this Lease.

              (b) No permitted assignment or subletting shall release, discharge
or affect the  liabilities  of Lessee as provided for in this Lease,  and Lessee
shall at all times remain  primarily  liable under this Lease.  An assignment by
operation of law shall be deemed a prohibited assignment under this Paragraph.

         21.  INSOLVENCY
              ----------

              Lessor may,  at its option,  declare  this Lessee  terminated  and
reenter  and  resume  possession  of the  Leased  Premises,  if Lessee  shall be
adjudicated  a  bankrupt  or  insolvent,  or if a receiver  or trustee  shall be
appointed for Lessee's business or property,  or if Lessee shall file a petition
in bankruptcy or insolvency, or if a petition or other proceeding shall be filed
by or against Lessee seeking corporate or other  reorganization,  liquidation or
other similar relief or if Lessee shall make an assignment or an arrangement for
the benefit of creditors,  or if an involuntary  petition shall be filed against
Lessee in  bankruptcy or  insolvency  and such  petition  shall not be dismissed
within sixty (60) days.

         22.  REMEDIES CUMULATIVE
              -------------------

              The various rights,  elections and remedies of Lessor contained in
this  Lease  shall  be  cumulative,  and no one of them  shall be  construed  as
exclusive of any of the others,  or of any right,  priority or remedy allowed or
provided for by law.


                                      -19-
<PAGE>



         23.  WAIVER OR DEFAULT
              -----------------

              The waiver by either  party of any default in the  performance  by
the other of any covenant shall not be construed to be a waiver of any preceding
or subsequent  default of the same or any other covenant  contained herein.  The
subsequent  acceptance  of Rent or other  sums by  Lessor  shall not be deemed a
waiver of any  preceding  default  other  than the  failure of Lessee to pay the
particular rental or other sum so accepted.

         24.  HOLDING OVER
              ------------

              If Lessee shall hold  possession of the Leased  Premises after the
end of the term or other termination of this Lease, Leases shall be deemed to be
occupying the Leased Premises as a tenant from month to month, subject to all of
the  conditions,  provisions and obligations of this Lease;  provided,  however,
Lessee  shall be liable for any and all  damages  and  expense  that  Lessor may
sustain by virtue of Lessee's holding over,  including,  but not limited to, any
amount for which Lessor may be liable under,  or as a result of, any other lease
entered into by Lessor for a term  beginning at or after the  expiration  of the
term of this Lease.  Nothing  contained  in this Lease shall be  construed  as a
consent by Lessor to the  occupancy  or  possession  of the Leased  Premises  by
Lessee after the expiration of the term of this Lease. Rather, at the end of the
term of the  Lease,  Lessor  shall be  entitled  to the  benefit  of all laws or
ordinances  relating to the recovery of the  possession  of lands and  tenements
held over by tenants that now may be in force or hereafter  may be enacted,  and
Lessor may proceed under such laws or ordinances,  without notice to Lessee, all
statutory notice requirements being expressly waived by Lessee.

         25.  SURRENDER
              ---------

              Upon the expiration of the term of this Lease,  Lessee immediately
shall surrender the Leased Premises broom-clean and in good order and condition,
ordinary wear and tear excepted.  All of Lessee's  personal property at or about
the Leased Premises (but not permanently  affixed parts of the Leased  Premises)
shall be removed by Lessee at or before the expiration of this Lease or shall be
deemed  abandoned by Lessee.  Any damage to the Leased  Premises  caused by such
removal shall be repaired by Lessee at its own expense.

         26.  DEFAULT
              -------

              (a) If Lessee  fails to pay any Rent or  Additional  Rent when due
and such failure continues for a period of five (5) days after Lessor shall have
made written demand on Lessee for payment, or if Lessee otherwise is at any time
in default under this Lease and continues in such default for a period of thirty
(30) days after  Lessor  shall  have  demanded  in  writing to Lessee  that such
default be cured, or if such latter default is not capable of being cured within


                                      -20-
<PAGE>



a fifteen (15) day period,  such additional time (not to exceed  forty-five (45)
days) as is reasonably necessary to cure such default,  provided Lessee promptly
commences  and  diligently  pursues to cure such  default,  then  Lessor may, at
Lessor's  option,  terminate this Lease (without  releasing Lessee of liability)
and by summary  proceedings or other manner  prescribed by law, reenter and take
possession of the Leased  Premises.  If Lessor  should so terminate  this Lease,
Lessee  shall pay to Lessor as damages,  upon demand,  all expenses  (including,
without limitation,  attorneys' fees) of any proceedings  necessary in order for
Lessor  to  recover  possession  of the  Leased  Premises  and the  expenses  of
reletting  the  Leased  Premises  (including,  without  limitation,   reasonable
attorneys'  fees,  brokerage  commissions,  and the costs of putting  the Leaded
Premises in good order and preparing it for reletting, plus either:

                   (i)   Liquidated damages in an amount equal to the excess, if
any,  of the Rent and  Additional  Rent that  would have been  payable  over the
unexpired  portion of the term of this Lease over the rental value of the Leased
Premises for such unexpired  portion of the term of this Lease, as discounted at
the  then  publicly  declared  prime  rate of the  Federal  Bank  in  Baltimore,
Maryland; or

                   (ii)  Damages  in an amount  to the  excess,  if any,  of the
monthly  Rent and  Additional  Rent over the  monthly  rentals,  if any, if fact
collected by Lessor as the result of a reletting of the Leased  Premises at such
rent and upon such terms as Lessor,  in its sole  discretion,  elects to accept.
Separate  actions may be maintained  each month by Lessor to recover the damages
then due as provided for in this subparagraph (ii) and any such action shall not
prejudice the rights of Lessor to collect damages for any subsequent  month in a
similar proceeding.

              (b)  No re-entry or reletting of the Leased  Premises,  whether or
not the term of such reletting  extends beyond the term of this Lease,  shall be
construed  as an  election  by Lessor to: (i) accept a  surrender  of the Leased
Premises, or (ii) release Lessee of any of its obligations under this Lease.

              (c)  Should Lessor,  pursuant to its rights under  Paragraph 26(a)
hereof,  elect to terminate  this Lease and reenter and take  possession  of the
Leased Premises,  Lessor shall use commercially  reasonable efforts,  under then
prevailing circumstances, to relet the Leased Premises.

         27.  ACCESS TO LEASED PREMISES
              -------------------------

              (a)  Lessor and its  designees  shall have the right  (subject  to
being accompanied by Lessee's  representative at all times for security reasons)
to enter  upon the  Leased  Premises  at all  reasonable  hours,  after 24 hours
notice,  (and in  emergencies,  at all times):  (i) to inspect the same; (ii) to
make repairs,  additions,  or alterations to the Leased Premises or the building
in which the same are located or any property  owned or  controlled by Landlord;
(iii) to  exhibit  the  Leased  Premises  to any  prospective  buyer,  lessee or
mortgagee or their respective agents or representatives; and (iv) for any lawful
purpose.


                                      -21-
<PAGE>



              (b)  For a period  commencing three (3) months prior to the end of
the term,  Lessor may have reasonable  access to the Premises for the purpose of
exhibiting  the same to  prospective  tenants and to post any "For Rent" or "For
Lease" signs upon the Leased Premises.

         28.  SUBORDINATION AND ATTORNMENT
              ----------------------------

              (a)  This  Lease is  subject  and  subordinate  to the lien of all
present  and  future  mortgages  and/or  deeds of trust  encumbering  the Leased
Premises,  all present and future advances under such mortgages  and/or deeds of
trust, and all renewals, extensions,  modifications,  recastings or refinancings
of such  mortgages  and/or deeds of trust.  Lessee agrees that, in the event any
proceedings are brought under or for the foreclosure of any such mortgage and/or
deed of trust,  Lessee shall, if requested to do so by the beneficiary  under or
holder of such mortgage  and/or deed of trust or by any successor in interest to
such beneficiary or holder, automatically become the lessee of such beneficiary,
holder  or  successor  in  interest  and  shall  automatically  attorn  to  such
beneficiary, holder and/or successor in interest and recognize such beneficiary,
holder  and/or  successor  in  interest  as the  Lessor  under  this  Lease.  In
confirmation of such attornment, however, Lessee shall, at the request of Lessor
or any  beneficiary,  holder or  successor  in  interest,  promptly  execute any
requisite or  appropriate  certificate or other document for the benefit of such
beneficiary, holder and/or successor in interest.

              (b)  In the event that,  after the date of this Lease, a bona fide
loan shall be made by an insurance company, savings bank, commercial bank, trust
company, or other lender and secured by a mortgage or deed of trust constituting
a lien  against  any  portion  of the  Leased  Premises  and said  lender  shall
complete,   execute   and   acknowledge   a   subordination,   attornment,   and
non-disturbance agreement, then and in that event, Lessee shall subordinate this
Lease to said mortgage or deed of trust by executing and  acknowledging the said
subordination, attornment and non-disturbance agreement.

              (c)  Upon any assignment or  termination  of Lessor's  interest in
the Leased Premises,  Lessee shall,  upon request,  attorn in writing to the new
owner of the Leased  Premises and shall pay to the new owner all rents and other
monies  required to be paid and perform all of the other  obligations  of Lessee
under this  Lease.  Following  any sale by Lessor of the  property  of which the
Leased  Premises are a part, all  obligations to the assigning  Lessor to Lessee
shall cease and  termination  and Lessee shall look solely to the  successor for
the performance of Lessor's duties hereunder.

              (d)  Notwithstanding  the  foregoing,  this  Lease  shall  not  be
terminated so long as Lessee is not in default of any provisions in this Lease.

              (e)  Lessor shall,  within fifteen (15) days after the date hereof
(or prior to the effective date of any encumbrance  mentioned in this Section 28
created after the date hereof)  obtain from the holder of any such  encumbrance,



                                      -22-
<PAGE>



an agreement whereby if such holder or any successor in interest shall come into
possession  of the  Leased  Premises,  or any part  thereof,  by  dispossession,
foreclosure or otherwise,  or shall become the owner of such  property,  or take
over the rights of Lessor to such  property,  said holder  shall not disturb the
possession, use or enjoyment of the Leased Premises by Lessee, its successors or
assigns,  nor  disaffirm  this  Lease  or  Lessee's  rights  or  estate  granted
hereunder,  so long as Lessee performs all of its obligations in accordance with
the terms of this Lease.

         29.  RIGHT TO CURE DEFAULTS
              ----------------------

              (a)  If  Lessee  shall  fail  to  comply  fully  with  any  of its
obligations  under this Lease,  then, in addition to Lessor's other rights,  but
not the  duty,  to cure  such  breach  at  Lessee's  expense.  Lessee  agrees to
reimburse  Lessor,  within fifteen (15) days after Lessor submits a statement of
the amount due, as  Additional  Rent,  for all expenses  incurred by Lessor as a
result of any efforts made by Lessor to cure any such breach.

              (b)  If  Lessor  shall  fail  to  comply  fully  with  any  of its
obligations  under this Lease,  then,  in addition to Lessee's  other rights and
remedies under this Lease at law and in equity, Lessee shall have the right, but
not the duty,  to cure such breach at Lessor's  expense;  provided that prior to
the  exercise of such right to cure,  Lessee  shall give Lessor  written  notice
specifying  the nature of the breach and Lessor  shall be  entitled  to ten (10)
days  after  receipt of such  notice  within  which to cure said  breach or such
additional  time as may be necessary if such breach is not  susceptible  to cure
within said ten (10) days,  in which case Lessor  shall  commence to cure within
said ten (10) day period. Lessor agrees to reimburse Lessee, within fifteen (15)
days after  Lessee  submits a  statement  of the amount  due,  for all  expenses
incurred by Lessee as a result of any efforts by Lessee to cure any such breach.
If Lessor fails to reimburse  Lessee as aforesaid,  Lessee may offset the amount
due against the  payments of Rent  becoming  due  hereunder  unless  Lessor give
written  notice of dispute  within said  fifteen  (15) day period  either to the
existence of any default or the  reasonableness  of the amount expended to cure.
In the event such notice of dispute is given, the provisions of subparagraph (c)
shall govern. The right to setoff against Rent shall be subordinate to and there
shall be no setoff  against the holder of any  mortgages or deed of trust or any
purchaser  at  foreclosure  or deed in lieu thereof on all or any portion of the
Leased  Premises.  The amount of all setoffs shall be limited to the  cumulative
sum of One  Hundred  Thousand  Dollars  ($100,000.00).  

              (c)  If  Lessor  has  given  notice  of  dispute  as  provided  in
subparagraph (b), Lessee may have the issues of whether the Lessor is in default
of  its  obligations  or  the  reasonableness  of  the  amount  of  expenditures
determined by arbitration.  Pending the results of such arbitration, there shall
be no setoff. In the event the arbitrators determine that Lessor was in default,
Lessor  shall pay all costs of  arbitration  and Lessee  shall have the right to
offset  all of its costs and  expenses  of  remedying  such  default  (including
unreimbursed costs of the arbitration  proceeding)  against the payments of Rent
becoming due hereunder, subject to the limitations set forth in subparagraph (b)
above. If the arbitrators  determine that Lessor was not in default, then Lessee
will pay all of the arbitration.


                                      -23-
<PAGE>



              (d)  If Lessor is determined  to be in default in its  obligations
under  Paragraph  15(c) of this Lease and Lessee  shall  remedy such  default in
accordance with the preceding paragraph,  Lessee shall be entitled to offset one
hundred  fifteen  percent  (115%) of the costs and  expenses of  remedying  such
default, with the additional fifteen percent (15%) being to reimburse Lessee for
its overhead.

         30.  BROKERAGE
              ---------

              Lessor  hereby  acknowledges  that  THE  MICHAEL  COMPANIES,  INC.
("Broker") has served as Lessor's agent in connection with this Lease and agrees
to pay said Broker a commission as per a separate  agreement  between Lessor and
Broker.  Lessor warrants to Lessee and Lessee warrants to Lessor that it has not
dealt with any other  broker or real estate agent or finder in  connection  with
this Lease and that, except for the aforesaid  commission  payable to Broker, no
right or claim for  commission  or other  compensation  has been  created by its
actions with respect to this Lease.  Lessor and Lessee shall  indemnify and hold
each other harmless against all loss, liability or expense, including reasonable
attorney's fees and litigation costs, incurred by the other to the extent one or
the other is shown to be in breach of the foregoing warranties.

         31.  EFFECT OF CONVEYANCE
              --------------------

              If during the term of this Lease  Lessor sells its interest in the
Leased  Premises or this Lease,  then from and after the effective  date of such
sale,  Lessor  shall  be  released  and  discharged  from  any and  all  further
obligations and responsibilities  under this Lease except those already accrued.
Any such sale  shall be  subject to this  Lease and  Lessor  shall  require  any
purchaser to acknowledge the existence of Lessee's tenancy.

         32.  INTERPRETATION
              --------------

              The captions by which the  paragraphs of this Lease are identified
are for  convenience  only and shall have no effect upon the  interpretation  of
this Lease. Whenever the context so requires,  the singular number shall include
the plural,  and plural shall refer to the singular and the neuter  gender shall
include the masculine and feminine genders. If any provision of this Lease shall
be held to be unenforceable by a court, the remaining provisions shall remain in
effect and shall in no way be impaired.

         33.  ENTIRE INSTRUMENT
              -----------------

              All of the agreements previously and contemporaneously made by the
parties are  contained  in this Lease,  and this Lease cannot be modified in any
respect except by a writing executed by Lessor and Lessee.


                                      -24-
<PAGE>



         34.  ESTOPPEL CERTIFICATES
              ---------------------

              Recognizing  that both  parties may find it necessary to establish
to third parties, such as accountants,  banks,  mortgagees or the like, the then
current status of performance hereunder, either party, on the written request of
one to the  other  made  from  time to time,  will  promptly  furnish  a written
certificate  on the status of any matter  pertaining  to this Lease in such form
and substances as may from time to time be reasonably required.

         35.  NOTICES
              -------

              Any notices and other  communications  required or permitted to be
given by either  party to the other  shall be in writing  and shall be deemed to
have been served when hand  delivered  or, if the United States Mail is used, on
the second business day after the notice is deposited in the United States Mail,
postage prepaid, registered or certified mail, or by overnight delivery service,
and addressed to the parties as follows:

         To Lessee:             Jacques R. Rubin
                                President
                                Bio Science Contract Product Corp.
                                4406 Bel Pre Road
                                Rockville, Maryland  20853

         To Lessor:             Muirkirk Manor Associates Limited Partnership
                                c/o The Anastasi Stephens Group, Inc.
                                4483 Forbes Boulevard
                                Lanham, Maryland   20706

Either party,  by written  notice to the other,  may change its address to which
notices are to be sent.

         36.  WAIVER
              ------

              Any waiver of either  Lessor or Lessee of any  default,  breach or
failure by the other to comply with any term,  condition,  or  provision of this
Lease shall not constitute a waiver of any other  default,  breach or failure by
such  defaulting  party.  No covenant,  term or condition of this Lease shall be
deemed to have been waived by either  party unless such waiver be in writing and
signed by the party to be charged therewith.

         37.  QUIET ENJOYMENT
              ---------------

              So  long as  Lessee  is not in  default  beyond  applicable  grace
periods,  Lessee shall have peaceful and quiet use and  possession of the Leased
Premises  without  hindrance  on the part of Lessor or any person  claiming  by,
through or under Lessor.


                                      -25-
<PAGE>



         38.  RECORDING THIS LEASE
              --------------------

              Lessee may not record  either this Lease nor a memorandum  thereof
among or in any public records without Lessor's prior written consent.

         39.  GOVERNING LAW
              -------------

              All questions with respect to  construction  of this Lease and the
rights and liabilities of the parties shall be determined in accordance with the
laws of the State of Maryland.

         40.  BENEFIT
              -------

              Subject to the restrictions on assignment and subletting set forth
in Paragraph 20, the  covenants,  terms and conditions of this Lease shall inure
to the  benefit of and be binding  upon  Lessor and Lessee and their  respective
successors and assigns.

         41.  REASONABLE CONSENT
              ------------------

              Wherever in this Lease  Lessor or Lessee is required to obtain the
consent or  approval of the other,  it is agreed  that such  consent or approval
shall not be unreasonably withheld or delayed.

         42.  TIME OF ESSENCE
              ---------------

              Time is of the  essence  in the  performance  of all of Lessor and
Lessee's obligations under this Lease.

                  (See Lease Addendum for Paragraphs 43 and 44)



                                      -26-
<PAGE>



              IN WITNESS  WHEREOF,  the parties have  executed this Lease on the
day and year first above written.


WITNESS:                                 LESSOR:

                                         MUIRKIRK MANOR ASSOCIATES
                                         LIMITED PARTNERSHIP,
                                         a Maryland limited partnership

                                         By: THE ANASTASI STEPHENS GROUP, INC.
                                               its general partner


 /s/ Richelle J. Darnell                      By:   /s/ Joseph Anastasi   (Seal)
-------------------------                           ----------------------------


WITNESS:                                 LESSEE:

                                         BIO SCIENCE CONTRACT PRODUCTION CORP.
                                         a Maryland corporation


 /s/ Richelle J. Darnell                      By: /s/ Jacques R. Rubin
------------------------                          ---------------------


                                      -27-
<PAGE>




                              EXHIBIT "A" (PART II)

                                 LEASE ADDENDUM
                                 --------------

                                  (PARK PLACE)


         THIS  LEASE  ADDENDUM  made as of the 28th day of  December,  1990,  is
attached  to and made  part of that  certain  Lease of even date  herewith  (the
"Lease")  by and  between  MUIRKIRK  MANOR  ASSOCIATES  LIMITED  PARTNERSHIP,  a
Maryland limited partnership  ("Lessor"),  and BIO SCIENCE CONTRACT  PRODUCTDION
CORP., a Maryland corporation ("Lessee").

                              W I T N E S S E T H:
                              - - - - - - - - - -

         WHEREAS,  LESSOR and LESSEE  have  agreed to amend,  supplement  and/or
modify the Lease as herein provided, Lessor and Lessee hereby agree as follows:

         2.   TERM - OPTION
              -------------

              Lessee, at its option,  shall have the right to extend the Term of
this Lease on the same terms and conditions as the original term thereof, except
as otherwise  provided in this  Addendum with respect to the amount of Base Rent
during the respective extension period, for two (2) additional consecutive terms
of five (5) years each (the "Extension  Periods") subject to the satisfaction of
the following conditions:

              (i)    Lessee's  option  to  extend  the  Lease  for  each  of the
Extension Periods shall be exercisable only by written notice to Leasor at least
ninety (90) days prior to the  commencement  date of each Extension  Period.  If
Lessee does not give Lessor written notice as aforesaid,  Lessee shall be deemed
to have not exercised its respective extension option.

              (ii)   At  the  time  of   exercise  of  the  option  and  at  the
commencement of each Extension Period,  Lessee shall not be in default under the
Lease beyond any applicable grace period.

              (iii)  Upon  exercising  the  option,  the Base  Rent  will be the
product  obtained by  multiplying  the Base Rent for the  immediately  preceding
Lease Year by one hundred four percent (104%).

         3.   RENT
              ----

              For  months  1,  2,  3 and 4 of  the  first  base  year,  Lessee's
obligation  to pay 1/2 of the monthly base rent is hereby  waived.  It is agreed
that Common  Area  Maintenance  charges and  Additional  Rent,  if any,  will be
collected on the first day of occupancy, pursuant to Paragraph 8.(c).


                                      -28-
<PAGE>



         43.  LESSEE IMPROVEMENTS
              -------------------

              (d)  The  term  "force  majeure"  as used  herein  shall  include,
without  limitation,  the  following:  acts of God,  strikes,  lockouts or other
industrial  disturbances;  acts of  public  enemies;  orders  of any kind of the
government of the United States or of the State in which the Leased Premises are
located or of any subdivision  thereof or any local government,  or any of their
departments,  agencies  or  officials,  or  any  civil  or  military  authority;
insurrections;  riots;  epidemics;  landslides;  lightning;  earthquakes;  fire;
hurricanes; storms; floods; washouts; droughts; arrests; restraint of government
and people; civil disturbances;  explosions;  breakage or accident to machinery,
transmission  pipes or canals;  partial or entire  failure of utilities;  or any
other cause or event not reasonably within the control of the Lessee.

              (e)  Tenant  requires  that  certain  improvements  be made to the
Leased  Premises  for its use.  The parties have agreed on the scope of the work
(the "Work") to be done and have  approved  construction  drawings for the work.
The  Work  is to be  done  under  a  construction  contract  (the  "Construction
Contract") between Landlord and Barber Construction Corporation  ("Contractor").
The  Construction  Contract has been  approved by Landlord and Tenant.  Landlord
will be  responsible  for the  supervision  and timely  completion  of the work,
regardless of the performance of the Contractor.

                   The Work is to be completed no later than March 1, 1991 for a
contract  price of  $231,148.70  of which  Landlord will pay $200,000 and Tenant
will pay  $31,148.70,  provided  that the  amount to be paid by  Tenant  will be
reduced by any amount that the contract  price is reduced for any reason.  Prior
to commencement  of the Work as provided in the  Construction  Contract,  Tenant
will pay its  contribution  of  $31,138.70  in  escrow  with C.  Lawrence  Wisor
("Escrow  Agent"),  as  escrow  agent,  to be paid by the  Escrow  Agent  to the
Contractor as the terms of the Construction  Contract provide after the Landlord
has paid all of its $200,000 contribution, less retainage, to the Contractor.

                   Any changes to the approved  construction  drawings  shall be
signed or  initialed  by  Landlord  and  Tenant and  change  orders  made to the
Construction  Contract.  Tenant  agrees to pay to the Escrow  Agent the contract
price for any change orders at the time such change  orders are signed.  Payment
is to be made by the Escrow Agent to the Contractor  upon submission of invoices
approved by the Landlord.  Tenant shall be responsible to Landlord for any delay
in completion of the work as a result of such changes.  Neither the commencement
date of the Lease nor the commencement of rents due shall be deferred because of
any such  changes  but will be  deferred  if the  Work is not  completed  by the
completion  date given  above for any  reason  other than the effect of any such
change order.


                                      -29-
<PAGE>



         44.  GROUND LEASE
              ------------ 

              Lessor has leasehold ownership of the project known as Park Place,
of which the Leased  Premises  are a part,  under a long-term  ground lease (the
"Ground  Lease"),  the term of which  exceeds  the  initial  term and  extension
periods of this Lease.  Lessor represents that the Ground Lease is in full force
and effect and that there are no defaults thereunder. Lessor further agrees that
so long as this Lease in effect,  it will timely perform all of its  obligations
under the Ground Lease.

              Lessor  shall,  within  fifteen  (15) days  after the date  hereof
obtain  from the  Lessor  (the  "Ground  Lessor")  under the  Ground  Lease,  an
agreement  whereby if the Ground Lessor  terminates the Ground Lease, the Ground
Lessor shall not disturb the possession, use or enjoyment of the Leased Premises
by Lessee,  its  successors  or assigns,  nor  disaffirm  this Lease or Lessee's
rights or  estate  granted  hereunder,  so long as  Lessee  performs  all of its
obligations in accordance with the terms of this Lease.

         IN WITNESS  WHEREOF,  the parties have executed this Lease  Addendum on
the day and year first above written.


ATTEST:                              LESSOR:

                                     MUIRKIRK MANOR ASSOCIATES
                                     LIMITED PARTNERSHIP,
                                     a Maryland limited partnership

                                     By: THE ANASTASI STEPHENS GROUP, INC.
                                            its general partner


/s/ Richelle J. Darnell                  By: /s/ Joseph Anastasi         (Seal)
-------------------------                    ----------------------------------


                                     LESSEE:

                                     BIO SCIENCE CONTRACT PRODUCTION CORP.
                                     a Maryland corporation


/s/ Richelle J. Darnell                  By: /s/ Jacques R. Rubin
-------------------------                    ---------------------


                                      -30-
<PAGE>




                                   EXHIBIT "B"

                                  SECOND LEASE
                                  ------------


                                      LEASE
                                      -----

                                  (PARK PLACE)


         THIS LEASE, made as of this 12th day of November,  1991, by and between
MUIRKIRK MANOR ASSOCIATES LIMITED  PARTNERSHIP,  a Maryland Limited  partnership
("Lessor"),  and BIO SCIENCE CONTRACT PRODUCTION CORP., a Maryland  corporation,
("Lessee").

                              W I T N E S S E T H:
                              - - - - - - - - - -

         That in  consideration  of the rent and mutual covenants and agreements
contained  herein,  and intending to be legally bound hereby,  Lessor and Lessee
agree as follows:


         1.   DEMISED PREMISES
              ----------------

              The  Lessor  leases  to the  Lessee  all  of  that  certain  space
described  as  Suite  No.  270,  280,  9000  Virginia  Manor  Road,   containing
approximately  12,731 square feet of gross  leasable area, as is outlined in red
on the piat  attached  to and  made a part of this  Lease  as  Exhibit  "A" (the
"Leased Premises"), and located in Park Place, Prince George's County, Maryland.
Lessor shall  construct and complete the Leased  Premises in compliance with the
plans and  specifications set forth in Exhibit "B" attached hereto and made part
hereof. "Delivery of Possession" of the Lease Premises by Lessor to Lessee shall
be deemed to have been made when  Lessor's  architect  certifies in writing that
construction of the Leased Premises shall have been completed.

         2.   TERM
              ----

              The term (the  "Term") of this  Lease  shall be for a term of nine
(9) years, and two (2) months,  commencing on the 1st day of January, 1992, (the
"Commencement Date") and shall expire on the last day of February,  2001. If the
Term of the Lease does not begin on the date specified  herein for reasons other
than the  fault of  Lessee,  then the  expiration  date  shall be moved  for the
commensurate amount of the delay and the rent shall be prorated accordingly.  If
the term  commences  or ends in  mid-month,  the  rent  payable  for that  month
(including,  without limitation,  Additional Rent) shall be prorated and paid on
the date of commencement or termination.


                                      -31-
<PAGE>



        3.    RENT
              ----

              (a)  The rent (the "Base Rent") shall be:

                 Year                      Square Foot Rate
                 ----                      -----------------

                   1                            $ 9.06
                   2                            $ 9.39
                   3                            $ 9.77
                   4                           $ 10.16
                   5                           $ 10.57
                   6                           $ 10.99
                   7                           $ 11.43
                   8                           $ 11.89
                   9                           $ 12.36

The term "Lease Year" shall mean each twelve (12) month  period  during the term
of this  Lease  commencing  on the  Commencement  Date.  The Base Rent  shall be
payable,  in  advance,  in  equal  monthly   installments,   the  first  monthly
installment to be due and payable on the  Commencement  Date and each subsequent
monthly  installment  to be due and  payable  on the first day of each and every
month thereafter during the term of this Lease.

              (b)  All moneys  payable by Lessee  under the terms of this Lease,
other than Base Rent, as adjusted from time to time, shall be deemed "Additional
Rent."

              (c)  Lessee  shall make all  payments of Base Rent and  Additional
Rent on a  timely  basis,  without  demand  and  without  deduction,  setoff  or
counterclaim,  except as  expressly  permitted in Paragraph  29(b)  hereof.  All
payments  of Rent and  Additional  Rent  shall be made by good and valid  check,
payable to The Anastasi  Stephens Group,  Inc.,  agent,  4483 Forbes  Boulevard,
Lanham,  Maryland  20706,  or to such other  party or to such  other  address as
Lessor may designate  from time to time by written  notice to Lessee.  If Lessor
shall at any time or times  accept Base Rent or  Additional  Rent after it shall
become due and payable,  such acceptance  shall not excuse delay upon subsequent
occasions, or constitute,  or be construed as, a waive of any or all of Lessor's
rights  hereunder.  If any payment of Base Rent or  Additional  Rent is not made
within  ten (10) days of when due,  a late  charge of five  percent  (5%) of the
amount of such payment shall be imposed, Lessor shall be entitled to require the
payment of Base Rent and Additional Rent by certified check if the check for any
payment by Lessee shall be dishonored by its Bank.

              (d)  Except  for the  obligations  of Lessor  expressly  set forth
herein,  this  Lease is a "net  lease" and Lessor  shall  receive  the Base Rent
hereinabove  provided as net income from the Leased Premises,  not diminished by
any  imposition  of any expenses or charges  required to be paid to maintain and
carry the Leased  Premises or to continue the  ownership  of Lessor,  other than
payments  under any mortgages now existing or hereafter  created by Lessor,  and
Lessor is not and shall not be  required  to render any  services of any kind to
Lessee.


                                      -32-
<PAGE>



         4.   SECURITY DEPOSIT
              ----------------

              (a)  Lessee has,  simultaneously with the execution of this Lease,
deposited  with Lessor,  in cash or by check subject to  collection,  the sum of
eight  thousand and 00/100  ($8,000.00).  Said deposit shall be held as security
for the faithful performance by Lessee of the terms,  covenants,  provisions and
conditions  of this  Lease.  It is agreed that in the event  Lessee  defaults in
respect to any of the terms, covenants, provisions and conditions of this Lease,
including (but not limited to) the payment of Base Rent or Additional  Rent, and
fails to cure any such defaults within applicable grace periods, Lessor may use,
apply or  appropriate  the whole or any part of the security so deposited to the
extent  required for the payment of any Base Rent or Additional  Rent or for the
curing of any  defaults by Lessee  hereunder  pursuant to  Paragraph  29 hereof;
provided,  however,  that no such  use,  application,  or  appropriation  of the
deposit shall be deemed to relieve  Lessee of any breach of this Lease and shall
be in addition to other remedies under this Lease.

              (b)  Should  the  entire   deposit  or  any  portion   thereof  be
appropriated and applied by Lessor under the foregoing  provisions,  then Lessee
shall (upon the written demand of Lessor) forthwith remit to Lessor a sufficient
amount in cash to restore  said  security to the  original  sum  deposited,  and
Lessee's  failure  to do so within ten (10) days  after  receipt of such  demand
shall itself constitute an event of default under this Lease.

              (c)  The security deposit (less any amounts applied as provided in
subsection  (a) above) shall be returned to Lessee within thirty (30) days after
the date  fixed as the end of the Term of this  Lease  and  delivery  of  entire
possession of the Leased Premises to Lessor.

              (d)  In the event of a sale, leasing or other transfer of the land
and building of which the Leased  Premises  forms a part,  Lessor shall have the
right to transfer the security and be released by Lessee from all  liability for
the return of such security deposit.  Lessee shall look to the new Lessor solely
for the return of said  deposit.  The  provisions of this  Paragraph  4(d) shall
apply to every  transfer or  assignment  made of the  security  deposit to a new
Lessor.

              (e)  Lessee  covenants  that it will not  assign  or  encumber  or
attempt to assign to encumber  the  security  deposited  herein and that neither
Lessor  nor its  successors  or assigns  shall be bound by any such  assignment,
encumbrance, attempted assignment or attempted encumbrance.

              (f)  Lessee  shall not be entitled to any interest on the security
deposit, and such funds need not be segregated or held as escrow by Lessor.


                                      -33-
<PAGE>


              (g)  It is expressly  understood  and agreed that, in the event of
any  termination  of this  Lease or  re-entry  upon or  reletting  of the Leased
Premises on account of any default on the part of Lessee under this Lease, then,
and in such event, the deposit shall be retained and be subject to appropriation
by Lessor  until this  Lease  would,  by its terms,  have  expired  absent  such
default.

         5.   USE
              ---

              Lessee  will use and  occupy the  Leased  Premises  solely for the
purpose of Offices and operation of a vaccine research and production  facility,
The Leased  Premises  may not be used for any other  purpose  without  the prior
written consent of Lessor, which consent shall not be unreasonably withheld. The
Leased  Premises shall not be used for the storage,  distribution or sale of any
pornographic  or  "adult  rated"  materials.  Lessee  shall  not use the  Leased
Premises for any purpose or activity which is noxious or unreasonably  offensive
because of the emission of noise, smoke, dust,  vibration or odors. Tenant shall
not use the plumbing  facilities for any purpose injurious to same or dispose of
any  garbage or any other  foreign  substance  therein,  nor place a load on any
floor in the Leased  Premises  exceeding  the floor load of 250 per square  foot
which such floor was designed to carry, nor install,  operate and/or maintain in
the Leased  Premises and heavy  equipment  which could cause injury to the Lease
Premises,  nor  install,  operate  and/or  maintain in the Leased  Premises  any
electrical  equipment which will overload the electrical system therein,  or any
part hereof,  beyond its capacity for proper and safe operation as determined by
the Lessor or which does not bear underwriter's  approval.  Lessee shall not use
the Leased  Premises in any manner or for any purpose  which  violates any rule,
regulation, law, ordinance, or requirements of any governmental agency.

         6.   TAXES
              -----

              (a)  As  additional  rent  hereunder,  at least  thirty  (30) days
before  any fine,  penalty  or  interest  or cost may be added  thereto  for the
non-payment  thereof (or sooner if elsewhere herein required),  Lessee shall pay
throughout  the term of this Lease all  levies,  taxes,  assessments,  water and
sewer  rents and  charges,  liens,  charges for public  utilities  and all other
charges,  imposts  or burdens of  whatsoever  kind and nature  which at any time
during the term of this Lease may be assessed or imposed by any  federal,  state
or  municipal  government  or  public  authority,  or under  any law,  ordinance
regulation  thereof or pursuant to any recorded  covenants or agreements (all of
which are hereinafter referred to as "Impositions"), upon or with respect to the
Leased Premises,  any improvements  made thereto,  or this Lease.  Additionally,
Lessee shall pay a  proportionate  share of any Imposition  which is not imposed
upon the Leased Premises as a separate entity but which is imposed upon the land
or the  building  or upon the  appurtenances,  leases,  rents,  transactions  or
documents  relating  to the lot or the  building.  Provided,  however,  that any
Imposition  shall be apportioned for the first and last fiscal tax years covered
by the term hereof.  "Impositions" shall include, but not be limited to, any and
all governmental or  quasi-governmental  levies,  fees,  assessments,  taxes and
charges,  general  and  special,   ordinary  and  extraordinary,   foreseen  and
unforeseen,  of any kind and nature  whatsoever,  with  respect to such land and
building  (excluding  taxes paid on Lessor's  income but including  sales tax or
excise tax imposed by any  governmental  authority upon the Base Rent payable by
Lessee hereunder).


                                      -34-
<PAGE>



              (b)  Notwithstanding  the foregoing  provisions of this Article 6,
Lessor shall have the right,  at its option,  to require Lessee to pay to Lessor
or to any  mortgagee,  at the time when the monthly  installment of Base Rent is
payable,  an amount equal to  one-twelfth  (1/12) of the annual  Impositions  as
estimated by Lessor. If Lessor elects to have Lessee make such payments,  Lessee
also  shall  pay to Lessor  or to such  mortgagee,  as the case may be, at least
thirty (30) days before any fine, penalty, interest or cost may be added thereto
for the non-payment  thereof,  the amount by which the Impositions  becoming due
exceed the monthly  installment  payments on account thereof  previously made by
Lessee.  Should  Lessee's  monthly  installment  payments on account of Lessee's
share of Impositions for any tax year exceed the actual amount of Lessee's share
of such  Impositions,  the excess  amount  shall be  credited  against  Lessee's
installments for Impositions thereafter becoming due. The amounts paid by Lessee
pursuant to this  paragraph (b) shall be used to pay the  Impositions,  but such
amounts  shall not be deemed to be trust funds and no interest  shall be payable
thereon.

              (c)  During any part of the Term of this Lease which shall be less
than a full tax  fiscal  year,  any Taxes  shall be pro  rated on a daily  basis
between  the  parties,  to the end that Lessee only shall pay its share of Taxes
attributable to the portion of the tax fiscal years occurring within the term of
this Lease.

              (d)  Lessee shall pay  promptly,  and when due,  all taxes,  fees,
licenses,  assessments  and other charges levied or imposed upon the business of
the  Tenant  or upon  any  fixtures,  furnishings  or  equipment  in the  Leased
Premises.

              (e)  If due to a future change in the method of taxation or in the
taxing authority,  a franchise,  gross receipts,  transit,  rent or other tax or
other  governmental  imposition,  however  designated,  shall be levied  against
Lessor in  substitution  (in whole or in part)  for,  or in  addition  to,  said
"Impositions"  as  currently  defined),  then such  franchise,  gross  receipts,
transit,  rent or other tax or  governmental  impositions  shall be deemed to be
included within the definition of "Impositions"  for the purposes of this Lease.
The term  "Impositions"  also  includes  all costs  reasonably  incurred  in any
proceeding brought by Lessor to reduce said Taxes.


              (f)  Lessor may  institute  any  proceedings  with  respect to the
assessed valuation of Park Place or any part thereof, and Lessee shall cooperate
with, and participate in, any and all such  proceedings.  If, after Lessee shall
have made the required payment of Taxes hereunder, Lessor shall receive a refund
of any portion thereof,  then, within thirty (30) days after Lessor's receipt of
such refund, Lessor shall pay to Lessee Lessee's pro rata share of the amount of
the  refund,  less all  costs  and  expenses  (including,  but not  limited  to,
attorneys' and appraiser'  fees) expended for incurred in obtaining such refund.
Lessee may not institute any proceedings with respect to the assessed  valuation
of Park Place or any part thereof.


                                      -35-
<PAGE>



         7.   UTILITIES
              ---------

              Starting with the Commencement Date and continuing  throughout the
Term of the Lease,  Lessee shall be solely responsible for and shall pay, as and
when the same  become due and payable and as  hereinafter  provided,  all rents,
rates, costs and charges for water services,  sewer service,  electricity,  gas,
heat, steam, power, telephone (and other communication  services), and any other
utilities or services  rendered or supplied to, upon or in  connection  with, or
used or consumed  within or in  servicing,  the Leased  Premises,  and all other
utility costs and expenses involved in the use of the Leased Premises throughout
the term of this  Lease,  and Lessee  shall  indemnify  Lessor  and save  Lessor
harmless  against  any  costs  liability  or  damages  on such  account.  Unless
otherwise  agreed in writing by Lessor or Lessee,  Lessee  shall,  promptly upon
Delivery of Possession of the Leased  Premises and at Lessee's own expense,  pay
for the  installation of separate meters for all utilities  servicing the Leased
Premises  and place said meters and  related  utility  accounts in Lessee's  own
name.  Lessee shall pay all separately  metered charges to the respective public
utility companies.  With respect to each utility which is not separately metered
for the Leased Premises,  Lessee shall pay Lessor, as Additional Rent,  Lessee's
proportionate  share of the total cost and fees therefore  attributable to those
areas of the warehouse/office buildings which are not separately metered.

         8.   COMMON AREA MAINTENANCE
              -----------------------

              (a)  Subject to the  provisions  of this Lease,  Lessor  grants to
Lessee, its employees, agents, customers and invitees during the Term hereof the
non-exclusive use, in common with Lessor and other tenants and occupants of Park
Place and their  respective  employees,  agents,  customers  and invitees and in
common  with such  others  as Lessor  may  designate  from time to time,  of all
non-allocated  parking  areas  within Park Place for  pedestrian  and  vehicular
ingress and egress and the accommodation and parking areas within Park Place for
pedestrian and vehicular  ingress and egress and the  accommodation  and parking
automobiles as required by the Lessee in conducting  normal business  activities
of Lessee within the Leased  Premises.  Lessor reserves the right,  however,  to
designate certain portions of the parking areas within Park Place for parking of
trucks,  vans, and other vehicles,  and to designate for the specific account of
Lessee,  or other  tenants  in Park  Place,  specific  parking  areas or  spaces
constructed with Park Place. Notwithstanding anything contained in this Lease to
the contrary, Lessor shall have the right, at any time and from time to time, to
change the size, location and nature of the parking areas (so long as the number
of parking  spaces is not reduced)  and/or other common areas within Park Place.
All parking areas and related  facilities which may be furnished by Lessor in or
near the Leased Premises, including employee parking areas, truck way or ways,


                                      -36-
<PAGE>



loading docks, pedestrian sidewalks and ramps, landscaped areas, and other areas
and improvements  which may be provided by Lessor for the general use, in common
with Lessor and other tenants, and their respective employees, agents, customers
and  invitees,  shall  at all  time be  subject  to the  exclusive  control  and
management  of Lessor,  and Lessor shall have the right,  from time to time,  to
establish,  modify and enforce  reasonable rules and regulations with respect to
all parking areas and other  facilities and areas  mentioned in this  paragraph.
Lessee agrees to abide by and conform with all such rules and  regulations  upon
notice thereof and to cause its employees,  agents, customers and invitees to do
the same.  Lessor shall have no liability to Lessee for use of the parking areas
by Lessor or other  tenants  and  occupants  of Park Place and their  respective
employees, agents, customers, or other third parties. No provision of this Lease
shall be  construed  as a demise to Lessee of the  parking  or any other  common
area) within Park Place.  If any repairs  (excluding  repairs caused by Lessee's
normal  use) to the  parking  or  other  common  areas  within  Park  Place  are
necessitated  by reason  of any act or  omission  by  Lessee  or its  employees,
agents, customers or invitees, then, if Lessor chooses to do so, Lessor may make
such repairs and Lessee shall promptly upon demand reimburse Lessor for the full
costs to the extent same are not covered by Lessor's  insurance,  or at Lessor's
option,  Lessor may notify Lessee of the necessity for such repairs, and Lessee,
at its cost and expense,  shall,  with due  diligence,  commence and complete to
Lessor's  satisfaction  the repairs within ten (10) days of Lessee's  receipt of
such notice.

              (b)  "Common  Area  Charges"  means all of the costs and  expenses
which are incurred by Lessor with respect to operation, management,  maintenance
and security of the building  including the parking and other designated  common
areas in Park Place and the exterior  walls of the buildings in Park Place,  and
those areas of Park Place which house mechanical,  electrical or other equipment
or are otherwise  determined from time to time by Lessor to be used in operating
or maintaining Park Place.  "Common Area Charges"  include,  but are not limited
to,  the cost of  maintaining,  repairing,  and  replacing  and  repaving  (when
necessary) the parking and other designated  common areas;  supplies,  tools and
materials  purchased and/or used in connection with repairs,  maintenance and/or
replacements;  wages,  salaries,  and fringe  benefits of all  employees  of the
Lessor for the  portion  of time they are  directly  engaged  in the  operation,
maintenance  and  security  of Park  Place,  including  license  and  fees  (but
excluding wages, salaries and benefits of executive  employees);  removing snow,
ice,  and debris from the  roadways  and parking  areas for  Lessee's use during
normal  business hours;  removal of customary and normal trash;  maintaining and
repairing or repainting (when necessary)  directional signs,  pavement markings,
and parking lot  striping;  repairing  and replacing  (when  necessary)  outdoor
lighting  facilities;  maintaining  the  grass  and  otherwise  caring  for  the
replanting (when  necessary) all shrubbery and landscape  areas;  providing such
security as Lessor,  in its sole  discretion,  deems  advisable;  accounting and
legal fees for common areas at Park Place; utilities,  heating,  ventilation and
air-conditioning charges allocable to designated common areas and other building
service areas.

              (c)  Starting with the Commencement Date and continuing throughout
the Terms of this  Lease,  Lessee  shall pay Lessor in  advance  as  hereinafter
described and as Additional  Rent,  Lessee's  Pro-Rata  Share of all Common Area
Charges for said period.  "Lessee's  Pro-Rata  Share"  shall be a fraction,  the
numerator  of which shall be the floor area within the Leased  Premises  and the
denominator  of which shall be the total floor area within all buildings in Park
Place. The Initial Lessee's Pro-Rata Share shall be 7%.


                                      -37-
<PAGE>



              (d)  On or before the  Commencement  Date, on or before the end of
each and every Lease year,  and at such other time(s) as is deemed  desirable by
lessor in its sole  discretion,  Lessor  shall  forward to Lessee a "Common Area
Charges  Statement",  which shall contain Lessor's latest estimate of the Common
Area  Charges  for the then  current or the then  upcoming  (as the case may be)
Lease Year,  and a statement  of Lessee's  Pro-Rata  Share  thereof.  Landlord's
failure to forward,  or to timely  forward,  any Common Area  Charges  Statement
shall not excuse Lessee from its liability for Lessee's Pro-Rata Share of Common
Area Charges.

              (e)  Each  month  during the Term of this  Lease,  along with each
monthly  installment of Base Rent,  beginning with the Commencement Date, Lessee
shall pay to Lessor,  in advance,  an amount  equal to  one-twelfth  (1/12th) of
Lessee's  Pro-Rata  Share of the  Common  Area  Charges as set forth in the then
latest Statement.  If the Commencement Date is a day other than the first day of
a calendar month, then the amount of Common Area Charges due for the first month
and the last month of the Term shall be pro rated on the basis of a thirty  (30)
day month. As soon as practicable near the end of each and every Lease Year, but
no later than 90 days after the end of the Lease year,  Lessor  shall  submit to
Lessee an "Actual Common Area Charges Statement" prepared by Lessor showing that
the Common Area Charges for the then preceding  Lease Year actually  were.  With
the next monthly  installment  of Base Rent due after  Lessee's  receipt of such
Statement,  Lessee shall pay Lessor or Lessor shall credit  Lessee,  as the case
may be the difference  between Lessee's Pro-Rata Share of the actual Common Area
Charges  for said  Lease  Year as shown on said  Statement  and the total of all
Common Area Charges paid by Lessee to Lessor for said Lease Year.

         9.   NON-LIABILITY OF LESSOR
              -----------------------

              (a)  Except  as  otherwise  expressly  provided  in this  Lease or
unless caused by the negligence or intentional  misconduct of Lessor or Lessor's
employees,  agents  and  contractors  while  acting  within  the  scope of their
employment,  Lessor shall not be responsible or liable to Lessee for any loss or
damage to persons or property,  or any  interference or interruption of Lessee's
use of the Leased  Premises,  that may be occasioned by (I) water,  gas,  steam,
wind or the bursting, stoppage or leaking of any pipes, sewer or water lines, or
other  conduits,  fixtures or equipment;  (ii) the  interruption  of any utility
services  to the  Leased  Premises  caused  by the  utility  company;  (iii) any
repairs,  alterations,  maintenance or additions to the Leased  Premises or land
and  building of which they are a part;  (iv) any  casualty;  (v) theft or other
criminal  conduct;  or (vi) the acts or omissions of persons occupying any space
adjacent to the Leased Premises.

              (b)  No  provisions  of this  Lease  shall be deemed to confer any
rights  upon any  person or  entities  other  than the  parties  to this  Lease,
permitted successors and assigns and mortgages.


                                      -38-
<PAGE>



              (c)  Notwithstanding  anything  to the  contrary  provided in this
Lease, it is  specifically  understood and agreed that there shall be absolutely
no personal  liability on the part of Lessor,  including  partners in Lessor and
their  respective  successors  and assigns,  with respect to its  performance or
observance of any of the terms, covenants and conditions of this Lease, and that
Lessee shall look solely to the equity of the Lessor in the land and building of
which the Leased  Premises  form a part for the  satisfaction  of each and every
remedy  of Lessee  in the  event of any  breach  by Lessor of any of the  terms,
covenants  and  conditions  of this Lease to be performed or observed by Lessor,
such exculpation of personal  liability to be absolute and without any exception
whatsoever.

              (d)  If  Lessor  shall  fail  to  comply  fully  with  any  of its
obligations under this Lease,  Lessee may seek and enforce specific  performance
of the Lease against Lessor and pursue such other  equitable  remedies as may be
available to Lessee.  Notwithstanding  the foregoing,  the result of such action
shall be subject to the provisions of Paragraph 9(c) hereof.

         10.  INDEMNITY
              ---------

              Lessee  agrees to  indemnify  and save  Lessor  harmless  from and
against any and all claims,  demands,  costs and  expenses  (including,  but not
limited  to,  reasonable  attorneys'  fees  and  litigation  costs)  for,  or in
connection  with,  any  accident,  injury or damage  whatsoever to any person or
property (I) arising directly or indirectly out of Lessee's use of occupation of
the Leased  Premises,  (ii) occurring in, on or about the Leased  Premises or on
the sidewalks  adjoining the same, or (iii) arising  directly or indirectly from
any act or  omission of Lessee or any of Lessee's  licenses,  servants,  agents,
employees or  contractors.  The foregoing  indemnity shall not apply to any such
claim or demand proximately caused by the negligence or misconduct of Lessor, or
its  employees,  agents and  contractors  while acting within the scope of their
employment.

         11.  LIABILITY INSURANCE
              -------------------

              (a)  Lessee,  at Lessee's sole expense,  shall obtain and maintain
in  effect at all  times  starting  with the  Commencement  Date and  continuing
throughout the term of this Lease, a policy or policies of comprehensive general
public liability insurance,  insuring Lessor,  Lessor's  mortgagee(s) and Lessee
against any liability for injury, death or property damage occurring upon, in or
about any part of the Leased Premises or any  appurtenances  thereto,  affording
protection  to the limits of not less than One Million  Dollars  ($1,000,000.00)
with  respect  to bodily  injury or death of any one  person,  and not less than
Three Million Dollars  ($3,000,000.00) with respect to any one incident, and not
less than Five Hundred Thousand Dollars  ($500,000.00)  with respect to property
damage.  The foregoing  minimum  limits may, at Lessor's  option and upon thirty
(30) days' notice to Lessee, be increased from time to time to reflect inflation
or changed conditions.

              (b)  The insurance  policy(ies)  required to be procured by Lessee
under this Lease:


                                      -39-
<PAGE>


                   (i)   Shall  be  issued  by  a  reputable  insurance  company
licensed to do  business  in the State of Maryland  and shall have such form and
content as shall be approved by Lessor.

                   (ii)  Shall be  written as primary  policy  coverage  and not
contributing with, or in excess of, any coverage which Lessor may carry.

                   (iii) Shall have an endorsement thereto to the effect that no
act or  omission by Lessee  shall  affect the  obligation  of the insurer to pay
Lessor the full  amount of any loss  sustained  by Lessor  and shall  contain an
express  waiver of any right of  subrogation  by the insurance  company  against
Lessor, its agents and employees.

                   (iv)  Shall name Lessor as an additional named insured.

              (c)  On or before the Commencement Date, and at least fifteen (15)
days before the expiration date of the policy,  Lessee shall deliver to Lessor a
certificate  of insurance  evidencing  the  existence  and good  standing of the
liability  policy  referred to in Paragraph  11(a),  together  with  evidence of
payment of all premiums.  The insurance  required to be carried under this Lease
may be carried  under a blanket  policy  covering the Leased  Premises and other
locations of Lessee. The insurance policy required to be carried by Lessee shall
provide  that such  insurance  policy  shall not be canceled  unless  Lessor and
Lessor's mortgagee(s) shall have received thirty (30) days' prior written notice
of cancellation.  In the event that Lessee shall,  prior to the thirtieth (30th)
day  before  any  insurance  policy  will  lapse or  terminate,  fail to furnish
evidence of the coverage and pay the premium therefor for a period not exceeding
one year,  and the  premiums  so paid by Lessor  shall be payable by Lessee,  on
demand, as Additional Rent.

         12.  HAZARD INSURANCE
              ----------------

              (a)  Starting with the Commencement Date and continuing throughout
the Term of this  Lease,  Lessee  shall pay to Lessor,  or such  other  party as
Lessor shall designate by written notice to Lessee, as Additional Rent, Lessee's
Pro-Rata Share, as defined in Paragraph 12(e) hereof,  of the premiums and other
charges (the "Premiums") that may be incurred or contracted for or by Lessor for
fire and casualty  insurance  coverage  for the land and  buildings of which the
Leased  Premises form a part,  including  protection  from such perils as may be
insured against under a broad form extended coverage  endorsement or on all risk
of physical loss policy,  and further  including  loss of rental  coverage in an
amount equal to the Rent for one (1) Lease Year.  The premiums for all insurance
to be  obtained  by  Lessor  under  this  Paragraph  12(a)  shall be  reasonably
competitive  with the  premiums  charged for  similar  insurance  protection  by
reputable  insurers for  comparable  properties.  Lessee agrees that it will not
store  gasoline or other  explosive,  flammable or toxic  material in the Leased
Premises or do anything which may cause Lessor's  insurance  company to void the


                                      -40-
<PAGE>



policy covering the Leased Premises or to increase the premium thereon, and that
Lessee will  immediately  conform to all rules and regulations from time to time
made or established by Lessor's  insurance  company or insurance  rating bureau.
Lessor will do everything reasonably possible and consistent with the conduct of
Lessee's  business  to obtain the lowest  possible  rates for  insurance  on the
Leased Premises.  If, however,  the cost to Lessor of obtaining insurance on the
Leased  Premises  (or the  building  which the Leased  Premises  are located) is
increased  due to the  Lessee's  occupancy  thereof,  and the  Lessor's  insurer
provides evidence that said increase is the direct cause of Lessee's  occupancy,
Lessee agrees to pay,  promptly  upon demand,  as  additional  rental,  any such
increase.

              (b)  On or before the Commencement Date and before the due date of
each and  every  bill for the  Premiums,  Lessor  shall  forward  to  Lessee  an
"Insurance  Statement" which shall contain an estimated  statement of the amount
due from Lessee from time to time as Lessee's  Pro-Rata  Share of the  Premiums.
Lessor's failure to forward, or to timely forward, any Insurance Statement shall
not  excuse  Lessee  from  its  liability  for  Lessee's  Pro-Rata  Share of the
Premiums.

              (c)  Each and every  month  during the Term of this  Lease,  along
with its monthly installment of Fixed Rent,  beginning on the Commencement Date,
Lessee  shall pay  Lessor  an amount  equal to  one-twelfth  (1/12) of  Lessee's
Pro-Rata  Share  of the  Premiums  as set  forth in the  then  latest  Insurance
Statement,  which  shall  be  credited  toward  Lessee's  Pro-Rata  Share of the
Premiums when the same are due and payable.  Should Lessee's monthly installment
payments on account of Lessee's Pro-Rata Share of the Premiums for the period to
which the Premiums relate exceed the actual amount of Lessee's Pro Rata Share of
such Premiums, the excess amount shall be credited against Lessee's installments
for Premium thereafter  becoming due. If the Commencement Date is other than the
first day of a period to which the Premiums relate, then the installments of the
Premiums  due from the Lessee  shall be pro rated on the basis of a thirty  (30)
day month.

              (d)  Notwithstanding  the  provisions  of  Paragraph  12(c) above,
Lessor may, upon ten (10) days' written notice to Lessee,  require Lessee to pay
Lessee's  Pro- Rata Share of the  necessary  Increased  Premiums due to Lessee's
occupancy at such times as the  Premiums  are due and payable to the  respective
insurance  company or companies or in such manner as is required of Lessor under
any mortgage, whether such payments be in lump sum or other installments.

              (e)  Lessee's  Pro-Rata  of  the  Premiums  shall  be of  all  the
Premiums due for the land and building of which the Leased Premises form a part.
As used in this Paragraph 12, "Lessee's Pro Rata Share" shall be a fraction, the
numerator  of which shall be the floor area within the Leased  Premises  and the
denominator  of which shall be the total floor area within the building of which
the Leased Premises form a part.

              (f)  Lessor  hereby   releases   Lessee  from  any  liability  and
responsibility  to Lessor to anyone  claiming  through or under Lessor by way of
subrogation or otherwise,  for any and all loss or damage to the Leased Premises
caused by fire or any  casualty  covered by  insurance  to the extent  insurance


                                      -41-
<PAGE>


proceeds are received  therefor,  even if such fire or other casualty shall have
been caused by the fault or negligence of Lessee,  or anyone for whom Lessee may
have been responsible.  Lessor's  insurance  policies shall include  appropriate
clauses (i) waiving all rights of  subrogation  against  Lessee with  respect to
losses payable under such  policies,  and (ii) agreeing that such policies shall
not be  invalidated  should the insured waive in writing prior to a loss any and
all rights of recovery against the other party hereto for losses covered by such
policies.

         13.  DAMAGE TO THE DEMISED PREMISES
              ------------------------------

              (a)  In the event of partial or total damage or destruction of the
Leased  Premises  by fire,  other  casualty,  or any  cause  whatsoever  (except
condemnation),  Lessee shall give immediate  notice to Lessor.  If the damage or
destruction  is insured  against by Lessor,  this Lease  shall  continue in full
force and effect,  and, to the extent that insurance  proceeds  respecting  such
damage or  destruction  are  subject  to being  utilized  and,  in fact,  may be
utilized by Lessor for repair,  Lessor shall cause such damage or destruction to
be repaired with reasonable speed at the expense of Lessor,  except as otherwise
hereinafter  provided  in this  Paragraph  13. If in the  reasonable  opinion of
Lessor the damage or destruction  is such that repair thereof cannot  reasonably
be  completed  within  ninety  (90) days of the date the  damage or  destruction
occurs,  Lessor  shall have the right to  terminate  this Lease by the giving of
written  notice to such effect to Lessee  within thirty (30) days of the date of
Lessor's receipt of Lessee's notice of damage or destruction.  In no event shall
Lessor be  required  to restore or repair  Lessee's  personal  property or other
contents within the Leased Premises.  Due allowance shall be made for reasonable
delay which may arise by reason of Lessor's  adjustment of loss under  insurance
policies  and on account of labor  troubles or any other cause  beyond  Lessor's
control. To the extent that the Leased Premises are rendered  untenantable,  the
Rent  and  Additional  Rent  shall  proportionately  abate.  If  the  damage  or
destruction  is not covered by  insurance  maintained  by Lessor or if insurance
proceeds  respecting the damage or destruction are not subject to being utilized
for repair and, in fact, may be not so utilized, Lessor shall not be required to
repair the damage or  destruction.  In the event the damage or destruction is so
extensive to the  building of which the Leased  Premises are a part as to render
it uneconomical, in Lessor's opinion, to restore the Leased Premises, the Lease,
at the option of Lessor,  shall be terminated  upon written notice to Lessee and
Lessee shall immediately thereafter vacate the Leased Premises and surrender the
same to Lessor.  No such termination  shall release Lessee from any liability to
Lessor from any of the  obligations or duties imposed on Lessee under this Lease
prior  to the  damage.  Upon  any  termination  of this  Lease  pursuant  to his
Paragraph 13(a),  Rent and Additional Rent shall be prorated and adjusted to the
date of such termination.

              (b)  Lessee hereby  waives any and all right of recovery  which it
might  otherwise  have against  Lessor,  its agents and  employees,  for loss or
damage to Lessee's contents, furniture, furnishings, fixtures and other property
removable  by Lessee under the  provisions  of this Lease to the extent that the
same is to be covered by Lessee's insurance  thereunder,  except where such loss
or damage  may  result  from the  negligence  of fault of  Lessor,  its  agents,
employees or contractors.


                                      -42-
<PAGE>



         14.  EMINENT DOMAIN
              --------------

              (a)  If during the term of this  Lease,  the Leased  Premises,  or
such a substantial  portion of the Leased  Premises as shall prevent Lessee from
conducting its normal business, shall be taken by proper authority for public or
quasi-public  use, then Lessee may terminate this Lease by giving Lessor written
notice of  termination  within  thirty (30) days after  receipt of notice of the
taking,  and Lessee's  obligation  to pay rent,  taxes,  and other charges shall
terminate as of the date of the termination notice. If only a part of the Leased
Premises is taken and the part not taken shall be reasonably  sufficient for the
purpose of conducting Lessee's normal business,  this Lease shall remain in full
force  and  effect,   except  that  the  Rent  and  Additional   Rent  shall  be
proportionately reduced.

              (b)  All  compensation  awarded for any taking shall belong to and
be the property of Lessor. Nothing contained herein, however, shall be construed
to preclude Lessee from  prosecuting  any claim directly  against the condemning
authority  for loss of  business or  depreciation,  damage or cost of removal of
personal property  belonging to Lessee so long as the claim does not diminish or
otherwise  adversely  affect  Lessor's award or the award  otherwise  payable to
Lessor's mortgagee.

         15.  CONDITION OF LEASED PREMISES; MAINTENANCE AND REPAIR
              ----------------------------------------------------

              (a)  Except for the repairs that Lessor is specifically  obligated
to make  under  Paragraph  15(b)  hereof,  and  except  for  repairs  covered by
contractor  warranties held by Lessor for Lessor's  benefit,  during the term of
this Lease,  Lessee, at Lessee's sole cost and expense,  shall promptly make all
repairs,  perform all maintenance,  perform all custodial  services and make all
replacements  in and to the Lease  Premises  that are necessary in order to keep
the  Leased  Premises  in good  order and  repair  and in a safe and  tenantable
condition. Without limiting the generality of the foregoing, Lessee, at its sole
cost and expense,  is specifically  required to make promptly all repairs to (i)
any pipes,  water and waste lines,  ducts,  wires or conduits  beneath or in the
Leased  Premises  or within the ceiling of the Leased  Premises;  (ii) any glass
windows included within the Leased Premises;  (iii) Leasee's  sign(s);  (iv) any
electrical,  natural gas (if any),  heating,  ventilating and air  conditioning,
plumbing,  and other  systems,  equipment,  fixtures  and items  installed in or
servicing the Leased Premises; (v) the floors,  ceilings and walls of the Leased
Premises;  (vi) the entrance and exit and auxiliary driveways, if any, which are
part of and  service  the Leased  Premises;  and (vii) any portion of the Leased
Premises  damaged by Lessee's use or occupancy of the Leased  Premises or by any
act,  omission or  negligence  of Lessee,  or any of its  respective  employees,
agents, invitees,  licensees or contractors.  All repairs, and replacements made
by Lessee shall  utilize  materials  and  equipment  which are at least equal in
quality and usefulness to those originally used in the Leased Premises.  Lessee,
at Lessee's expense,  shall enter into one (1) or more service contracts for the

 
                                      -43-
<PAGE>



maintenance  of the  heating,  ventilating  and  air  conditioning  systems  and
equipment.  Lessee shall keep the Leased Premises free of all insects,  rodents,
vermin and pests of every type and kind. Lessee shall also,  promptly and at its
own expense,  keep any sidewalks and curbs adjacent to the Leased Premises clean
and free from snow,  ice,  dirt and rubbish.  Lessee  shall not  (directly or by
sufferance)  place any equipment,  materials or debris on the roof of the Leased
Premises, or cut, drive nails into or otherwise mutilate such roof.

              (b)  Lessor shall within  thirty (30) days (or such longer  period
of time as may  reasonably  be required  by Lessor)  after  written  notice from
Lessee with respect thereto,  make necessary  structural repairs to the exterior
walls  and  shall  keep  in  good  order,  condition  and  repair  the  exterior
foundations, downspouts, gutters and roof of the Leased Premises and the portion
of the  plumbing  and sewage  system  located  outside the building in which the
Leased  Premises  are located (it being  understood  and agreed that  Landlord's
obligations exclude the exterior and interior of all windows, doors, plate glass
and signs, and repairs  required by any casualty except as otherwise  covered by
Paragraph 13 herein). Lessee shall, upon demand, reimburse Lessor for reasonable
costs of making  any such  repairs or  replacements  caused by  Lessee's  use or
occupancy  of the Leased  Premises  or by any act,  omission  or  negligence  of
Lessee,   any  subtenant  or  concessionaire  of  Lessee,  or  their  respective
employees,  agents,  invitees,  licensees or contractors  (excluding  repairs or
replacements caused by Lessee's normal use).

              (c)  Lessee  hereby  covenants  to contain all  garbage,  rubbish,
waste,  trash and debris  generated  in  conjunction  with its use of the Leased
Premises in  containers  provided by Lessor (which shall be emptied no more than
three times per week, but at least once a week) so as not to constitute a safety
or fire hazard.

         16.  ALTERATIONS
              -----------

         Lessee  shall  not  make  any  non-structural   interior   alterations,
additions or improvements in or to the Leased Premises without the prior written
consent of Lessor in each  instance,  which  consent  shall not be  unreasonably
withheld  or  delayed.   Lessee  shall  not  take  any  structural  or  exterior
alterations,  additions or improvements to the Leased Premises without the prior
written  consent of Lessor.  Should Lessor fail to respond  within  fifteen (15)
working  days after  Lessor's  receipt of any  written  request  from Lessee for
Lessor's  consent  to  any  proposed  alterations,  additions  or  improvements,
Lessor's   consent  shall  be  deemed  to  have  been  granted.   All  permitted
alterations, additions and improvements made by Lessee shall be performed (i) in
a good and workmanlike  manner, (ii) in accordance with all applicable legal and
insurance  requirements,  (iii) only after receipt by Lessee and presentation to
Lessor of all necessary permits and licenses, and (iv) at Lessee's sole expense.
Except for Lessee's removable trade fixtures, and all improvement made by Tenant
in the processing and storage areas, all improvements,  repairs, alterations and
additions and all other non-trade  fixtures,  whether  installed before or after
the  execution  of this  Lease,  shall  remain  upon the Leased  Premises at the
expiration or sooner termination of this Lease and become the property of Lessor
without  payment  therefor by Lessor,  unless prior to the  termination  of this



                                      -44-
<PAGE>



Lease,  Lessor shall have given written  notice to Lessee to remove the same, in
which event Lessee, at its expense, will remove such alterations,  improvements,
additions  and/or  fixtures  and  repair and  restore  any and all damage to the
Leased Premises caused by the installation and/or removal thereof.

         17.  SIGNS
              -----

              Lessee may not install any sign  without  Lessor's  prior  written
consent.  All signs shall be in strict  compliance  with the sign  criteria  set
forth in Exhibit "C" attached hereto and made part hereof.  Lessee shall install
all exterior signs for the Leased Premises at the cost and expense of Lessee. No
sign, advertisement or notice shall be inscribed,  painted, affixed or otherwise
displayed on any part of the outside or the inside of the Leased Premises or the
building  of which the Leased  Premises  are a part,  unless  Lessor  shall have
approved the sign, advertisement,  or notice in writing prior to installation of
the same. If any sign,  advertisement,  or notice is exhibited by Lessee without
having first obtained Lessor's approval thereof,  Lessor shall have the right to
remove the same and Lessee shall be liable for any and all expenses  incurred by
Lessor in said  removal.  No signs made of paper and visible from outside of the
Leased Premises shall be allowed in the Leased Premises. No mobile sign, such as
may be affixed to the side of a truck or a trailer or a mobile platform shall be
permitted in the parking area.

         18.  LAWS AND INSURANCE STANDARDS
              ----------------------------

         Lessee  shall,  at  Lessee's  sole  expense,  promptly  comply in every
respect with all  applicable  laws,  ordinances,  rules and  regulations  of all
federal,  state,  county, and municipal  governments now in force or that may be
enacted in the future,  all applicable  and  enforceable  directions,  rules and
regulations of the fire marshall,  health officer,  building  inspector or other
proper  officers  of  any  governmental  agency  having  jurisdiction,  and  the
applicable standards established from time to time by the National Board of Fire
Underwriters,  the National Fire Protective Association,  or any similar bodies.
Lessee expressly covenants and agrees to indemnify and save Lessor harmless from
any  penalties,  damages or charges  imposed for any violation of the foregoing.
Notwithstanding the foregoing,  Lessee shall not be required to make any changes
or modifications to the Leased Premises, unless (a) the same are required due to
Lessee's specific use and/or occupancy of the Leased Premises,  (b) the same are
required due to structural specifications (beyond building standard) required by
Lessee, or (c) the same relate to repairs, maintenance or other responsibilities
of Lessee under this Lease, e.g., Paragraph 15(a) hereof.

         19.  MECHANIC'S LIENS
              ----------------

              Lessee shall do all things  necessary to prevent the filing of any
mechanics' or other liens against the Leased Premises,  or the land the building
of which the Leased  Premises are part,  by reason of work,  labor,  services or
materials  supplied or claimed to have been supplied to Lessee or anyone holding
the Leased premises,  through or under Lessee.  If any lien shall at any time be
filed,  Lessee shall either cause the lien to be discharged of record within ten


                                      -45-
<PAGE>



(10) days after knowledge of its filing or, if Lessee in its discretion and good
faith determines that the lien should be contested,  shall furnish such security
as may be necessary to prevent the filing of any foreclosure  proceedings during
the pendency of the contest.  If Lessee shall fail to discharge  any lien within
such period or fail to furnish  such  security,  then,  in addition to any other
right or remedy,  Lessor may, but shall not be obligated to,  discharge the same
either by paying the amount  claimed to be due or by procuring  the discharge of
lien by deposit in court or by giving  security or in such other manner as is or
may be  prescribed  by law.  Lessee  shall  repay to Lessor  on demand  all sums
disbursed or deposited by Lessor pursuant to the foregoing provisions, including
the  expenses  and  reasonable  attorneys'  fees  incurred  by  Lessor.  Nothing
contained  in this Lease shall imply that  Lessee has any  authority  or consent
from Lessor to subject Lessor's estate to any mechanics', materialman's or other
lien.

         20.  ASSIGNMENT AND SUBLETTING
              -------------------------

              (a)  Lessee shall not assign, mortgage or encumber any interest in
this Lease or sublet all or any part of the Leased  Premises  without  the prior
written consent of Lessor.  Lessor shall not unreasonably  withhold or delay its
consent to an assignment or subletting of this Lease.

              (b)  No  permitted   assignment  or  subletting   shall   release,
discharge or affect the liabilities of Lessee as provided for in this Lease, and
Lessee  shall  at all  times  remain  primarily  liable  under  this  Lease.  An
assignment  by operation of law shall be deemed a  prohibited  assignment  under
this Paragraph.

         21.  INSOLVENCY
              ----------

              Lessor may,  at its option,  declare  this Lessee  terminated  and
reenter  and  resume  possession  of the  Leased  Premises,  if Lessee  shall be
adjudicated  a  bankrupt  or  insolvent,  or if a receiver  or trustee  shall be
appointed for Lessee's business or property,  or if Lessee shall file a petition
in bankruptcy or insolvency, or if a petition or other proceeding shall be filed
by or against Lessee seeking corporate or other  reorganization,  liquidation or
other similar relief or if Lessee shall make an assignment or an arrangement for
the benefit of creditors,  or if an involuntary  petition shall be filed against
Lessee in  bankruptcy or  insolvency  and such  petition  shall not be dismissed
within sixty (60) days.


                                      -46-

<PAGE>



         22.  REMEDIES CUMULATIVE
              -------------------

              The various rights,  elections and remedies of Lessor contained in
this  Lease  shall  be  cumulative,  and no one of them  shall be  construed  as
exclusive of any of the others,  or of any right,  priority or remedy allowed or
provided for by law.

         23.  WAIVER OR DEFAULT
              -----------------

              The waiver by either  party of any default in the  performance  by
the other of any covenant shall not be construed to be a waiver of any preceding
or subsequent  default of the same or any other covenant  contained herein.  The
subsequent  acceptance  of Rent or other  sums by  Lessor  shall not be deemed a
waiver of any  preceding  default  other  than the  failure of Lessee to pay the
particular rental or other sum so accepted.

         24.  HOLDING OVER
              ------------

              If Lessee shall hold  possession of the Leased  Premises after the
end of the term or other termination of this Lease, Leases shall be deemed to be
occupying the Leased Premises as a tenant from month to month, subject to all of
the  conditions,  provisions and obligations of this Lease;  provided,  however,
Lessee  shall be liable for any and all  damages  and  expense  that  Lessor may
sustain by virtue of Lessee's holding over,  including,  but not limited to, any
amount for which Lessor may be liable under,  or as a result of, any other lease
entered into by Lessor for a term  beginning at or after the  expiration  of the
term of this Lease.  Nothing  contained  in this Lease shall be  construed  as a
consent by Lessor to the  occupancy  or  possession  of the Leased  Premises  by
Lessee after the expiration of the term of this Lease. Rather, at the end of the
term of the  Lease,  Lessor  shall be  entitled  to the  benefit  of all laws or
ordinances  relating to the recovery of the  possession  of lands and  tenements
held over by tenants that now may be in force or hereafter  may be enacted,  and
Lessor may proceed under such laws or ordinances,  without notice to Lessee, all
statutory notice requirements being expressly waived by Lessee.


                                      -47-
<PAGE>



         25.  SURRENDER
              ---------

              Upon the expiration of the term of this Lease,  Lessee immediately
shall surrender the Leased Premises broom-clean and in good order and condition,
ordinary wear and tear excepted.  All of Lessee's  personal property at or about
the Leased Premises (but not permanently  affixed parts of the Leased  Premises)
shall be removed by Lessee at or before the expiration of this Lease or shall be
deemed  abandoned by Lessee.  Any damage to the Leased  Premises  caused by such
removal shall be repaired by Lessee at its own expense.

         26.  DEFAULT
              -------

              (a)  If Lessee fails to pay any Rent or  Additional  Rent when due
and such failure continues for a period of five (5) days after Lessor shall have
made written demand on Lessee for payment, or if Lessee otherwise is at any time
in default under this Lease and continues in such default for a period of thirty
(30) days after  Lessor  shall  have  demanded  in  writing to Lessee  that such
default be cured, or if such latter default is not capable of being cured within
a fifteen (15) day period,  such additional time (not to exceed  forty-five (45)
days) as is reasonably necessary to cure such default,  provided Lessee promptly
commences  and  diligently  pursues to cure such  default,  then  Lessor may, at
Lessor's  option,  terminate this Lease (without  releasing Lessee of liability)
and by summary  proceedings or other manner  prescribed by law, reenter and take
possession of the Leased  Premises.  If Lessor  should so terminate  this Lease,
Lessee  shall pay to Lessor as damages,  upon demand,  all expenses  (including,
without limitation,  attorneys' fees) of any proceedings  necessary in order for
Lessor  to  recover  possession  of the  Leased  Premises  and the  expenses  of
reletting  the  Leased  Premises  (including,  without  limitation,   reasonable
attorneys'  fees,  brokerage  commissions,  and the costs of putting  the Leaded
Premises in good order and preparing it for reletting, plus either:

                   (i)  Liquidated damages in an amount equal to the excess,  if
any,  of the Rent and  Additional  Rent that  would have been  payable  over the
unexpired  portion of the term of this Lease over the rental value of the Leased
Premises for such unexpired  portion of the term of this Lease, as discounted at
the  then  publicly  declared  prime  rate of the  Federal  Bank  in  Baltimore,
Maryland; or

                   (ii)  Damages  in an amount  to the  excess,  if any,  of the
monthly  Rent and  Additional  Rent over the  monthly  rentals,  if any, if fact
collected by Lessor as the result of a reletting of the Leased  Premises at such
rent and upon such terms as Lessor,  in its sole  discretion,  elects to accept.
Separate  actions may be maintained  each month by Lessor to recover the damages
then due as provided for in this subparagraph (ii) and any such action shall not
prejudice the rights of Lessor to collect damages for any subsequent  month in a
similar proceeding.

              (b)  No re-entry or reletting of the Leased  Premises,  whether or
not the term of such reletting  extends beyond the term of this Lease,  shall be
construed  as an  election  by Lessor to: (i) accept a  surrender  of the Leased
Premises, or (ii) release Lessee of any of its obligations under this Lease.


                                      -48-
<PAGE>



              (c)  Should Lessor,  pursuant to its rights under  Paragraph 26(a)
hereof,  elect to terminate  this Lease and reenter and take  possession  of the
Leased Premises,  Lessor shall use commercially  reasonable efforts,  under then
prevailing circumstances, to relet the Leased Premises.

         27.  ACCESS TO LEASED PREMISES
              -------------------------

              (a)  Lessor and its  designees  shall have the right  (subject  to
being accompanied by Lessee's  representative at all times for security reasons)
to enter  upon the  Leased  Premises  at all  reasonable  hours,  after 24 hours
notice,  (and in  emergencies,  at all times):  (i) to inspect the same; (ii) to
make repairs,  additions,  or alterations to the Leased Premises or the building
in which the same are located or any property  owned or  controlled by Landlord;
(iii) to  exhibit  the  Leased  Premises  to any  prospective  buyer,  lessee or
mortgagee or their respective agents or representatives; and (iv) for any lawful
purpose.

              (b)  For a period  commencing three (3) months prior to the end of
the term,  Lessor may have reasonable  access to the Premises for the purpose of
exhibiting  the same to  prospective  tenants and to post any "For Rent" or "For
Lease" signs upon the Leased Premises.

         28.  SUBORDINATION AND ATTORNMENT
              ----------------------------

              (a)  This  Lease is  subject  and  subordinate  to the lien of all
present  and  future  mortgages  and/or  deeds of trust  encumbering  the Leased
Premises,  all present and future advances under such mortgages  and/or deeds of
trust, and all renewals, extensions,  modifications,  recastings or refinancings
of such  mortgages  and/or deeds of trust.  Lessee agrees that, in the event any
proceedings are brought under or for the foreclosure of any such mortgage and/or
deed of trust,  Lessee shall, if requested to do so by the beneficiary  under or
holder of such mortgage  and/or deed of trust or by any successor in interest to
such beneficiary or holder, automatically become the lessee of such beneficiary,
holder  or  successor  in  interest  and  shall  automatically  attorn  to  such
beneficiary, holder and/or successor in interest and recognize such beneficiary,
holder  and/or  successor  in  interest  as the  Lessor  under  this  Lease.  In
confirmation of such attornment, however, Lessee shall, at the request of Lessor
or any  beneficiary,  holder or  successor  in  interest,  promptly  execute any
requisite or  appropriate  certificate or other document for the benefit of such
beneficiary, holder and/or successor in interest.

              (b)  In the event that,  after the date of this Lease, a bona fide
loan shall be made by an insurance company, savings bank, commercial bank, trust
company, or other lender and secured by a mortgage or deed of trust constituting


                                      -49-
<PAGE>



a lien  against  any  portion  of the  Leased  Premises  and said  lender  shall
complete,   execute   and   acknowledge   a   subordination,   attornment,   and
non-disturbance agreement, then and in that event, Lessee shall subordinate this
Lease to said mortgage or deed of trust by executing and  acknowledging the said
subordination, attornment and non-disturbance agreement.

              (c)  Upon any assignment or  termination  of Lessor's  interest in
the Leased Premises,  Lessee shall,  upon request,  attorn in writing to the new
owner of the Leased  Premises and shall pay to the new owner all rents and other
monies  required to be paid and perform all of the other  obligations  of Lessee
under this  Lease.  Following  any sale by Lessor of the  property  of which the
Leased  Premises are a part, all  obligations to the assigning  Lessor to Lessee
shall cease and  terminate and Lessee shall look solely to the successor for the
performance of Lessor's duties hereunder.

              (d)  Notwithstanding  the  foregoing,  this  Lease  shall  not  be
terminated so long as Lessee is not in default of any provisions in this Lease.

              (e)  Lessor shall,  within fifteen (15) days after the date hereof

(or prior to the effective date of any encumbrance  mentioned in this Section 28
created after the date hereof)  obtain from the holder of any such  encumbrance,
an agreement whereby if such holder or any successor in interest shall come into
possession  of the  Leased  Premises,  or any part  thereof,  by  dispossession,
foreclosure or otherwise,  or shall become the owner of such  property,  or take
over the rights of Lessor to such  property,  said holder  shall not disturb the
possession, use or enjoyment of the Leased Premises by Lessee, its successors or
assigns,  nor  disaffirm  this  Lease  or  Lessee's  rights  or  estate  granted
hereunder,  so long as Lessee performs all of its obligations in accordance with
the terms of this Lease.

         29.  RIGHT TO CURE DEFAULTS
              ----------------------

              (a)  If  Lessee  shall  fail  to  comply  fully  with  any  of its
obligations  under this Lease,  then, in addition to Lessor's other rights,  but
not the  duty,  to cure  such  breach  at  Lessee's  expense.  Lessee  agrees to
reimburse  Lessor,  within fifteen (15) days after Lessor submits a statement of
the amount due, as  Additional  Rent,  for all expenses  incurred by Lessor as a
result of any efforts made by Lessor to cure any such breach.

              (b)  If  Lessor  shall  fail  to  comply  fully  with  any  of its
obligations  under this Lease,  then,  in addition to Lessee's  other rights and
remedies under this Lease at law and in equity, Lessee shall have the right, but
not the duty,  to cure such breach at Lessor's  expense;  provided that prior to
the  exercise of such right to cure,  Lessee  shall give Lessor  written  notice


                                      -50-
<PAGE>



specifying  the nature of the breach and Lessor  shall be  entitled  to ten (10)
days  after  receipt of such  notice  within  which to cure said  breach or such
additional  time as may be necessary if such breach is not  susceptible  to cure
within said ten (10) days,  in which case Lessor  shall  commence to cure within
said ten (10) day period. Lessor agrees to reimburse Lessee, within fifteen (15)
days after  Lessee  submits a  statement  of the amount  due,  for all  expenses
incurred by Lessee as a result of any efforts by Lessee to cure any such breach.
If Lessor fails to reimburse  Lessee as aforesaid,  Lessee may offset the amount
due against the  payments of Rent  becoming  due  hereunder  unless  Lessor give
written  notice of dispute  within said  fifteen  (15) day period  either to the
existence of any default or the  reasonableness  of the amount expended to cure.
In the event such notice of dispute is given, the provisions of subparagraph (c)
shall govern. The right to setoff against Rent shall be subordinate to and there
shall be no setoff  against the holder of any  mortgages or deed of trust or any
purchaser  at  foreclosure  or deed in lieu thereof on all or any portion of the
Leased  Premises.  The amount of all setoffs shall be limited to the  cumulative
sum of One Hundred Thousand Dollars ($100,000.00).

              (c)  If  Lessor  has  given  notice  of  dispute  as  provided  in
subparagraph (b), Lessee may have the issues of whether the Lessor is in default
of  its  obligations  or  the  reasonableness  of  the  amount  of  expenditures
determined by arbitration.  Pending the results of such arbitration, there shall
be no setoff. In the event the arbitrators determine that Lessor was in default,
Lessor  shall pay all costs of  arbitration  and Lessee  shall have the right to
offset  all of its costs and  expenses  of  remedying  such  default  (including
unreimbursed costs of the arbitration  proceeding)  against the payments of Rent
becoming due hereunder, subject to the limitations set forth in subparagraph (b)
above. If the arbitrators  determine that Lessor was not in default, then Lessee
will pay all of the arbitration.

              (d)  If Lessor is determined  to be in default in its  obligations

under  Paragraph  15(c) of this Lease and Lessee  shall  remedy such  default in
accordance with the preceding paragraph,  Lessee shall be entitled to offset one
hundred  fifteen  percent  (115%) of the costs and  expenses of  remedying  such
default, with the additional fifteen percent (15%) being to reimburse Lessee for
its overhead.

         30.  BROKERAGE
              ---------

              Lessor hereby  acknowledges  that Montgomery Realty ("Broker") has
served as Lessor's  agent in  connection  with this Lease and agrees to pay said
Broker a  commission  as per a separate  agreement  between  Lessor and  Broker.


                                      -51-
<PAGE>



Lessor  warrants  to Lessee and Lessee  warrants to Lessor that it has not dealt
with any other  broker or real estate  agent or finder in  connection  with this
Lease and that, except for the aforesaid  commission payable to Broker, no right
or claim for  commission or other  compensation  has been created by its actions
with  respect to this Lease.  Lessor and Lessee  shall  indemnify  and hold each
other  harmless  against all loss,  liability or expense,  including  reasonable
attorney's fees and litigation costs, incurred by the other to the extent one or
the other is shown to be in breach of the foregoing warranties.

         31.  EFFECT OF CONVEYANCE
              --------------------

              If during the term of this Lease  Lessor sells its interest in the
Leased  Premises or this Lease,  then from and after the effective  date of such
sale,  Lessor  shall  be  released  and  discharged  from  any and  all  further
obligations and responsibilities  under this Lease except those already accrued.
Any such sale  shall be  subject to this  Lease and  Lessor  shall  require  any
purchaser to acknowledge the existence of Lessee's tenancy.

         32.  INTERPRETATION
              --------------

              The captions by which the  paragraphs of this Lease are identified
are for  convenience  only and shall have no effect upon the  interpretation  of
this Lease. Whenever the context so requires,  the singular number shall include
the plural,  and plural shall refer to the singular and the neuter  gender shall
include the masculine and feminine genders. If any provision of this Lease shall
be held to be unenforceable by a court, the remaining provisions shall remain in
effect and shall in no way be impaired.

         33.  ENTIRE INSTRUMENT
              -----------------

              All of the agreements previously and contemporaneously made by the
parties are  contained  in this Lease,  and this Lease cannot be modified in any
respect except by a writing executed by Lessor and Lessee.

         34.  ESTOPPEL CERTIFICATES
              ---------------------

              Recognizing  that both  parties may find it necessary to establish
to third parties, such as accountants,  banks,  mortgagees or the like, the then
current status of performance hereunder, either party, on the written request of
one to the  other  made  from  time to time,  will  promptly  furnish  a written
certificate  on the status of any matter  pertaining  to this Lease in such form
and substances as may from time to time be reasonably required.


                                      -52-
<PAGE>



         35.  NOTICES
              -------

              Any notices and other  communications  required or permitted to be
given by either  party to the other  shall be in writing  and shall be deemed to
have been served when hand  delivered  or, if the United States Mail is used, on
the second business day after the notice is deposited in the United States Mail,
postage prepaid, registered or certified mail, or by overnight delivery service,
and addressed to the parties as follows:

         To Lessee:               Jacques R. Rubin
                                  9000 Virginia Manor Road, Suite 290
                                  Beltsville, Maryland  20705

         To Lessor:               Muirkirk Manor Associates Limited Partnership
                                  9000 Virginia Manor Road, Suite 201
                                  Beltsville, Maryland   20705


Either party,  by written  notice to the other,  may change its address to which
notices are to be sent.

         36.  WAIVER
              ------

              Any waiver of either  Lessor or Lessee of any  default,  breach or
failure by the other to comply with any term,  condition,  or  provision of this
Lease shall not constitute a waiver of any other  default,  breach or failure by
such  defaulting  party.  No covenant,  term or condition of this Lease shall be
deemed to have been waived by either  party unless such waiver be in writing and
signed by the party to be charged therewith.

         37.  QUIET ENJOYMENT
              ---------------

              So  long as  Lessee  is not in  default  beyond  applicable  grace
periods,  Lessee shall have peaceful and quiet use and  possession of the Leased
Premises  without  hindrance  on the part of Lessor or any person  claiming  by,
through or under Lessor.

         38.  RECORDING THIS LEASE
              --------------------

              Lessee may not record  either this Lease nor a memorandum  thereof
among or in any public records without Lessor's prior written consent.


                                      -53-
<PAGE>



         39.  GOVERNING LAW
              -------------

              All questions with respect to  construction  of this Lease and the
rights and liabilities of the parties shall be determined in accordance with the
laws of the State of Maryland.

         40.  BENEFIT
              -------

              Subject to the restrictions on assignment and subletting set forth
in Paragraph 20, the  covenants,  terms and conditions of this Lease shall inure
to the  benefit of and be binding  upon  Lessor and Lessee and their  respective
successors and assigns.

         41.  REASONABLE CONSENT
              ------------------

              Wherever in this Lease  Lessor or Lessee is required to obtain the
consent or  approval of the other,  it is agreed  that such  consent or approval
shall not be unreasonably withheld or delayed.

         42.  TIME OF ESSENCE
              ---------------

              Time is of the  essence  in the  performance  of all of Lessor and
Lessee's obligations under this Lease.

              (See Lease Addendum for Paragraphs 43 and 44)



                                      -54-
<PAGE>



         IN WITNESS WHEREOF, the parties have executed this Lease on the day and
year first above written.



WITNESS:                              LESSOR:

                                      MUIRKIRK MANOR ASSOCIATES
                                      LIMITED PARTNERSHIP,
                                      a Maryland limited partnership

                                      By: THE ANASTASI STEPHENS GROUP, INC.


/s/ Cindi R. Caplan                   /s/ Joseph Anastasi
-------------------                   -------------------


WITNESS:                              LESSEE:


                                      BIO SCIENCE CONTRACT PRODUCTION CORP.
                                      a Maryland corporation

/s/ Cindi R. Caplan                   /s/ Jacques R. Rubin, President
-------------------                   -------------------------------


                                      -55-
<PAGE>



                              EXHIBIT "B" (PART II)

                                 LEASE ADDENDUM
                                 --------------

                                  (PARK PLACE)


         THIS  LEASE  ADDENDUM  made  as of the 12 day  of  November,  1991,  is
attached  to and made  part of that  certain  Lease of even date  herewith  (the
"Lease")  by and  between  MUIRKIRK  MANOR  ASSOCIATES  LIMITED  PARTNERSHIP,  a
Maryland limited  partnership  ("Lessor"),  and Bio Science Contract  Production
Corp., a Maryland corporation ("Lessee").

                              W I T N E S S E T H:
                              - - - - - - - - - - 

         WHEREAS,  Lessor and Lessee  have  agreed to amend,  supplement  and/or
modify  the  Lease as herein  provided,  Landlord  and  Tenant  hereby  agree as
follows:

         2.   TERM - OPTION
              -------------

         Lessee, at its option,  shall have the right to extend the Term of this
Lease on the same terms and conditions,  as the original term thereof, except as
otherwise  provided in this Addendum with respect to the amount of Base Rent due
during the respective extension period, for Two (2) additional  consecutive term
of Five (5) years (the "Extension  Period"),  subject to the satisfaction of the
following conditions:

         (i) Lessee's option to extend the Lease for the Extension  Period shall
be exercisable  only by written notice to Lessor at least ninety (90) days prior
to the commencement date of the Extension Period. If Lessee does not give Lessor
written  notice as  aforesaid,  Lessee shall be deemed to have not exercised its
respective extension option.

         (ii) At the time of exercise of the option and at the  commencement  of
the Extension Period,  Lessee shall not be in default under the Lease beyond any
applicable grace period.

         (iii) Upon  exercising  the  option,  the Base Rent will be the product
obtained by multiplying the Base Rent for the  immediately  preceding Lease Year
by one hundred four percent (104%).


                                      -56-
<PAGE>


              LESSEE IMPROVEMENTS
              -------------------

              (a)  Lessor has agreed to construct and complete the  installation
of lessee  improvements,  as set forth in  Exhibit  "B" to the  Lease,  within a
budget of one hundred and twenty  thousand and 00/100  ($120,000.00)  toward the
improvements requested by the lessee and it is agreed that the demising wall and
 .60 per S.F.  for design is part of the above  allowance.  It is agreed that all
plans,  specifications,  the General Contractor and its sub contractors, as well
as their  work  schedule,  will be  approved  by the  lessor  or its  Architect.
Payments to the General  Contractor will be made in accordance with the schedule
and method established by the lessor and its lender.

              (b)  In the event that the cost of constructing and installing the
lessee improvements to the Leased Premises exceeds the $120,000.00, lessee shall
pay directly to the General  Contractor the difference  between the cost and the
allowance.

              (c)  It is  further agreed  that  the  Lessee  accepts  Suite  280
(formerly  occupied by Homes Oil) in as is condition and the above  allowance in
(a) will be used for improvements, if any, in that suite.

         IN WITNESS  WHEREOF,  the parties have executed this Lease  Addendum on
the day and year first above written.



ATTEST:                             LESSOR:

                                    MUIRKIRK MANOR ASSOCIATES LIMITED
                                    PARTNERSHIP,
                                     A Maryland limited partnership

                                    By:  THE ANASTASI STEPHENS GROUP, INC.,
                                         its general partner



/s/ Cindi R. Caplan                 By:  /s/ Joseph Anastasi
-------------------                      -------------------



                                    LESSEE:

                                    BIO SCIENCE CONTRACT PRODUCTION CORP.
                                    a MARYLAND corporation


/s/ Cindi R. Caplan                 By:  /s/ Jacques R. Rubin, President
-------------------                      -------------------------------


                                      -57-
<PAGE>


                                   EXHIBIT "C"

                                   THIRD LEASE
                                   -----------


                                      LEASE
                                      -----

                                  (PARK PLACE)


         THIS  LEASE,  made as of this 20th day of March,  1992,  by and between
MUIRKIRK MANOR ASSOCIATES LIMITED  PARTNERSHIP,  a Maryland Limited  partnership
("Lessor"),  and BIO SCIENCE CONTRACT  PRODUCTION CORP., a Maryland  corporation
("Lessee").

                              W I T N E S S E T H:
                              - - - - - - - - - -

         That in  consideration  of the rent and mutual covenants and agreements
contained  herein,  and intending to be legally bound hereby,  Lessor and Lessee
agree as follows:

         1.   DEMISED PREMISES
              ----------------

              The  Lessor  leases  to the  Lessee  all  of  that  certain  space
described as Suite No. 260, 9000 Virginia Manor Road,  containing  approximately
8,100  square  feet of gross  leasable  area,  as is outlined in red on the plat
attached  to and  made a  part  of  this  Lease  as  Exhibit  "A"  (the  "Leased
Premises"),  and located in Park Place, Prince George's County, Maryland. Lessor
shall  construct and complete the Leased  Premises in compliance  with the plans
and  specifications  set forth in  Exhibit  "B"  attached  hereto  and made part
hereof.  "Delivery  of  Possession"  of the Leased  Premises by Lessor to Lessee
shall be deemed to have been made when Lessor's  architect  certifies in writing
that construction of the Leased Premises shall have been completed.

         2.   TERM
              ----

              The term (the  "Term") of this Lease  shall be for a term of Eight
(8) years,  eleven (11) months,  commencing on the 1sT day of April,  1992, (the
"Commencement Date") and shall expire on the last day of February,  2001. If the
Term of the Lease does not begin on the date specified  herein for reasons other
than the  fault of  Lessee,  then the  expiration  date  shall be moved  for the
commensurate amount of the delay and the rent shall be prorated accordingly.  If
the term  commences  or ends in  mid-month,  the  rent  payable  for that  month
(including,  without limitation,  Additional Rent) shall be prorated and paid on
the date of commencement or termination.


                                      -58-
<PAGE>



         3.   RENT
              ----

              (a)  The rent (the "Base Rent") shall be:

                      Year                Square Foot Rate
                      ----                ----------------

                        1                     $  9.50
                        2                     $  9.53
                        3                     $ 10.18
                        4                     $ 10.53
                        5                     $ 10.90
                        6                     $ 11.28
                        7                     $ 11.68
                        8                     $ 12.09
                        9                     $ 12.51


The term "Lease Year" shall mean each twelve (12) month  period  during the term
of this  Lease  commencing  on the  Commencement  Date.  The Base Rent  shall be
payable,  in  advance,  in  equal  monthly   installments,   the  first  monthly
installment to be due and payable on the  Commencement  Date and each subsequent
monthly  installment  to be due and  payable  on the first day of each and every
month thereafter during the term of this Lease.

              (b)  All moneys  payable by Lessee  under the terms of this Lease,
other than Base Rent, as adjusted from time to time, shall be deemed "Additional
Rent."

              (c)  Lessee  shall make all  payments of Base Rent and  Additional
Rent on a  timely  basis,  without  demand  and  without  deduction,  setoff  or
counterclaim,  except as  expressly  permitted in Paragraph  29(b)  hereof.  All
payments  of Rent and  Additional  Rent  shall be made by good and valid  check,
payable to The Anastasi  Stephens Group,  Inc., agent, 9000 Virginia Manor Road,
Suite 201,  Beltsville,  Maryland 20705, or to such other party or to such other
address as Lessor may designate  from time to time by written  notice to Lessee.
If Lessor shall at any time or times accept Base Rent or  Additional  Rent after
it shall become due and  payable,  such  acceptance  shall not excuse delay upon
subsequent occasions,  or constitute,  or be construed as, a waive of any or all
of Lessor's rights hereunder.  If any payment of Base Rent or Additional Rent is
not made within ten (10) days of when due, a late charge of five percent (5%) of
the amount of such payment shall be imposed, Lessor shall be entitled to require
the payment of Base Rent and Additional Rent by certified check if the check for
any payment by Lessee shall be dishonored by its Bank.

              (d)  Except  for the  obligations  of Lessor  expressly  set forth
herein,  this  Lease is a "net  lease" and Lessor  shall  receive  the Base Rent
hereinabove  provided as net income from the Leased Premises,  not diminished by
any  imposition  of any expenses or charges  required to be paid to maintain and
carry the Leased  Premises or to continue the  ownership  of Lessor,  other than
payments  under any mortgages now existing or hereafter  created by Lessor,  and
Lessor is not and shall not be  required  to render any  services of any kind to
Lessee.


                                      -59-
<PAGE>



         4.   SECURITY DEPOSIT
              ----------------

              (a)  Lessee has,  simultaneously with the execution of this Lease,
deposited  with Lessor,  in cash or by check subject to  collection,  the sum of
eight  thousand  ($8,000.00).  Said  deposit  shall be held as security  for the
faithful  performance  by  Lessee  of  the  terms,  covenants,   provisions  and
conditions  of this  Lease.  It is agreed that in the event  Lessee  defaults in
respect to any of the terms, covenants, provisions and conditions of this Lease,
including (but not limited to) the payment of Base Rent or Additional  Rent, and
fails to cure any such defaults within applicable grace periods, Lessor may use,
apply or  appropriate  the whole or any part of the security so deposited to the
extent  required for the payment of any Base Rent or Additional  Rent or for the
curing of any  defaults by Lessee  hereunder  pursuant to  Paragraph  29 hereof;
provided,  however,  that no such  use,  application,  or  appropriation  of the
deposit shall be deemed to relieve  Lessee of any breach of this Lease and shall
be in addition to other remedies under this Lease.

              (b)  Should  the  entire   deposit  or  any  portion   thereof  be
appropriated and applied by Lessor under the foregoing  provisions,  then Lessee
shall (upon the written demand of Lessor) forthwith remit to Lessor a sufficient
amount in cash to restore  said  security to the  original  sum  deposited,  and
Lessee's  failure  to do so within ten (10) days  after  receipt of such  demand
shall itself constitute an event of default under this Lease.

              (c)  The security deposit (less any amounts applied as provided in
subsection  (a) above) shall be returned to Lessee within thirty (30) days after
the date  fixed as the end of the Term of this  Lease  and  delivery  of  entire
possession of the Leased Premises to Lessor.

              (d)  In the event of a sale, leasing or other transfer of the land
and building of which the Leased  Premises  forms a part,  Lessor shall have the
right to transfer the security and be released by Lessee from all  liability for
the return of such security deposit.  Lessee shall look to the new Lessor solely
for the return of said  deposit.  The  provisions of this  Paragraph  4(d) shall
apply to every  transfer or  assignment  made of the  security  deposit to a new
Lessor.

              (e)  Lessee  covenants  that it will not  assign  or  encumber  or
attempt to assign to encumber  the  security  deposited  herein and that neither
Lessor  nor its  successors  or assigns  shall be bound by any such  assignment,
encumbrance, attempted assignment or attempted encumbrance.

              (f)  Lessee  shall not be entitled to any interest on the security
deposit, and such funds need not be segregated or held as escrow by Lessor.


                                      -60-
<PAGE>



              (g)  It is expressly  understood  and agreed that, in the event of
any  termination  of this  Lease or  re-entry  upon or  reletting  of the Leased
Premises on account of any default on the part of Lessee under this Lease, then,
and in such event, the deposit shall be retained and be subject to appropriation
by Lessor  until this  Lease  would,  by its terms,  have  expired  absent  such
default.

         5.   USE
              ---

              Lessee  will use and  occupy the  Leased  Premises  solely for the
purpose of Offices and operation of a vaccine research and production  facility.
The Leased  Premises  may not be used for any other  purpose  without  the prior
written consent of Lessor, which consent shall not be unreasonably withheld. The
Leased  Premises shall not be used for the storage,  distribution or sale of any
pornographic  or  "adult  rated"  materials.  Lessee  shall  not use the  Leased
Premises for any purpose or activity which is noxious or unreasonably  offensive
because of the emission of noise, smoke, dust,  vibration or odors. Tenant shall
not use the plumbing  facilities for any purpose injurious to same or dispose of
any  garbage or any other  foreign  substance  therein,  nor place a load on any
floor in the Leased  Premises  exceeding  the floor load of 250 per square  foot
which such floor was designed to carry, nor install,  operate and/or maintain in
the Leased  Premises and heavy  equipment  which could cause injury to the Lease
Premises,  nor  install,  operate  and/or  maintain in the Leased  Premises  any
electrical  equipment which will overload the electrical system therein,  or any
part hereof,  beyond its capacity for proper and safe operation as determined by
the Lessor or which does not bear underwriter's  approval.  Lessee shall not use
the Leased  Premises in any manner or for any purpose  which  violates any rule,
regulation, law, ordinance, or requirements of any governmental agency.

         6.   TAXES
              -----

              (a)  As  additional  rent  hereunder,  at least  thirty  (30) days
before  any fine,  penalty  or  interest  or cost may be added  thereto  for the
non-payment  thereof (or sooner if elsewhere herein required),  Lessee shall pay
throughout  the term of this Lease all  levies,  taxes,  assessments,  water and
sewer  rents and  charges,  liens,  charges for public  utilities  and all other
charges,  imposts  or burdens of  whatsoever  kind and nature  which at any time
during the term of this Lease may be assessed or imposed by any  federal,  state
or  municipal  government  or  public  authority,  or under  any law,  ordinance
regulation  thereof or pursuant to any recorded  covenants or agreements (all of
which are hereinafter referred to as "Impositions"), upon or with respect to the
Leased Premises,  any improvements  made thereto,  or this Lease.  Additionally,
Lessee shall pay a  proportionate  share of any Imposition  which is not imposed
upon the Leased Premises as a separate entity but which is imposed upon the land
or the  building  or upon the  appurtenances,  leases,  rents,  transactions  or
documents  relating  to the lot or the  building.  Provided,  however,  that any
Imposition  shall be apportioned for the first and last fiscal tax years covered
by the term hereof.  "Impositions" shall include, but not be limited to, any and
all governmental or  quasi-governmental  levies,  fees,  assessments,  taxes and
charges,  general  and  special,   ordinary  and  extraordinary,   foreseen  and
unforeseen,  of any kind and nature  whatsoever,  with  respect to such land and
building  (excluding  taxes paid on Lessor's  income but including  sales tax or
excise tax imposed by any  governmental  authority upon the Base Rent payable by
Lessee hereunder).


                                      -61-
<PAGE>


              (b)  Notwithstanding  the foregoing  provisions of this Article 6,
Lessor shall have the right,  at its option,  to require Lessee to pay to Lessor
or to any  mortgagee,  at the time when the monthly  installment of Base Rent is
payable,  an amount equal to  one-twelfth  (1/12) of the annual  impositions  as
estimated by Lessor. If Lessor elects to have Lessee make such payments,  Lessee
also  shall  pay to Lessor  or to such  mortgagee,  as the case may be, at least
thirty (30) days before any fine, penalty, interest or cost may be added thereto
for the non-payment  thereof,  the amount by which the impositions  becoming due
exceed the monthly  installment  payments on account thereof  previously made by
Lessee.  Should  Lessee's  monthly  installment  payments on account of Lessee's
share of impositions for any tax year exceed the actual amount of Lessee's share
of such  impositions,  the excess  amount  shall be  credited  against  Lessee's
installments for impositions thereafter becoming due. The amounts paid by Lessee
pursuant to this  paragraph (b) shall be used to pay the  impositions,  but such
amounts  shall not be deemed to be trust funds and no interest  shall be payable
thereon.

              (c)  During any part of the Term of this Lease which shall be less
than a full tax  fiscal  year,  any Taxes  shall be pro  rated on a daily  basis
between  the  parties,  to the end that Lessee only shall pay its share of Taxes
attributable to the portion of the tax fiscal years occurring within the term of
this Lease.

              (d)  Lessee shall pay  promptly,  and when due,  all taxes,  fees,
licenses,  assessments  and other charges levied or imposed upon the business of
the  Tenant  or upon  any  fixtures,  furnishings  or  equipment  in the  Leased
Premises.

              (e)  If due to a future change in the method of taxation or in the
taxing authority,  a franchise,  gross receipts,  transit,  rent or other tax or
other  governmental  imposition,  however  designated,  shall be levied  against
Lessor in  substitution  (in whole or in part)  for,  or in  addition  to,  said
"Impositions"  as  currently  defined),  then such  franchise,  gross  receipts,
transit,  rent or other tax or  governmental  impositions  shall be deemed to be
included within the definition of "Impositions"  for the purposes of this Lease.
The term  "Impositions"  also  includes  all costs  reasonably  incurred  in any
proceeding brought by Lessor to reduce said Taxes.

              (f)  Lessor may  institute  any  proceedings  with  respect to the
assessed valuation of Park Place or any part thereof, and Lessee shall cooperate
with, and participate in, any and all such  proceedings.  If, after Lessee shall
have made the required payment of Taxes hereunder, Lessor shall receive a refund
of any portion thereof,  then, within thirty (30) days after Lessor's receipt of
such refund, Lessor shall pay to Lessee Lessee's pro rata share of the amount of
the  refund,  less all  costs  and  expenses  (including,  but not  limited  to,
attorneys' and appraiser'  fees) expended for incurred in obtaining such refund.
Lessee may not institute any proceedings with respect to the assessed  valuation
of Park Place or any part thereof.


                                      -62-
<PAGE>



         7.   UTILITIES
              ---------

              Starting with the Commencement Date and continuing  throughout the
Term of the Lease,  Lessee shall be solely responsible for and shall pay, as and
when the same  become due and payable and as  hereinafter  provided,  all rents,
rates, costs and charges for water services,  sewer service,  electricity,  gas,
heat, steam, power, telephone (and other communication  services), and any other
utilities or services  rendered or supplied to, upon or in  connection  with, or
used or consumed  within or in  servicing,  the Leased  Premises,  and all other
utility costs and expenses involved in the use of the Leased Premises throughout
the term of this  Lease,  and Lessee  shall  indemnify  Lessor  and save  Lessor
harmless  against  any  costs  liability  or  damages  on such  account.  Unless
otherwise  agreed in writing by Lessor or Lessee,  Lessee  shall,  promptly upon
Delivery of Possession of the Leased  Premises and at Lessee's own expense,  pay
for the  installation of separate meters for all utilities  servicing the Leased
Premises  and place said meters and  related  utility  accounts in Lessee's  own
name.  Lessee shall pay all separately  metered charges to the respective public
utility companies.  With respect to each utility which is not separately metered
for the Leased Premises,  Lessee shall pay Lessor, as Additional Rent,  Lessee's
proportionate  share of the total cost and fees therefore  attributable to those
areas of the warehouse/office buildings which are not separately metered.

         8.   COMMON AREA MAINTENANCE
              -----------------------
               
              (a)  Subject to the  provisions  of this Lease,  Lessor  grants to
Lessee, its employees, agents, customers and invitees during the Term hereof the
non-exclusive use, in common with Lessor and other tenants and occupants of Park
Place and their  respective  employees,  agents,  customers  and invitees and in
common  with such  others  as Lessor  may  designate  from time to time,  of all
non-allocated  parking  areas  within Park Place for  pedestrian  and  vehicular
ingress and egress and the accommodation and parking areas within Park Place for
pedestrian and vehicular  ingress and egress and the  accommodation  and parking
automobiles as required by the Lessee in conducting  normal business  activities
of Lessee within the Leased  Premises.  Lessor reserves the right,  however,  to
designate certain portions of the parking areas within Park Place for parking of
trucks,  vans, and other vehicles,  and to designate for the specific account of
Lessee,  or other  tenants  in Park  Place,  specific  parking  areas or  spaces
constructed with Park Place. Notwithstanding anything contained in this Lease to
the contrary, Lessor shall have the right, at any time and from time to time, to
change the size, location and nature of the parking areas (so long as the number
of parking  spaces is not reduced)  and/or other common areas within Park Place.
All parking areas and related  facilities which may be furnished by Lessor in or
near the Leased Premises,  including  employee parking areas, truck way or ways,
loading docks, pedestrian sidewalks and ramps, landscaped areas, and other areas
and improvements  which may be provided by Lessor for the general use, in common
with Lessor and other tenants, and their respective employees, agents, customers


                                      -63-
<PAGE>



and  invitees,  shall  at all  time be  subject  to the  exclusive  control  and
management  of Lessor,  and Lessor shall have the right,  from time to time,  to
establish,  modify and enforce  reasonable rules and regulations with respect to
all parking areas and other  facilities and areas  mentioned in this  paragraph.
Lessee agrees to abide by and conform with all such rules and  regulations  upon
notice thereof and to cause its employees,  agents, customers and invitees to do
the same.  Lessor shall have no liability to Lessee for use of the parking areas
by Lessor or other  tenants  and  occupants  of Park Place and their  respective
employees, agents, customers, or other third parties. No provision of this Lease
shall be  construed  as a demise to Lessee of the  parking  or any other  common
area) within Park Place.  If any repairs  (excluding  repairs caused by Lessee's
normal  use) to the  parking  or  other  common  areas  within  Park  Place  are
necessitated  by reason  of any act or  omission  by  Lessee  or its  employees,
agents, customers or invitees, then, if Lessor chooses to do so, Lessor may make
such repairs and Lessee shall promptly upon demand reimburse Lessor for the full
costs to the extent same are not covered by Lessor's  insurance,  or at Lessor's
option,  Lessor may notify Lessee of the necessity for such repairs, and Lessee,
at its cost and expense,  shall,  with due  diligence,  commence and complete to
Lessor's  satisfaction  the repairs within ten (10) days of Lessee's  receipt of
such notice.

              (b)  "Common  Area  Charges"  means all of the costs and  expenses
which are incurred by Lessor with respect to operation, management,  maintenance
and security of the building  including the parking and other designated  common
areas in Park Place and the exterior  walls of the buildings in Park Place,  and
those areas of Park Place which house mechanical,  electrical or other equipment
or are otherwise  determined from time to time by Lessor to be used in operating
or maintaining Park Place.  "Common Area Charges"  include,  but are not limited
to,  the cost of  maintaining,  repairing,  and  replacing  and  repaving  (when
necessary) the parking and other designated  common areas;  supplies,  tools and
materials  purchased and/or used in connection with repairs,  maintenance and/or
replacements;  wages,  salaries,  and fringe  benefits of all  employees  of the
Lessor for the  portion  of time they are  directly  engaged  in the  operation,
maintenance  and  security  of Park  Place,  including  license  and  fees  (but
excluding wages, salaries and benefits of executive  employees);  removing snow,
ice,  and debris from the  roadways  and parking  areas for  Lessee's use during
normal  business hours;  removal of customary and normal trash;  maintaining and
repairing or repainting (when necessary)  directional signs,  pavement markings,
and parking lot  striping;  repairing  and replacing  (when  necessary)  outdoor
lighting  facilities;  maintaining  the  grass  and  otherwise  caring  for  the
replanting (when  necessary) all shrubbery and landscape  areas;  providing such
security as Lessor,  in its sole  discretion,  deems  advisable;  accounting and
legal fees for common areas at Park Place; utilities,  heating,  ventilation and
air-conditioning charges allocable to designated common areas and other building
service areas.


                                      -64-
<PAGE>



              (c)  Starting with the Commencement Date and continuing throughout
the Terms of this  Lease,  Lessee  shall pay Lessor in  advance  as  hereinafter
described and as Additional  Rent,  Lessee's  Pro-Rata  Share of all Common Area
Charges for said period.  "Lessee's  Pro-Rata  Share"  shall be a fraction,  the
numerator  of which shall be the floor area within the Leased  Premises  and the
denominator  of which shall be the total floor area within all buildings in Park
Place. The Initial Lessee's Pro-Rata Share shall be 4.50%. 

         The  Company  is, and from time to time  becomes,  involved  in various
claims and lawsuits that are  incidental to its business.  In the opinion of the
Company's  management,  there are no material legal proceedings  pending against
the Company.

              (d)  On or before the  Commencement  Date, on or before the end of
each and every Lease year,  and at such other time(s) as is deemed  desirable by
lessor in its sole  discretion,  Lessor  shall  forward to Lessee a "Common Area
Charges  Statement",  which shall contain Lessor's latest estimate of the Common
Area  Charges  for the then  current or the then  upcoming  (as the case may be)
Lease Year,  and a statement  of Lessee's  Pro-Rata  Share  thereof.  Landlord's
failure to forward,  or to timely  forward,  any Common Area  Charges  Statement
shall not excuse Lessee from its liability for Lessee's Pro-Rata Share of Common
Area Charges.

              (e)  Each  month  during the Term of this  Lease,  along with each
monthly  installment of Base Rent,  beginning with the Commencement Date, Lessee
shall pay to Lessor,  in advance,  an amount  equal to  one-twelfth  (1/12th) of
Lessee's  Pro-Rata  Share of the  Common  Area  Charges as set forth in the then
latest Statement.  If the Commencement Date is a day other than the first day of
a calendar month, then the amount of Common Area Charges due for the first month
and the last month of the Term shall be pro rated on the basis of a thirty  (30)
day month. As soon as practicable near the end of each and every Lease Year, but
no later than 90 days after the end of the Lease year,  Lessor  shall  submit to
Lessee an "Actual Common Area Charges Statement" prepared by Lessor showing that
the Common Area Charges for the then preceding  Lease Year actually  were.  With
the next monthly  installment  of Base Rent due after  Lessee's  receipt of such
Statement,  Lessee shall pay Lessor or Lessor shall credit  Lessee,  as the case
may be the difference  between Lessee's Pro-Rata Share of the actual Common Area
Charges  for said  Lease  Year as shown on said  Statement  and the total of all
Common Area Charges paid by Lessee to Lessor for said Lease Year.

         9.   NON-LIABILITY OF LESSOR
              -----------------------

              (a)  Except  as  otherwise  expressly  provided  in this  Lease or
unless caused by the negligence or intentional  misconduct of Lessor or Lessor's
employees,  agents  and  contractors  while  acting  within  the  scope of their


                                      -65-
<PAGE>



employment,  Lessor shall not be responsible or liable to Lessee for any loss or
damage to persons or property,  or any  interference or interruption of Lessee's
use of the Leased  Premises,  that may be occasioned by (i) water,  gas,  steam,
wind or the bursting, stoppage or leaking of any pipes, sewer or water lines, or
other  conduits,  fixtures or equipment;  (ii) the  interruption  of any utility
services  to the  Leased  Premises  caused  by the  utility  company;  (iii) any
repairs,  alterations,  maintenance or additions to the Leased  Premises or land
and  building of which they are a part;  (iv) any  casualty;  (v) theft or other
criminal  conduct;  or (vi) the acts or omissions of persons occupying any space
adjacent to the Leased Premises.

              (b)  No provisions of this  Lease  shall be deemed to confer  any
rights  upon any  persons  or  entities  other than the  parties to this  Lease,
permitted successors and assigns and mortgages.

              (c)  Notwithstanding  anything  to the  contrary  provided in this
Lease, it is  specifically  understood and agreed that there shall be absolutely
no personal  liability on the part of Lessor,  including  partners in Lessor and
their  respective  successors  and assigns,  with respect to its  performance or
observance of any of the terms, covenants and conditions of this Lease, and that
Lessee shall look solely to the equity of the Lessor in the land and building of
which the Leased  Premises  form a part for the  satisfaction  of each and every
remedy  of Lessee  in the  event of any  breach  by Lessor of any of the  terms,
covenants  and  conditions  of this Lease to be performed or observed by Lessor,
such exculpation of personal  liability to be absolute and without any exception
whatsoever.

              (d)  If  Lessor  shall  fail  to  comply  fully  with  any  of its
obligations under this Lease,  Lessee may seek and enforce specific  performance
of the Lease against Lessor and pursue such other  equitable  remedies as may be
available to Lessee.  Notwithstanding  the foregoing,  the result of such action
shall be subject to the provisions of Paragraph 9(c) hereof.

         10.  INDEMNITY
              ---------

              Lessee  agrees to  indemnify  and save  Lessor  harmless  from and
against any and all claims,  demands,  costs and  expenses  (including,  but not
limited  to,  reasonable  attorneys'  fees  and  litigation  costs)  for,  or in


                                      -66-
<PAGE>



connection  with,  any  accident,  injury or damage  whatsoever to any person or
property (i) arising directly or indirectly out of Lessee's use of occupation of
the Leased  Premises,  (ii) occurring in, on or about the Leased  Premises or on
the sidewalks  adjoining the same, or (iii) arising  directly or indirectly from
any act or  omission of Lessee or any of Lessee's  licenses,  servants,  agents,
employees or  contractors.  The foregoing  indemnity shall not apply to any such
claim or demand proximately caused by the negligence or misconduct of Lessor, or
its  employees,  agents and  contractors  while acting within the scope of their
employment.

         11.  LIABILITY INSURANCE
              -------------------

              (a)  Lessee,  at Lessee's sole expense,  shall obtain and maintain
in  effect at all  times  starting  with the  Commencement  Date and  continuing
throughout the term of the Lease, a policy or policies of comprehensive  general
public liability insurance,  insuring Lessor,  Lessor's  mortgagee(s) and Lessee
against any liability for injury, death or property damage occurring upon, in or
about any part of the Leased Premises or any  appurtenances  thereto,  affording
protection  to the limits of not less than One Million  Dollars  ($1,000,000.00)
with  respect  to bodily  injury or death of any one  person,  and not less than
Three Million Dollars  ($3,000,000.00) with respect to any one incident, and not
less than Five Hundred Thousand Dollars  ($500,000.00)  with respect to property
damage.  The foregoing  minimum  limits may, at Lessor's  option and upon thirty
(30) days' notice to Lessee, be increased from time to time to reflect inflation
or changed conditions.

              (b)  The insurance  policy(ies)  required to be procured by Lessee
under this Lease:

                  (i)    Shall  be  issued  by  a  reputable  insurance  company
licensed to do  business  in the State of Maryland  and shall have such form and
content as shall be approved by Lessor.

                  (ii)   Shall be  written as primary  policy  coverage  and not
contributing with, or in excess of, any coverage which Lessor may carry.

                  (iii)  Shall have an endorsement thereto to the effect that no
act or  omission by Lessee  shall  affect the  obligation  of the insurer to pay
Lessor the full  amount of any loss  sustained  by Lessor  and shall  contain an
express  waiver of any right of  subrogation  by the insurance  company  against
Lessor, its agents and employees.

                   (iv)  Shall name Lessor as an additional named insured.

              (c)  On or before the Commencement Date, and at least fifteen (15)
days before the expiration date of the policy,  Lessee shall deliver to Lessor a
certificate  of insurance  evidencing  the  existence  and good  standing of the
liability  policy  referred to in Paragraph  11(a),  together  with  evidence of
payment of all premiums.  The insurance  required to be carried under this Lease
may be carried  under a blanket  policy  covering the Leased  Premises and other
locations of Lessee. The insurance policy required to be carried by Lessee shall
provide  that such  insurance  policy  shall not be canceled  unless  Lessor and


                                      -67-
<PAGE>




Lessor's  mortgage(s) shall have received thirty (30) days' prior written notice
of cancellation.  In the event that Lessee shall,  prior to the thirtieth (30th)
day  before  any  insurance  policy  will  lapse or  terminate,  fail to furnish
evidence of the coverage and pay the premium therefor for a period not exceeding
one year,  and the  premiums  so paid by Lessor  shall be payable by Lessee,  on
demand, as Additional Rent.

         12.  HAZARD INSURANCE
              ----------------

              (a)  Starting with the Commencement Date and continuing throughout
the Term of this  Lease,  Lessee  shall pay to Lessor,  or such  other  party as
Lessor shall designate by written notice to Lessee, as Additional Rent, Lessee's
Pro-Rata Share, as defined in Paragraph 12(e) hereof,  of the premiums and other
charges (the "Premiums") that may be incurred or contracted for or by Lessor for
fire and casualty  insurance  coverage  for the land and  buildings of which the
Leased  Premises form a part,  including  protection  from such perils as may be
insured against under a broad form extended coverage  endorsement or on all risk
of physical loss policy,  and further  including  loss of rental  coverage in an
amount equal to the Rent for one (1) Lease Year.  The premiums for all insurance
to be  obtained  by  Lessor  under  this  Paragraph  12(a)  shall be  reasonably
competitive  with the  premiums  charged for  similar  insurance  protection  by
reputable  insurers for  comparable  properties.  Lessee agrees that it will not
store  gasoline or other  explosive,  flammable or toxic  material in the Leased
Premises or do anything which may cause Lessor's  insurance  company to void the
policy covering the Leased Premises or to increase the premium thereon, and that
Lessee will  immediately  conform to all rules and regulations from time to time
made or established by Lessor's  insurance  company or insurance  rating bureau.
Lessor will do everything reasonably possible and consistent with the conduct of
Lessee's  business  to obtain the lowest  possible  rates for  insurance  on the
Leased Premises.  If, however,  the cost to Lessor of obtaining insurance on the
Leased  Premises  (or the  building  which the Leased  Premises  are located) is
increased  due to the  Lessee's  occupancy  thereof,  and the  Lessor's  insurer
provides evidence that said increase is the direct cause of Lessee's  occupancy,
Lessee agrees to pay,  promptly  upon demand,  as  additional  rental,  any such
increase.

              (b)  On or before the Commencement Date and before the due date of
each and  every  bill for the  Premiums,  Lessor  shall  forward  to  Lessee  an
"Insurance  Statement" which shall contain an estimated  statement of the amount
due from Lessee from time to time as Lessee's  Pro-Rata  Share of the  Premiums.
Lessor's failure to forward, or to timely forward, any Insurance Statement shall
not  excuse  Lessee  from  its  liability  for  Lessee's  Pro-Rata  Share of the
Premiums.


                                      -68-
<PAGE>



              (c)  Each and every  month  during the Term of this  Lease,  along
with its monthly installment of Fixed Rent,  beginning on the Commencement Date,
Lessee  shall pay  Lessor  an amount  equal to  one-twelfth  (1/12) of  Lessee's
Pro-Rata  Share  of the  Premiums  as set  forth in the  then  latest  Insurance
Statement,  which  shall  be  credited  toward  Lessee's  Pro-Rata  Share of the
Premiums when the same are due and payable.  Should Lessee's monthly installment
payments on account of Lessee's Pro-Rata Share of the Premiums for the period to
which the Premiums relate exceed the actual amount of Lessee's Pro Rata Share of
such Premiums, the excess amount shall be credited against Lessee's installments
for Premiums thereafter becoming due. If the Commencement Date is other than the
first day of a period to which the Premiums relate, then the installments of the
Premiums  due from the Lessee  shall be pro rated on the basis of a thirty  (30)
day month.

              (d)  Notwithstanding  the  provisions  of  Paragraph  12(c) above,
Lessor may, upon ten (10) days' written notice to Lessee,  require Lessee to pay
Lessee's  Pro- Rata Share of the  necessary  increased  Premiums due to Lessee's
occupancy at such times as the  Premiums  are due and payable to the  respective
insurance  company or companies or in such manner as is required of Lessor under
any mortgage, whether such payments be in lump sum or other installments.

              (e)  Lessee's  Pro-Rata  of  the  Premiums  shall  be of  all  the
Premiums due for the land and building of which the Leased Premises form a part.
As used in this Paragraph 12, "Lessee's Pro Rata Share" shall be a fraction, the
numerator  of which shall be the floor area within the Leased  Premises  and the
denominator  of which shall be the total floor area within the building of which
the Leased Premises form a part.

              (f)  Lessor  hereby   releases   Lessee  from  any  liability  and
responsibility  to Lessor to anyone  claiming  through or under Lessor by way of
subrogation or otherwise,  for any and all loss or damage to the Leased Premises
caused by fire or any  casualty  covered by  insurance  to the extent  insurance
proceeds are received  therefor,  even if such fire or other casualty shall have
been caused by the fault or negligence of Lessee,  or anyone for whom Lessee may
have been responsible.  Lessor's  insurance  policies shall include  appropriate
clauses (i) waiving all rights of  subrogation  against  Lessee with  respect to
losses payable under such  policies,  and (ii) agreeing that such policies shall
not be  invalidated  should the insured waive in writing prior to a loss any and
all rights of recovery against the other party hereto for losses covered by such
policies.

         13.  DAMAGE TO THE DEMISED PREMISES
              ------------------------------

              (a)  In the event of partial or total damage or destruction of the
Leased  Premises  by fire,  other  casualty,  or any  cause  whatsoever  (except
condemnation),  Lessee shall give immediate  notice to Lessor.  If the damage or


                                      -69-
<PAGE>


destruction  is insured  against by Lessor,  this Lease  shall  continue in full
force and effect,  and, to the extent that insurance  proceeds  respecting  such
damage or  destruction  are  subject  to being  utilized  and,  in fact,  may be
utilized by Lessor for repair,  Lessor shall cause such damage or destruction to
be repaired with reasonable speed at the expense of Lessor,  except as otherwise
hereinafter  provided  in this  Paragraph  13. If in the  reasonable  opinion of
Lessor the damage or destruction  is such that repair thereof cannot  reasonably
be  completed  within  ninety  (90) days of the date the  damage or  destruction
occurs,  Lessor  shall have the right to  terminate  this Lease by the giving of
written  notice to such effect to Lessee  within thirty (30) days of the date of
Lessor's receipt of Lessee's notice of damage or destruction.  In no event shall
Lessor be  required  to restore or repair  Lessee's  personal  property or other
contents within the Leased Premises.  Due allowance shall be made for reasonable
delay which may arise by reason of Lessor's  adjustment of loss under  insurance
policies  and on account of labor  troubles or any other cause  beyond  Lessor's
control. To the extent that the Leased Premises are rendered  untenantable,  the
Rent  and  Additional  Rent  shall  proportionately  abate.  If  the  damage  or
destruction  is not covered by  insurance  maintained  by Lessor or if insurance
proceeds  respecting the damage or destruction are not subject to being utilized
for repair and, in fact, may be not so utilized, Lessor shall not be required to
repair the damage or  destruction.  In the event the damage or destruction is so
extensive to the  building of which the Leased  Premises are a part as to render
it uneconomical, in Lessor's opinion, to restore the Leased Premises, the Lease,
at the option of Lessor,  shall be terminated  upon written notice to Lessee and
Lessee shall immediately thereafter vacate the Leased Premises and surrender the
same to Lessor.  No such termination  shall release Lessee from any liability to
Lessor from any of the  obligations or duties imposed on Lessee under this Lease
prior  to the  damage.  Upon  any  termination  of this  Lease  pursuant  to his
Paragraph 13(a),  Rent and Additional Rent shall be prorated and adjusted to the
date of such termination.

              (b)  Lessee hereby  waives any and all right of recovery  which it
might  otherwise  have against  Lessor,  its agents and  employees,  for loss or
damage to Lessee's contents, furniture, furnishings, fixtures and other property
removable  by Lessee under the  provisions  of this Lease to the extent that the
same is to be covered by Lessee's insurance  thereunder,  except where such loss
or damage  may  result  from the  negligence  of fault of  Lessor,  its  agents,
employees or contractors.

         14.  EMINENT DOMAIN
              --------------

              (a)  If during the term of this  Lease,  the Leased  Premises,  or
such a substantial  portion of the Leased  Premises as shall prevent Lessee from
conducting its normal business, shall be taken by proper authority for public or


                                      -70-
<PAGE>



quasi-public  use, then Lessee may terminate this Lease by giving Lessor written
notice of  termination  within  thirty (30) days after  receipt of notice of the
taking,  and Lessee's  obligation  to pay rent,  taxes,  and other charges shall
terminate as of the date of the termination notice. If only a part of the Leased
Premises is taken and the part not taken shall be reasonably  sufficient for the
purpose of conducting Lessee's normal business,  this Lease shall remain in full
force  and  effect,   except  that  the  Rent  and  Additional   Rent  shall  be
proportionately reduced.

              (b)  All  compensation  awarded for any taking shall belong to and
be the property of Lessor. Nothing contained herein, however, shall be construed
to preclude Lessee from  prosecuting  any claim directly  against the condemning
authority  for loss of  business or  depreciation,  damage or cost of removal of
personal property  belonging to Lessee so long as the claim does not diminish or
otherwise  adversely  affect  Lessor's award or the award  otherwise  payable to
Lessor's mortgagee.

         15.  CONDITION OF LEASED PREMISES; MAINTENANCE AND REPAIR
              ----------------------------------------------------

              (a)  Except for the repairs that Lessor is specifically  obligated
to make  under  Paragraph  15(b)  hereof,  and  except  for  repairs  covered by
contractor  warranties held by Lessor for Lessor's  benefit,  during the term of
this Lease,  Lessee, at Lessee's sole cost and expense,  shall promptly make all
repairs,  perform all maintenance,  perform all custodial  services and make all
replacements  in and to the Lease  Premises  that are necessary in order to keep
the  Leased  Premises  in good  order and  repair  and in a safe and  tenantable
condition. Without limiting the generality of the foregoing, Lessee, at its sole
cost and expense,  is specifically  required to make promptly all repairs to (i)
any pipes,  water and waste lines,  ducts,  wires or conduits  beneath or in the
Leased  Premises  or within the ceiling of the Leased  Premises;  (ii) any glass
windows included within the Leased Premises;  (iii) Leasee's  sign(s);  (iv) any
electrical,  natural gas (if any),  heating,  ventilating and air  conditioning,
plumbing,  and other  systems,  equipment,  fixtures  and items  installed in or
servicing the Leased Premises; (v) the floors,  ceilings and walls of the Leased
Premises;  (vi) the entrance and exit and auxiliary driveways, if any, which are
part of and  service  the Leased  Premises;  and (vii) any portion of the Leased
Premises  damaged by Lessee's use or occupancy of the Leased  Premises or by any
act,  omission or  negligence  of Lessee,  or any of its  respective  employees,
agents, invitees,  licensees or contractors.  All repairs, and replacements made
by Lessee shall  utilize  materials  and  equipment  which are at least equal in
quality and usefulness to those originally used in the Leased Premises.  Lessee,
at Lessee's expense,  shall enter into one (1) or more service contracts for the
maintenance  of the  heating,  ventilating  and  air  conditioning  systems  and
equipment.  Lessee shall keep the Leased Premises free of all insects,  rodents,
vermin and pests of every type and kind. Lessee shall also,  promptly and at its
own expense,  keep any sidewalks and curbs adjacent to the Leased Premises clean
and free from snow,  ice,  dirt and rubbish.  Lessee  shall not  (directly or by
sufferance)  place any equipment,  materials or debris on the roof of the Leased
Premises, or cut, drive nails into or otherwise mutilate such roof.


                                      -71-
<PAGE>



              (b)  Lessor shall within  thirty (30) days (or such longer  period
of time as may  reasonably  be required  by Lessor)  after  written  notice from
Lessee with respect thereto,  make necessary  structural repairs to the exterior
walls  and  shall  keep  in  good  order,  condition  and  repair  the  exterior
foundations, downspouts, gutters and roof of the Leased Premises and the portion
of the  plumbing  and sewage  system  located  outside the building in which the
Leased  Premises  are located (it being  understood  and agreed that  Landlord's
obligations exclude the exterior and interior of all windows, doors, plate glass
and signs, and repairs  required by any casualty except as otherwise  covered by
Paragraph 13 herein). Lessee shall, upon demand, reimburse Lessor for reasonable
costs of making  any such  repairs or  replacements  caused by  Lessee's  use or
occupancy  of the Leased  Premises  or by any act,  omission  or  negligence  of
Lessee,   any  subtenant  or  concessionaire  of  Lessee,  or  their  respective
employees,  agents,  invitees,  licensees or contractors  (excluding  repairs or
replacements caused by Lessee's normal use).

              (c)  Lessee  hereby  covenants  to contain all  garbage,  rubbish,
waste,  trash and debris  generated  in  conjunction  with its use of the Leased
Premises in  containers  provided by Lessor (which shall be emptied no more than
three times per week, but at least once a week) so as not to constitute a safety
or fire hazard.

         16.  ALTERATIONS
              -----------

         Lessee  shall  not  make  any  non-structural   interior   alterations,
additions or improvements in or to the Leased Premises without the prior written
consent of Lessor in each  instance,  which  consent  shall not be  unreasonably
withheld  or  delayed.   Lessee  shall  not  take  any  structural  or  exterior
alterations,  additions or improvements to the Leased Premises without the prior
written  consent of Lessor.  Should Lessor fail to respond  within  fifteen (15)
working  days after  Lessor's  receipt of any  written  request  from Lessee for
Lessor's  consent  to  any  proposed  alterations,  additions  or  improvements,
Lessor's   consent  shall  be  deemed  to  have  been  granted.   All  permitted
alterations, additions and improvements made by Lessee shall be performed (i) in
a good and workmanlike  manner, (ii) in accordance with all applicable legal and
insurance  requirements,  (iii) only after receipt by Lessee and presentation to
Lessor of all necessary permits and licenses, and (iv) at Lessee's sole expense.
Except for Lessee's removable trade fixtures, and all improvement made by Tenant
in the processing and storage areas, all improvements,  repairs, alterations and
additions and all other non-trade  fixtures,  whether  installed before or after
the  execution  of this  Lease,  shall  remain  upon the Leased  Premises at the
expiration or sooner termination of this Lease and become the property of Lessor
without  payment  therefor by Lessor,  unless prior to the  termination  of this
Lease,  Lessor shall have given written  notice to Lessee to remove the same, in
which event Lessee, at its expense, will remove such alterations,  improvements,
additions  and/or  fixtures  and  repair and  restore  any and all damage to the
Leased Premises caused by the installation and/or removal thereof.


                                      -72-
<PAGE>



         17.  SIGNS
              -----

              Lessee may not install any sign  without  Lessor's  prior  written
consent.  All signs shall be in strict  compliance  with the sign  criteria  set
forth in Exhibit "C" attached hereto and made part hereof.  Lessee shall install
all exterior signs for the Leased Premises at the cost and expense of Lessee. No
sign, advertisement or notice shall be inscribed,  painted, affixed or otherwise
displayed on any part of the outside or the inside of the Leased Premises or the
building  of which the Leased  Premises  are a part,  unless  Lessor  shall have
approved the sign, advertisement,  or notice in writing prior to installation of
the same. If any sign,  advertisement,  or notice is exhibited by Lessee without
having first obtained Lessor's approval thereof,  Lessor shall have the right to
remove the same and Lessee shall be liable for any and all expenses  incurred by
Lessor in said  removal.  No signs made of paper and visible from outside of the
Leased Premises shall be allowed in the Leased Premises. No mobile sign, such as
may be affixed to the side of a truck or a trailer or a mobile platform shall be
permitted in the parking area.

         18.  LAWS AND INSURANCE STANDARDS
              ----------------------------

              Lessee shall,  at Lessee's sole expense,  promptly comply in every
respect with all  applicable  laws,  ordinances,  rules and  regulations  of all
federal,  state,  county, and municipal  governments now in force or that may be
enacted in the future,  all applicable  and  enforcement  directions,  rules and
regulations of the fire marshall,  health officer,  building  inspector or other
proper  officers  of  any  governmental  agency  having  jurisdiction,  and  the
applicable standards established from time to time by the National Board of Fire
Underwriters,  the National Fire Protective Association,  or any similar bodies.
Lessee expressly covenants and agrees to indemnify and save Lessor harmless from
any  penalties,  damages or charges  imposed for any violation of the foregoing.
Notwithstanding the foregoing,  Lessee shall not be required to make any changes
or modifications to the Leased Premises, unless (a) the same are required due to
Lessee's specific use and/or occupancy of the Leased Premises,  (b) the same are
required due to structural specifications (beyond building standard) required by
Lessee, or (c) the same relate to repairs, maintenance or other responsibilities
of Lessee under this Lease, e.g., Paragraph 15(a) hereof.

         19.  MECHANIC'S LIENS
              ----------------

              Lessee shall do all things  necessary to prevent the filing of any
mechanics' or other liens against the Leased Premises,  or the land the building
of which the Leased  Premises are part,  by reason of work,  labor,  services or
materials  supplied or claimed to have been supplied to Lessee or anyone holding
the Leased Premises,  through or under Lessee.  If any lien shall at any time be


                                      -73-
<PAGE>



filed,  Lessee shall either cause the lien to be discharged of record within ten
(10) days after knowledge of its filing or, if Lessee in its discretion and good
faith determines that the lien should be contested,  shall furnish such security
as may be necessary to prevent the filing of any foreclosure  proceedings during
the pendency of the contest.  If Lessee shall fail to discharge  any lien within
such period or fail to furnish  such  security,  then,  in addition to any other
right or remedy,  Lessor may, but shall not be obligated to,  discharge the same
either by paying the amount  claimed to be due or by procuring  the discharge of
lien by deposit in court or by giving  security or in such other manner as is or
may be  prescribed  by law.  Lessee  shall  repay to Lessor  on demand  all sums
disbursed or deposited by Lessor pursuant to the foregoing provisions, including
the  expenses  and  reasonable  attorneys'  fees  incurred  by  Lessor.  Nothing
contained  in this Lease shall imply that  Lessee has any  authority  or consent
from Lessor to subject Lessor's estate to any mechanics', materialman's or other
lien.

         20.  ASSIGNMENT AND SUBLETTING
              -------------------------

              (a)  Lessee shall not assign, mortgage or encumber any interest in
this Lease or sublet all or any part of the Leased  Premises  without  the prior
written consent of Lessor.  Lessor shall not unreasonably  withhold or delay its
consent to an assignment or subletting of this Lease.

              (b)  No  permitted   assignment  or  subletting   shall   release,
discharge or affect the liabilities of Lessee as provided for in this Lease, and
Lessee  shall  at all  times  remain  primarily  liable  under  this  Lease.  An
assignment  by operation of law shall be deemed a  prohibited  assignment  under
this Paragraph.

         21.  INSOLVENCY
              ----------

              Lessor may,  at its option,  declare  this Lessee  terminated  and
reenter  and  resume  possession  of the  Leased  Premises,  if Lessee  shall be
adjudicated  a  bankrupt  or  insolvent,  or if a receiver  or trustee  shall be
appointed for Lessee's business or property,  or if Lessee shall file a petition
in bankruptcy or insolvency, or if a petition or other proceeding shall be filed
by or against Lessee seeking corporate or other  reorganization,  liquidation or
other similar relief or if Lessee shall make an assignment or an arrangement for
the benefit of creditors,  or if an involuntary  petition shall be filed against
Lessee in  bankruptcy or  insolvency  and such  petition  shall not be dismissed
within sixty (60) days.


                                      -74-
<PAGE>


         22.  REMEDIES CUMULATIVE
              -------------------

              The various rights,  elections and remedies of Lessor contained in
this  Lease  shall  be  cumulative,  and no one of them  shall be  construed  as
exclusive of any of the others,  or of any right,  priority or remedy allowed or
provided for by law.

         23.  WAIVER OR DEFAULT
              -----------------

              The waiver by either  party of any default in the  performance  by
the other of any covenant shall not be construed to be a waiver of any preceding
or subsequent  default of the same or any other covenant  contained herein.  The
subsequent  acceptance  of Rent or other  sums by  Lessor  shall not be deemed a
waiver of any  preceding  default  other  than the  failure of Lessee to pay the
particular rental or other sum so accepted.

         24.  HOLDING OVER
              ------------

              If Lessee shall hold  possession of the Leased  Premises after the
end of the term or other termination of this Lease, Leases shall be deemed to be
occupying the Leased Premises as a tenant from month to month, subject to all of
the  conditions,  provisions and obligations of this Lease;  provided,  however,
Lessee  shall be liable for any and all  damages  and  expense  that  Lessor may
sustain by virtue of Lessee's holding over,  including,  but not limited to, any
amount for which Lessor may be liable under,  or as a result of, any other lease
entered into by Lessor for a term  beginning at or after the  expiration  of the
term of this Lease.  Nothing  contained  in this Lease shall be  construed  as a
consent by Lessor to the  occupancy  or  possession  of the Leased  Premises  by
Lessee after the expiration of the term of this Lease. Rather, at the end of the
term of the  Lease,  Lessor  shall be  entitled  to the  benefit  of all laws or
ordinances  relating to the recovery of the  possession  of lands and  tenements
held over by tenants that now may be in force or hereafter  may be enacted,  and
Lessor may proceed under such laws or ordinances,  without notice to Lessee, all
statutory notice requirements being expressly waived by Lessee.

         25.  SURRENDER
              ---------

              Upon the expiration of the term of this Lease,  Lessee immediately
shall surrender the Leased Premises broom-clean and in good order and condition,
ordinary wear and tear excepted.  All of Lessee's  personal property at or about
the Leased Premises (but not permanently  affixed parts of the Leased  Premises)
shall be removed by Lessee at or before the expiration of this Lease or shall be
deemed  abandoned by Lessee.  Any damage to the Leased  Premises  caused by such
removal shall be repaired by Lessee at its own expense.

         26.  DEFAULT
              -------

              (a) If Lessee  fails to pay any Rent or  Additional  Rent when due
and such failure continues for a period of five (5) days after Lessor shall have
made written demand on Lessee for payment, or if Lessee otherwise is at any time


                                      -75-
<PAGE>



in default under this Lease and continues in such default for a period of thirty
(30) days after  Lessor  shall  have  demanded  in  writing to Lessee  that such
default be cured, or if such latter default is not capable of being cured within
a fifteen (15) day period,  such additional time (not to exceed  forty-five (45)
days) as is reasonably necessary to cure such default,  provided Lessee promptly
commences  and  diligently  pursues to cure such  default,  then  Lessor may, at
Lessor's  option,  terminate this Lease (without  releasing Lessee of liability)
and by summary  proceedings or other manner  prescribed by law, reenter and take
possession of the Leased  Premises.  If Lessor  should so terminate  this Lease,
Lessee  shall pay to Lessor as damages,  upon demand,  all expenses  (including,
without limitation,  attorneys' fees) of any proceedings  necessary in order for
Lessor  to  recover  possession  of the  Leased  Premises  and the  expenses  of
reletting  the  Leased  Premises  (including,  without  limitation,   reasonable
attorneys'  fees,  brokerage  commissions,  and the costs of putting  the Leaded
Premises in good order and preparing it for reletting, plus either:

                   (i)   Liquidated damages in an amount equal to the excess, if
any,  of the Rent and  Additional  Rent that  would have been  payable  over the
unexpired  portion of the term of this Lease over the rental value of the Leased
Premises for such unexpired  portion of the term of this Lease, as discounted at
the  then  publicly  declared  prime  rate of the  Federal  Bank  in  Baltimore,
Maryland; or

                   (ii)  Damages  in an amount  to the  excess,  if any,  of the
monthly  Rent and  Additional  Rent over the  monthly  rentals,  if any, if fact
collected by Lessor as the result of a reletting of the Leased  Premises at such
rent and upon such terms as Lessor,  in its sole  discretion,  elects to accept.
Separate  actions may be maintained  each month by Lessor to recover the damages
then due as provided for in this subparagraph (ii) and any such action shall not
prejudice the rights of Lessor to collect damages for any subsequent  month in a
similar proceeding.

              (b)  No re-entry or reletting of the Leased  Premises,  whether or
not the term of such reletting  extends beyond the term of this Lease,  shall be
construed  as an  election  by Lessor to: (i) accept a  surrender  of the Leased
Premises, or (ii) release Lessee of any of its obligations under this Lease.

              (c)  Should Lessor,  pursuant to its rights under  Paragraph 26(a)
hereof,  elect to terminate  this Lease and reenter and take  possession  of the
Leased Premises,  Lessor shall use commercially  reasonable efforts,  under then
prevailing circumstances, to relet the Leased Premises.

         27.  ACCESS TO LEASED PREMISES
              -------------------------

              (a)  Lessor and its  designees  shall have the right  (subject  to
being accompanied by Lessee's  representative at all times for security reasons)
to enter  upon the  Leased  Premises  at all  reasonable  hours,  after 24 hours
notice,  (and in  emergencies,  at all times):  (i) to inspect the same; (ii) to


                                      -76-
<PAGE>



make repairs,  additions,  or alterations to the Leased Premises or the building
in which the same are located or any property  owned or  controlled by Landlord;
(iii) to  exhibit  the  Leased  Premises  to any  prospective  buyer,  lessee or
mortgagee or their respective agents or representatives; and (iv) for any lawful
purpose.

              (b)  For a period  commencing three (3) months prior to the end of
the term,  Lessor may have reasonable  access to the Premises for the purpose of
exhibiting  the same to  prospective  tenants and to post any "For Rent" or "For
Lease" signs upon the Leased Premises.

         28.  SUBORDINATION AND ATTORNMENT
              ----------------------------

              (a)  This  Lease is  subject  and  subordinate  to the lien of all
present  and  future  mortgages  and/or  deeds of trust  encumbering  the Leased
Premises,  all present and future advances under such mortgages  and/or deeds of
trust, and all renewals, extensions,  modifications,  recastings or refinancings
of such  mortgages  and/or deeds of trust.  Lessee agrees that, in the event any
proceedings are brought under or for the foreclosure of any such mortgage and/or
deed of trust,  Lessee shall, if requested to do so by the beneficiary  under or
holder of such mortgage  and/or deed of trust or by any successor in interest to
such beneficiary or holder, automatically become the lessee of such beneficiary,
holder  or  successor  in  interest  and  shall  automatically  attorn  to  such
beneficiary, holder and/or successor in interest and recognize such beneficiary,
holder  and/or  successor  in  interest  as the  Lessor  under  this  Lease.  In
confirmation of such attornment, however, Lessee shall, at the request of Lessor
or any  beneficiary,  holder or  successor  in  interest,  promptly  execute any
requisite or  appropriate  certificate or other document for the benefit of such
beneficiary, holder and/or successor in interest.

              (b)  In the event that,  after the date of this Lease, a bona fide
loan shall be made by an insurance company, savings bank, commercial bank, trust
company, or other lender and secured by a mortgage or deed of trust constituting
a lien  against  any  portion  of the  Leased  Premises  and said  lender  shall
complete,   execute   and   acknowledge   a   subordination,   attornment,   and
non-disturbance agreement, then and in that event, Lessee shall subordinate this
Lease to said mortgage or deed of trust by executing and  acknowledging the said
subordination, attornment and non-disturbance agreement.

              (c)  Upon any assignment or  termination  of Lessor's  interest in
the Leased Premises,  Lessee shall,  upon request,  attorn in writing to the new
owner of the Leased  Premises and shall pay to the new owner all rents and other
monies  required to be paid and perform all of the other  obligations  of Lessee
under this  Lease.  Following  any sale by Lessor of the  property  of which the
Leased  Premises are a part, all  obligations to the assigning  Lessor to Lessee
shall cease and  terminate and Lessee shall look solely to the successor for the
performance of Lessor's duties hereunder.

              (d)  Notwithstanding  the  foregoing,  this  Lease  shall  not  be
terminated so long as Lessee is not in default of any provisions in this Lease.


                                      -77-
<PAGE>



              (e)  Lessor shall,  within fifteen (15) days after the date hereof
(or prior to the effective date of any encumbrance  mentioned in this Section 28
created after the date hereof)  obtain from the holder of any such  encumbrance,
an agreement whereby if such holder or any successor in interest shall come into
possession  of the  Leased  Premises,  or any part  thereof,  by  dispossession,
foreclosure or otherwise,  or shall become the owner of such  property,  or take
over the rights of Lessor to such  property,  said holder  shall not disturb the
possession, use or enjoyment of the Leased Premises by Lessee, its successors or
assigns,  nor  disaffirm  this  Lease  or  Lessee's  rights  or  estate  granted
hereunder,  so long as Lessee performs all of its obligations in accordance with
the terms of this Lease.

         29.  RIGHT TO CURE DEFAULTS
              ----------------------

              (a)  If  Lessee  shall  fail  to  comply  fully  with  any  of its
obligations  under this Lease,  then, in addition to Lessor's other rights,  but
not the  duty,  to cure  such  breach  at  Lessee's  expense.  Lessee  agrees to
reimburse  Lessor,  within fifteen (15) days after Lessor submits a statement of
the amount due, as  Additional  Rent,  for all expenses  incurred by Lessor as a
result of any efforts made by Lessor to cure any such breach.

              (b)  If  Lessor  shall  fail  to  comply  fully  with  any  of its
obligations  under this Lease,  then,  in addition to Lessee's  other rights and
remedies under this Lease at law and in equity, Lessee shall have the right, but
not the duty,  to cure such breach at Lessor's  expense;  provided that prior to
the  exercise of such right to cure,  Lessee  shall give Lessor  written  notice
specifying  the nature of the breach and Lessor  shall be  entitled  to ten (10)
days  after  receipt of such  notice  within  which to cure said  breach or such
additional  time as may be necessary if such breach is not  susceptible  to cure
within said ten (10) days,  in which case Lessor  shall  commence to cure within
said ten (10) day period. Lessor agrees to reimburse Lessee, within fifteen (15)
days after  Lessee  submits a  statement  of the amount  due,  for all  expenses
incurred by Lessee as a result of any efforts by Lessee to cure any such breach.
If Lessor fails to reimburse  Lessee as aforesaid,  Lessee may offset the amount
due against the payments of Rent  becoming  due  hereunder  unless  Lessor gives
written  notice of dispute  within said  fifteen  (15) day period  either to the
existence of any default or the  reasonableness  of the amount expended to cure.
In the event such notice of dispute is given, the provisions of subparagraph (c)
shall govern. The right to setoff against Rent shall be subordinate to and there
shall be no setoff  against the holder of any  mortgages or deed of trust or any
purchaser  at  foreclosure  or deed in lieu thereof on all or any portion of the
Leased  Premises.  The amount of all setoffs shall be limited to the  cumulative
sum of One Hundred Thousand Dollars ($100,000.00).

              (c)  If  Lessor  has  given  notice  of  dispute  as  provided  in
subparagraph (b), Lessee may have the issues of whether the Lessor is in default
of  its  obligations  or  the  reasonableness  of  the  amount  of  expenditures
determined by arbitration.  Pending the results of such arbitration, there shall
be no setoff. In the event the arbitrators determine that Lessor was in default,
Lessor  shall pay all costs of  arbitration  and Lessee  shall have the right to


                                      -78-
<PAGE>



offset  all of its costs and  expenses  of  remedying  such  default  (including
unreimbursed costs of the arbitration  proceeding)  against the payments of Rent
becoming due hereunder, subject to the limitations set forth in subparagraph (b)
above. If the arbitrators  determine that Lessor was not in default, then Lessee
will pay all of the arbitration.

              (d)  If Lessor is determined  to be in default in its  obligations
under  Paragraph  15(c) of this Lease and Lessee  shall  remedy such  default in
accordance with the preceding paragraph,  Lessee shall be entitled to offset one
hundred  fifteen  percent  (115%) of the costs and  expenses of  remedying  such
default, with the additional fifteen percent (15%) being to reimburse Lessee for
its overhead.

         30.  BROKERAGE
              ---------

              Lessor hereby acknowledges that Montgomery Realty, Inc. ("Broker")
has served as  Lessor's  agent in  connection  with this Lease and agrees to pay
said Broker a commission as per a separate  agreement between Lessor and Broker.
Lessor  warrants  to Lessee and Lessee  warrants to Lessor that it has not dealt
with any other  broker or real estate  agent or finder in  connection  with this
Lease and that, except for the aforesaid  commission payable to Broker, no right
or claim for  commission or other  compensation  has been created by its actions
with  respect to this Lease.  Lessor and Lessee  shall  indemnify  and hold each
other  harmless  against all loss,  liability or expense,  including  reasonable
attorney's fees and litigation costs, incurred by the other to the extent one or
the other is shown to be in breach of the foregoing warranties.

         31.  EFFECT OF CONVEYANCE
              --------------------

              If during the term of this Lease  Lessor sells its interest in the
Leased  Premises or this Lease,  then from and after the effective  date of such
sale,  Lessor  shall  be  released  and  discharged  from  any and  all  further
obligations and responsibilities  under this Lease except those already accrued.
Any such sale  shall be  subject to this  Lease and  Lessor  shall  require  any
purchaser to acknowledge the existence of Lessee's tenancy.

         32.  INTERPRETATION
              --------------

              The captions by which the  paragraphs of this Lease are identified
are for  convenience  only and shall have no effect upon the  interpretation  of
this Lease. Whenever the context so requires,  the singular number shall include
the plural,  and plural shall refer to the singular and the neuter  gender shall
include the masculine and feminine genders. If any provision of this Lease shall
be held to be unenforceable by a court, the remaining provisions shall remain in
effect and shall in no way be impaired.


                                      -79-
<PAGE>



         33.  ENTIRE INSTRUMENT
              -----------------

              All of the agreements previously and contemporaneously made by the
parties are  contained  in this Lease,  and this Lease cannot be modified in any
respect except by a writing executed by Lessor and Lessee.

         34.  ESTOPPEL CERTIFICATES
              ---------------------

              Recognizing  that both  parties may find it necessary to establish
to third parties, such as accountants,  banks,  mortgagees or the like, the then
current status of performance hereunder, either party, on the written request of
one to the  other  made  from  time to time,  will  promptly  furnish  a written
certificate  on the status of any matter  pertaining  to this Lease in such form
and substances as may from time to time be reasonably required.

         35.  NOTICES
              -------

              Any notices and other  communications  required or permitted to be
given by either  party to the other  shall be in writing  and shall be deemed to
have been served when hand  delivered  or, if the United States Mail is used, on
the second business day after the notice is deposited in the United States Mail,
postage prepaid, registered or certified mail, or by overnight delivery service,
and addressed to the parties as follows:

         To Lessee:               Jacques R. Rubin
                                  President
                                  Bio Science Contract Product Corp.
                                  9000 Virginia Manor Road
                                  Suite 290
                                  Beltsville, Maryland  20705

         To Lessor:               Muirkirk Manor Associates Limited Partnership
                                  c/o The Anastasi Stephens Group, Inc.
                                  9000 Virginia Manor Road, Suite 201
                                  Beltsville, Maryland   20705

Either party,  by written  notice to the other,  may change its address to which
notices are to be sent.


                                      -80-
<PAGE>



         36.  WAIVER
              ------

              Any waiver of either  Lessor or Lessee of any  default,  breach or
failure by the other to comply with any term,  condition,  or  provision of this
Lease shall not constitute a waiver of any other  default,  breach or failure by
such  defaulting  party.  No covenant,  term or condition of this Lease shall be
deemed to have been waived by either  party unless such waiver be in writing and
signed by the party to be charged therewith.

         37.  QUIET ENJOYMENT
              ---------------

              So  long as  Lessee  is not in  default  beyond  applicable  grace
periods,  Lessee shall have peaceful and quiet use and  possession of the Leased
Premises  without  hindrance  on the part of Lessor or any person  claiming  by,
through or under Lessor.

         38.  RECORDING THIS LEASE
              --------------------

              Lessee may not record  either this Lease nor a memorandum  thereof
among or in any public records without Lessor's prior written consent.

         39.  GOVERNING LAW
              -------------

              All questions with respect to  construction  of this Lease and the
rights and liabilities of the parties shall be determined in accordance with the
laws of the State of Maryland.

         40.  BENEFIT
              -------

              Subject to the restrictions on assignment and subletting set forth
in Paragraph 20, the  covenants,  terms and conditions of this Lease shall inure
to the  benefit of and be binding  upon  Lessor and Lessee and their  respective
successors and assigns.

         41.  REASONABLE CONSENT
              ------------------

              Wherever in this Lease  Lessor or Lessee is required to obtain the
consent or  approval of the other,  it is agreed  that such  consent or approval
shall not be unreasonably withheld or delayed.

         42.  TIME OF ESSENCE
              ---------------

              Time is of the  essence  in the  performance  of all of Lessor and
Lessee's obligations under this Lease.

                  (See Lease Addendum for Paragraphs 43 and 44)


                                      -81-
<PAGE>



         IN WITNESS WHEREOF, the parties have executed this Lease on the day and
year first above written.


WITNESS:                           LESSOR:

                                   MUIRKIRK MANOR ASSOCIATES
                                   LIMITED PARTNERSHIP,
                                   a Maryland limited partnership

                                   By:   THE ANASTASI STEPHENS GROUP, INC.
                                         its general partner


/s/ Jolina Early                         By: /s/ Joseph Anastasi         (SEAL)
------------------                           ----------------------------------


WITNESS:                           LESSEE:

                                   BIO SCIENCE CONTRACT PRODUCTION CORP.
                                   a Maryland corporation


/s/ Jolina Early                         By:  /s/ Jacques R. Rubin
-------------------                          ----------------------



                                      -82-
<PAGE>



                              EXHIBIT "C" (PART II)

                                 LEASE ADDENDUM
                                 --------------


                                  (PARK PLACE)


         THIS LEASE ADDENDUM made as of the 20th of March,  1992, is attached to
and made part of that certain  Lease of even date  herewith (the "Lease") by and
between  MUIRKIRK  MANOR  ASSOCIATES  LIMITED  PARTNERSHIP,  a Maryland  limited
partnership ("Lessor"), and Bio Science Contract Production Corp., a Maryland
corporation ("Lessee").

                              W I T N E S S E T H:
                              - - - - - - - - - -

         WHEREAS,  Lessor and Lessee  have  agreed to amend,  supplement  and/or
modify  the  Lease as herein  provided,  Landlord  and  Tenant  hereby  agree as
follows:

         1.   TERM - OPTION
              -------------

              Lessee, at its option,  shall have the right to extend the Term of
this Lease on the same  terms and  conditions,  as the  original  term  thereof,
except as otherwise provided in this Addendum with respect to the amount of Base
Rent  due  during  the  respective  extension  period,  for two  (2)  additional
consecutive terms of Five (5) years each (the "Extension  Periods"),  subject to
the satisfaction of the following conditions:

              (i)  Lessee's option to extend the Lease for each of the Extension
Periods shall be  exercisable  only by written  notice to Lessor at least ninety
(90) days prior to the  commencement  date of each Extension  Period.  If Lessee
does not give Lessor written notice as aforesaid, Lessee shall be deemed to have
not exercised its respective extension option.

              (ii)   At  the  time  of   exercise  of  the  option  and  at  the
commencement of each Extension Period,  Lessee shall not be in default under the
Lease beyond any applicable grace period.

              (iii)  Upon exercising the  option,  the  Base  Rent  will  be the
product  obtained by  multiplying  the Base Rent for the  immediately  preceding
Lease Year by one hundred four percent (104%).


                                      -83-
<PAGE>



         2.   RENT
              ----

              For months 1 through 5 of the first base year,  the  monthly  base
rent is  hereby  abated.  Monthly  base  rent  payments,  in full,  shall  begin
September  1, 1992.  It is agreed  that  Common  Area  Maintenance  charges  and
Additional  Rent,  if any,  will be  collected  on the first  day of  occupancy,
pursuant to Paragraph 8.(c).

              LESSEE IMPROVEMENTS
              -------------------

              (a)  Lessor has agreed to construct and complete the  installation
of Lessee  improvements,  as set forth in  Exhibit  "B" to the  Lease,  within a
budget of one hundred and twenty  thousand and 00/100  ($120,000.00)  toward the
improvements requested by the Lessee and it is agreed that the demising wall and
 .60 per s.f.  for design is part of the above  allowance.  It is agreed that all
plans,  specifications,  the General Contractor and its sub contractors, as well
as their  work  schedule,  will be  approved  by the  lessor  or its  Architect.
Payments to the General  Contractor will be made in accordance with the schedule
and method established by the Lessor and its lender.

              (b)  In the event that the cost of constructing and installing the
Lessee improvements to the Leased Premises exceeds the $120,000.00, lessee shall
pay directly to the General  Contractor the difference  between the cost and the
allowance.


                                      -84-
<PAGE>



         IN WITNESS  WHEREOF,  the parties have executed this Lease  Addendum on
the day and year first above written.


ATTEST:                                      LESSOR:

                                             MUIRKIRK MANOR ASSOCIATES LIMITED
                                             PARTNERSHIP,
                                             A Maryland limited partnership

                                             By:   THE ANASTASI STEPHENS GROUP,
                                                   INC.,
                                                   its general partner



/s/ Jolina Early                             By:   /s/ Joseph Anastasi
----------------                                   -------------------



                                               LESSEE:

                                               BIO SCIENCE CONTRACT PRODUCTION
                                               CORP.,
                                               a MARYLAND corporation



/s/ Jolina Early                               By:   /s/ Jacques R. Rubin
-----------------                                    ---------------------


                                      -85-
<PAGE>


                                   EXHIBIT "D"

                               AMENDMENT TO LEASES
                              -------------------

         THIS AMENDMENT TO LEASES ("Amendment"),  dated as of 12 November, 1992,
is by and between  MUIRKIURK MANOR ASSOCIATES  LIMITED  PARTNERSHIP,  a Maryland
limited  partnership  ("Lessor"),  and  CEPHALON  PROPERTY  MANAGEMENT,  INC., a
Delaware corporation ("Lessee"), with reference to the following background:

         A. Pursuant to a certain Lease dated December 28, 1990 ("First Lease"),
a certain  Lease dated  November 12, 1991  ("Second  Lease") and a certain Lease
dated March 20, 1992 ("Third  Lease";  the First  Lease,  Second Lease and Third
Lease are collectively referred to herein as the "Leases"), Lessor leased to the
Bio Science Contract  Production Corp., a Maryland  corporation ("Bio Science"),
certain  premises  known as Suites 260, 270, 280 and 290,  9000  Virginia  Manor
Road,  Beltsville,  Prince  George's  County,  Maryland,  as  more  particularly
described in the Leases ("Premises").

         B. Bio Science has assigned all of its right, title and interest in and
to the Leases and the Premises to Lessee  pursuant to a certain  Assignment  and
Assumption of Leases dated November, 1992.

         C. Lessor and Lessee desire to modify  certain terms and  provisions of
the Leases as hereinafter set forth.

         NOW, THEREFORE,  for good and valuable  consideration,  the receipt and
sufficiency of which are hereby acknowledged,  and intending to be legally bound
and to bind their respective successors and assigns,  Lessor and Lessee agree as
follows:

         1.   USE.  (A)   Without limiting anything contained therein, Section 5
              of the Leases is hereby amended to expressly  permit Lessee to use
              the Premises for the research, development, testing and production
              of biological  compounds and other  pharmaceutical  substances for
              commercial and no-commercial purposes.

                    (B)   Lessee  shall  defend,  indemnify  and  save  harmless
              Lessor  from  and  against  any and  all  liabilities,  costs  and
              expenses  (including  reasonable  attorneys' fees) imposed upon or
              incurred  by Lessor  solely by  reason of any act or  omission  of
              Lessee in the use and storage of any Hazardous  Substance on or in
              the Premises or in the disposal of any such  Hazardous  Substance.
              As used herein,  "Hazardous  Substance"  shall mean any  hazardous
              substance,  toxic  material  or other  substance  regulated  under
              federal, state or local law.


                                      -86-
<PAGE>



         2. ASSIGNMENT.  Notwithstanding  anything to the contrary  contained in
Section 20 or  elsewhere  in the Leases,  and  subject to  Lessor's  mortgagee's
consent,  Lessee  shall,  provided  it is not then in  default  under the Leases
beyond any applicable  grace period,  have the right and privilege to assign one
or more of the Leases, without Landlord's consent, to an Affiliate of Lessee. As
used herein, "Affiliate" shall mean any person or entity controlling, controlled
by or under common control with Lessee.  Lessee shall give Lessor written notice
of any assignment made under this Section 2.

         3.  ACCESS.  Notwithstanding  anything  to the  contrary  contained  in
Section 27 or elsewhere  in the Leases,  Lessee shall have the right to prohibit
Lessor's   access  to  those  portions  of  the  Leased  Premises  that  contain
confidential or proprietary  information or involve a risk of  contamination  to
the compounds being produced therein.

         4. NOTICES.  Section 35 of the Leases is hereby amended to require that
all notices  required or  permitted to be given by Lessor under the Leases shall
be delivered to Lessee at the following address:  145 Brandywine  Parkway,  West
Chester, PA 19380, Attention: President.

         5. OPTION TO EXTEND FIRST LEASE.  Lessee, at its option, shall have the
right to extend the term of the First Lease on the same terms and  conditions as
the original term thereof, except as otherwise provided in Section 5(iii) hereof
with  respect to the amount of Base Rent due  during  the  respective  extension
period,  for two (2)  additional  consecutive  terms of five (5) years  (each an
"Extension Period), subject to the satisfaction of the following conditions:

              (i)  Lessee's  option to extend the First Lease for the  Extension
Periods shall be  exercisable  only by written  notice to Lessor at least ninety
(90) days prior to the commencement date of the Extension Period. If Lessee does
not give Lessor written notice as aforesaid,  Lessee shall be deemed to have not
exercised its respective extension option.

              (ii) At the time of exercise of the option and at the commencement
of the Extension Period,  Lessee shall not be in default under the Leases beyond
any applicable grace period.

              (iii)  Upon  exercising  the  option,  the Base Rent for the First
Lease  will be the  product  obtained  by  multiplying  the  Base  Rent  for the
immediately preceding Lease Year by one hundred four percent (104%).

         6.  LEASE  IMPROVEMENTS.  Subsections  (a) and (b) of Section 3 (Lessee
Improvements)  of the Lease  Addendum to the Third Lease are hereby  deleted and
the following shall be inserted in place thereof:


                                      -87-
<PAGE>



                   (a)  Lessor  has  agreed  to   construct   and  complete  the
              installation of Lessee  improvements,  as set forth in Exhibit "B"
              to the Lease,  within a budget of one hundred twenty  thousand and
              00/100 dollars ($120,000.00) towards the improvements requested by
              the Lessee  and it is agreed  that the  demising  wall and .60 per
              s.f. for design is part of the above allowance.  It is agreed that
              all  plans,   specifications,   the  General  Contractor  and  its
              subcontractors,  as well as their work schedule,  will be approved
              by Lessee or its Architect. Payment of the General Contractor will
              be made in accordance with the schedule and method  established by
              the Lessor and its lender.

                   (b) In the event that the cost of constructing and installing
              the  Lessee   improvements  to  the  Leased  Premises  exceed  the
              $120,000,  Lessee shall pay directly to the General Contractor the
              difference between the cost and the allowance.

         7.  DURATION.  The  amendments to the Leases  resulting  from Section 1
through 5 of this Amendment shall remain in effect for so long as Lessee remains
the assignee of Bio Science's interest in the Leases.

         8. NO  FURTHER  AMENDMENT.  Except as amended  by this  amendment,  all
terms, provisions and agreements contained in the Leases are hereby ratified and
confirmed and remain in full force and effect.











                        [this space intentionally blank]



                                      -88-
<PAGE>



         IN WITNESS  WHEREOF,  Lessor and Lessee  have each duly  executed  this
Amendment as of the date first above written.


                                        MUIRKIRK MANOR ASSOCIATES
                                        LIMITED PARTNERSHIP,
                                        a Maryland limited partnership



                               By:      THE ANASTASI STEPHENS GROUP, INC.
                                        a Maryland close corporation its General
                                        Partner
                                        its General Partner


                                        By: /s/ Joseph Anastasi
                                            --------------------
                                        Name:   Joseph Anastasi
                                        Title:


                                        By: /s/ R. Glenn Stephens
                                            ---------------------
                                        Name:   R. Glenn Stephens
                                        Title:


                               CEPHALON PROPERTY MANAGMENT, INC.
                               a Delaware corporation


                                        By: /s/ Bruce A. Peacock 
                                            ---------------------
                                        Name:
                                        Title:



                                      -89-
<PAGE>



                              EXHIBIT "D" (PART II)

                       ASSIGNMENT AND ASSUMPTION OF LEASES


         THIS ASSIGNMENT AND ASSUMPTION OF LEASES ("Assignment") is entered into
as of the 14th day of December , 1992, by BIO SCIENCE CONTRACT PRODUCTION CORP.,
a Maryland Corporation ("Assignor"),  and C EPHALON PROPERTY MANAGEMENT, INC., a
Delaware  corporation  ("Assignee").  For  valuable  consideration,  the parties
hereto,  each  intending  to be  legally  bound  and to  bind  their  respective
successors and assigns, hereby convenant and agree as follows:

         1.  ASSIGNMENT.  Assignor hereby assigns,  transfers and sets over unto
Assignee,  and Assignee  hereby  accepts,  all of  Assignor's  right,  title and
interest in and to (i) that certain  Lease dated  December  28, 1990,  (ii) that
certain  Lease  dated  November  12,  1991 and  Addendum  thereto and (iii) that
certain  Lease dated March 20, 1992 and  Addendum  thereto,  copies of which are
attached  hereto as,  respectively,  Exhibits  "A" - "C" and made a part  hereof
(collectively,   "Leases"),  each  between  Muirkirk  Manor  Associates  Limited
Partnership,  a Maryland  limited  partnership,  as landlord,  and Assignor,  as
tenant,  which Leases  pertain to Suites 260, 270, 280 and 290,  90000  Virginia
Manor  Road,  Park  Place,   Beltsville,   Prince  George's   County,   Maryland
("Premises").  This Assignment  includes all security  deposits paid by Assignor
under  the  Leases  and  all  allowances   and  amounts   available  for  lessee
improvements to the Premises.


         2. REPRESENTATIONS AND WARRANTIES.  Assignor represents and warrants to
Assignee that: (a) Assignor is the tenant under the Leases and the sole occupant
of the Premises,  (b) the Leases are the only leases or  agreements  whereby any
person  has been  granted  the right to use or occupy the  Premises  or any part
thereof,  (c)  Assignor  has not  previously  assigned  the Leases or sublet the
Premises  and has  received no notice of a prior  assignment,  hypothecation  or
pledge of the Leases or the rent payable thereunder, (d) there exists no default
by Assignor or the  landlord  under the  Leases,  or, to the best of  Assignor's
knowledge,  no event,  fact or circumstance  which, with the giving of notice or
the passage of time,  or both,  would  constitute  a default,  (e) the  security
deposits due under the Leases have been paid in full, the amount of the security
deposits has not been reduced and Assignor's  interest in the security  deposits
has not been previously pledged,  transferred or assigned, (f) the copies of the
Leases which are attached  hereto are true,  correct and complete and constitute
the entire  agreement  between  Assignor and the landlord under the Leases,  (g)
there are no actions or proceedings,  whether voluntary or involuntary,  pending
with respect to Assignor under any  bankruptcy,  insolvency,  debt adjustment or
similar law of the United States or any state  thereof,  (h) the landlord  under
the Leases has fulfilled all of its  representation,  warranties  and agreements


                                      -90-
<PAGE>



under the  Leases,  and (i) the  construction  and  installation  of all "lessee
improvements"  to the Premises have been completed in all respects in accordance
with the Leases,  except for any items specified on Schedule I hereto, there are
no payments due the landlord  under the Leases or any other party from  Assignor
or due Assignor from the landlord  under the Leases in connection  with any such
work,  except as specified on Schedule II hereto,  and the amount of $211,413.49
remains available for use in completing such work.

         3.  PERFORMANCE.  Assignor shall be responsible  for the observance and
performance of all  agreements and  obligations of the "Lessee" under the Leases
arising prior to the Effective Date (defined below). Assignee, and not Assignor,
shall be responsible  for the  observance and  performance of all agreements and
obligations  of the "Lessee"  under the Leases arising on or after the Effective
Date.

         4. EFFECTIVE DATE.  Notwithstanding  anything to the contrary contained
herein,  this Assignment  shall not become effective until such date ("Effective
Date"),  if ever,  that  Assignor and Assignee (i) enter into an Asset  Purchase
Agreement  providing for  Assignee's  acquisition  of certain assets of Assignor
located  on the  Premises  and (ii)  consummate  the  transactions  contemplated
thereunder.

         5. CONTINUING OBLIGATIONS.  Assignor acknowledges,  pursuant to Section
20 of the  Leases,  that the  assignment  effected  hereby  shall  not  release,
discharge  or affect  the  liabilities  of  Assignor  under the  Leases and that
Assignor shall at all times remain primarily liable under the Leases.

         6.  TERMINATION.  Assignee  shall have the absolute  and  unconditional
right and  privilege to terminate  this  Assignment as to any Lease at any time,
upon five (5) days' prior written  notice to Assignor.  As of the date specified
in any such  notice  ("Termination  Date"),  Assignor  shall be fully and solely
liable for all agreements  and  obligations of the "Lessee" under such Lease and
Assignee  shall have no further  obligations  under such  Lease,  except for any
liability or obligation  accrued  between the Effective Date and the Termination
Date.

         7.  INDEMNITY.  Assignor  shall  defend,  protect,  indemnify  and save
harmless  Assignee  from and against any and all  liabilities,  suits,  actions,
losses, damages, costs and expenses, including, without limitation, counsel fees
and court costs,  suffered or incurred by Assignee resulting from or relating to
any  failure  by  Assignor  to  observe  or  perform  any of its  agreements  or
obligations  under  the  Leases  prior  to  the  Effective  Date  or  after  the
Termination Date.


                                      -91-
<PAGE>




         IN WITNESS WHEREOF, Assignor and Assignee have executed this Assignment
as of the date first above written.

(Corporate Seal)                                     BIO SCIENCE CONTRACT
Attest:                                                PRODUCTION CORP.

/s/ Cindi R. Caplan                                  By: /s/ Jacques R. Rubin
-------------------                                      ---------------------
Name:                                                     Name:
Title:                                                    Title:

(Corporate Seal)                                     CEPHALON PROPERTY
Attest:                                                 MANAGEMENT, INC.

/s/ Bruce A. Peacock                                 By: /s/ Frank Baldino
--------------------                                     -----------------
Name:                                                    Name:
Title:                                                   Title:


                                      -92-
<PAGE>



                                   SCHEDULE I

                         UNCOMPLETED LESSEE IMPROVEMENTS
                         -------------------------------

                                      NONE.



































                                      -93-
<PAGE>




                                   SCHEDULE II

                       AMOUNT DUE FOR LESSEE IMPROVEMENTS
                       ----------------------------------

                                      NONE.



































                                      -94-
<PAGE>



                                   EXHIBIT "E"

                                LETTER AGREEMENT
                                ----------------



                                                        December 29, 1992


Muirkirk Manor Associates
  Limited Partnership
9000 Virginia Manor Road, Suite 210
Beltsville, MD 20705

Bio Science Contract Production Corp.
10000 Virginia Manor Road, Suite 340
Beltsville, MD 20705

                  Re:      9000 Virginia Manor Road, Beltsville
                           Maryland (Suites 260, 270, 280 and 290)
                           (the "Premises")
                           ----------------------------------------

Gentlemen:

         As you  know,  Bio  Science  desires  to assign  to  Cephalon  Property
Management,  Inc. ("CPMI") three leases for the Premises between Bio Science, as
Tenant, and Muirkirk Manor Associates Limited Partnership, as Landlord, pursuant
to an  Assignment  and  Assumption  of  Leases  dated  December  14,  1992  (the
"Assignment  Agreement").  The Landlord is required to obtain the consent of the
party holding the mortgage on the Premises,  Potomac  Equity  Portfolio  Limited
Partnership,  an Illinois  limited  partnership  ("Lender"),  to the  Assignment
Agreement,  as well as to the Amendment to Leases  between the Landlord and CPMI
dated  November 12, 1992,  which is to become  effective as of December 14, 1992
(the "Amendment").

         As a condition to giving its  consent,  the Lender has  requested  that
certain changes be made to the Assignment  Agreement and the Amendment,  and Bio
Science,  Muirkirk and CPMI wish to amend the documents to make such changes, as
follows:

         1. The first  sentence  of  Section 6 of the  Assignment  Agreement  is
hereby amended and restated in its entirety as follows:

         "Assignee  shall  have  the  right  and  privilege  to  terminate  this
         Assignment at any time,  upon 180 days prior written notice to Assignor
         and to Assignor's lender,  Potomac Equity Portfolio Limited Partnership
         (if it  continues  to hold the mortgage  covering  the  Premises)  (the


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<PAGE>



         "Lender"),  PROVIDED  that  such  termination  is in  conjunction  with
         Assignee's  transfer to Assignor of substantially  all of the equipment
         of  Assignor  acquired  by  Assignee  as of  December  14, 1992 (or the
         functional  equivalent  thereof) in substantially the same condition as
         existed as of November 11, 1992 or, in CPMI's discretion,  cash in lieu
         thereof at the value agreed to by CPMI and Assignor."

         2.  A new Section 8 is hereby added to the Assignment Agreement,  which
states in its entirety as follows:

         "8.  NOTICES.  All notices to be delivered  hereunder  shall be sent by
         hand delivery,  facsimile (with a confirmation copy sent by first-class
         mail) or reputable overnight courier, to the following addresses:

                  If to Assignor, to:

                  Bio Science Contract Production Corp.
                  10000 Virginia Manor Road, Suite 340
                  Beltsville, MD 20705

                  If to Lender, to:

                  Potomac Equity Portfolio Limited Partnership
                  c/o Amresco Institutional, Inc.
                  8300 Greensboro Drive, Suite 700
                  McLean, VA 22102
                  Attention:  David Cundiff

                  or to such other  address or  addressee  as shall be  properly
                  furnished to the other parties in the manner specified in this
                  paragraph 8."

                  3. Section 1(B) of the  Amendment is hereby  amended to insert
the phrase  "and its  successors  and  assigns"  after the word  "Lessor" in the
second line and in the fourth line.

                  4. Any  assignment  of the Leases to an Affiliate  pursuant to
Section 2 of the Amendment shall require the consent of Potomac Equity Portfolio
Limited Partnership, as the holder of the mortgage covering the Premises.

                  5. Section 3 of the  Amendment is hereby  amended and restated
in its entirety to read as follows:

                  "Notwithstanding anything to the contrary contained in Section
                  27 or elsewhere in the Leases,  Lessee shall have the right to
                  prohibit  Lessor's  access  to those  portions  of the  Leased


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<PAGE>



                  Premises that contain confidential or proprietary  information
                  or  involve a risk of  contamination  to the  compounds  being
                  produced therein, unless Lessor has, as appropriate,  signed a
                  mutually  satisfactory  form of  confidentiality  agreement or
                  taken such precautions as may be reasonably prescribed by CPMI
                  to avoid such contamination."

                  6. CPMI's  obligations  in this letter shall become  effective
upon receipt of the executed  consent of the Lender to the Assignment  Agreement
and Amendment, in form and substance satisfactory to CPMI.

                  If the foregoing is correct, please indicate your agreement in
the space provided below.

                                                 Very truly yours,


                                                  CEPHALON PROPERTY
                                                    MANAGEMENT, INC.


                                                     By:/s/ Bruce A. Peacock
                                                        ---------------------



Acknowledged and agreed to by:

MUIRKIRK MANOR ASSOCIATES
  LIMITED PARTNERSHIP
By The Anastasi Stephens Group, Inc.,
      its General Partner

By:/s/ Joseph Anastasi
   -------------------

BIO SCIENCE CONTRACT PRODUCTION CORP.


By:/s/ Jacques R. Rubin
   ---------------------
      Jacques R. Rubin
      President



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