<PAGE>
                                       1



                                 Promissory Note


Date August 20, 1998
Amount $25,000.00                            Maturity Date February 20, 1999


===============================================================================
Lender:                                       Borrowers:

Stanley D. Estrin Irrevocable Trust           Medical Technology Systems, Inc.
dtd 3/16/93, Judith C. Estrin, Trustee        12920 Automobile Boulevard
6720 N. W. 105th Lane                         Clearwater, Florida 33762
Parkland, Florida  33076

===============================================================================


     FOR VALUE RECEIVED,  the undersigned Borrower  unconditionally (and jointly
and  severally,  if more than one)  promises to pay to the order of Lender,  its
successors  and  assigns,  without  setoff,  at  its  offices  indicated  at the
beginning of this Note,  or at such other place as may be  designated by Lender,
the principal amount of Twenty Five Thousand and No/100 Dollars ($25,000.00), or
so much thereof as may be advanced  from time to time in  immediately  available
funds,  together  with  interest  computed  daily on the  outstanding  principal
balance  hereunder,  at an annual  interest  rate,  and in  accordance  with the
payment schedule, indicated below.

     1. Rate.

     Fixed Rate. The Rate shall be fixed at twelve percent (12.0%) per annum.

     Notwithstanding  any  provision  of this  Note,  Lender  does not intend to
charge and Borrower shall not be required to pay any amount of interest or other
charges in excess of the maximum permitted by the applicable law of the State of
Florida;  if any higher rate  ceiling is lawful,  then that higher rate  ceiling
shall apply. Any payment in excess of such maximum shall be refunded to Borrower
or credited against principal, at the option of Lender.

     2. Accrual Method.  Unless  otherwise  indicated,  interest at the Rate set
forth above will be  calculated  by the  365/360  day method (a daily  amount of
interest  is  computed  for a  hypothetical  year of 360  days;  that  amount is
multiplied by the actual  number of days for which any principal is  outstanding
hereunder).

     3. Payment Schedule. All payments received hereunder shall be applied first
to the payment of any expense or charges  payable  hereunder  or under any other
loan documents  executed in connection  with this Note, then to interest due and
payable, with the balance applied to principal, or in such other order as Lender
shall determine at its option.

     Single  Payment.  Principal and interest  shall be paid in full in a single
payment  on  February  20,  1999.The   maturity  date  of  this  Note  shall  be
automatically  extended from February 20, 1999, to May 20, 1999, if the Borrower
satisfies  all of the  terms and  conditions  of a Loan  Agreement  of even date
herewith between Borrower and Lender.

     4. Waivers,  Consents and  Covenants.  Borrower,  any endorser or guarantor
hereof,  or any other party hereto  (individually  an "Obligor" and collectively
"Obligors")  and each of them  jointly  and  severally:  (a) waive  presentment,
demand,  protest,  notice of demand,  notice of intent to accelerate,  notice of
acceleration  of maturity,  notice of protest,  notice of nonpayment,  notice of
dishonor, and any other notice required to be given under the law to any Obligor
in connection with the delivery, acceptance, performance, default or enforcement
of this Note, any  endorsement or guaranty of this Note, or any other  documents
executed in connection  with this Note or any other note or other loan documents
now or  hereafter  executed in  connection  with any  obligation  of Borrower to
Lender (the "Loan Documents");  (b) consent to all delays, extensions,  renewals
or other  modifications  of this Note or the Loan  Documents,  or waivers of any
term hereof or of the Loan  Documents,  or release or discharge by Lender of any
of  Obligors,  or release,  substitution  or exchange  of any  security  for the
payment hereof,  or the failure to act on the part of Lender,  or any indulgence
shown by Lender (without notice to or further assent from any of Obligors),  and
agree that no such  action,  failure to act or failure to exercise  any right or
remedy  by Lender  shall in any way  affect or  impair  the  obligations  of any
Obligors or be construed as a waiver by Lender of, or otherwise  affect,  any of
Lender's rights under this Note,  under any endorsement or guaranty of this Note
or under any of the Loan Documents;  and (c) agree to pay, on demand,  all costs
and  expenses of  collection  or defense of this Note or of any  endorsement  or
guaranty  hereof  and/or the  enforcement  or defense of  Lender's  rights  with
respect to, or the administration,  supervision, preservation, or protection of,
or realization  upon, any property securing payment hereof,  including,  without
limitation,  reasonable  attorney's and paralegal=s fees, including fees related
to  any  suit,  mediation  or  arbitration  proceeding,  out  of  court  payment
agreement,  trial, appeal,  bankruptcy proceedings or other proceeding,  in such
amount as may be determined reasonable by any arbitrator or court,  whichever is
applicable.


<PAGE>



5.  Indemnification.  Obligors agree to promptly pay,  indemnify and hold Lender
harmless from all State and Federal taxes of any kind and other liabilities with
respect to or resulting from the execution  and/or  delivery of this Note or any
advances made pursuant to this Note. If this Note has a revolving feature and is
secured  by a  mortgage,  Obligors  expressly  consent to the  deduction  of any
applicable taxes from each taxable advance extended by Lender.

6. Prepayments.  Prepayments may be made in whole or in part at any time without
premium or penalty. All prepayments of principal shall be applied in the inverse
order of maturity,  or in such other order as Lender shall determine in its sole
discretion.

7. Delinquency  Charge. To the extent permitted by law, a delinquency charge may
be imposed in an amount not to exceed four  percent  (4%) of any payment that is
more than fifteen days late.

8. Events of Default.  The  following  are events of default  hereunder: (a) the
failure to pay any  obligation,  liability  or  indebtedness  of any  Obligor to
Lender, whether under this Note or any Loan Documents,  as and when due (whether
at  maturity  or  by  acceleration);  (b)  the  failure  to  perform  any  other
obligation, liability or indebtedness of any Obligor to Lender, which failure is
not  cured  within  fifteen  (15) days  from the date on which  Lender  provides
Borrower  written notice of such failure to the extent that any such default can
be cured by Borrower;  (c) the commencement of a proceeding  against any Obligor
for  dissolution or  liquidation,  the voluntary or  involuntary  termination or
dissolution of any Obligor or the merger or consolidation of any Obligor with or
into  another  entity;  (d) the  insolvency  of, the  business  failure  of, the
appointment  of a custodian,  trustee,  liquidator or receiver for or for any of
the property of, the  assignment  for the benefit of creditors by, or the filing
of a petition under bankruptcy,  insolvency or debtor's relief law or the filing
of a petition for any adjustment of indebtedness, composition or extension by or
against any Obligor;  (e) the determination by Lender that any representation or
warranty made to Lender by any Obligor in any Loan  Documents or otherwise or in
any  financial  statement  or financial  information  submitted to Lender by any
Borrower is or was, when it was made, untrue or materially  misleading;  (f) the
entry of a judgment against any Obligor in excess of $50,000.00,  which judgment
is not satisfied or bonded off within thirty (30) days from the date of entry of
the judgment;  (g) the seizure or forfeiture  of, or the issuance of any writ of
possession, garnishment or attachment which writ relates to any damage in excess
of $50,000.00  and which writ is not dismissed  within thirty (30) days from the
date of issuance of any such writ; or (h) the failure of any Borrower's business
to comply in any material  respect with any law or  regulation  controlling  its
operation.

<PAGE>
                                       2

     9. Remedies upon Default.  Whenever  there is a default under this Note (a)
the  entire  balance  outstanding  hereunder  and all other  obligations  of any
Obligor  to Lender  (however  acquired  or  evidenced)  shall,  at the option of
Lender,  become  immediately  due and  payable and any  obligation  of Lender to
permit further  borrowing under this Note shall immediately cease and terminate,
and/or (b) to the extent  permitted  by law,  the Rate of interest on the unpaid
principal  shall be  increased  at Lender's  discretion  up to the maximum  rate
allowed by law, or if none, 18% per annum (the "Default  Rate"). The  provisions
herein for a Default Rate shall not be deemed to extend the time for any payment
hereunder or to constitute a "grace period" giving  Obligors a right to cure any
default.  At Lender's option,  any accrued and unpaid interest,  fees or charges
may, for purposes of computing and accruing  interest on a daily basis after the
due date of the Note or any installment  thereof,  be deemed to be a part of the
principal  balance,  and interest shall accrue on a daily compounded basis after
such date at the Default Rate provided in this Note until the entire outstanding
balance of  principal  and interest is paid in full.  Upon a default  under this
Note,  Lender is hereby authorized at any time, at its option and without notice
or demand, to set off and charge against any deposit accounts of any Obligor (as
well as any money, instruments,  securities,  documents, chattel paper, credits,
claims,  demands,  income and any other  property,  rights and  interests of any
Obligor),  which at any time shall come into the  possession or custody or under
the control of Lender or any of its agents,  affiliates or  correspondents,  any
and all  obligations due hereunder.  Additionally,  Lender shall have all rights
and remedies  available under each of the Loan Documents,  as well as all rights
and remedies  available at law or in equity.  Any judgment rendered on this Note
shall bear  interest  at the  highest  rate of  interest  permitted  pursuant to
Chapter 687, Florida Statutes.

     10.  Non-waiver.  The failure at any time of Lender to exercise  any of its
options or any other rights hereunder shall not constitute a waiver thereof, nor
shall it be a bar to the  exercise  of any of its  options  or rights at a later
date.  All rights and remedies of Lender shall be cumulative  and may be pursued
singly,  successively  or together,  at the option of Lender.  The acceptance by
Lender of any partial payment shall not constitute a waiver of any default or of
any of  Lender's  rights  under  this  Note.  No  waiver  of  any of its  rights
hereunder,  and no modification or amendment of this Note, shall be deemed to be
made by Lender  unless the same shall be in  writing,  duly  signed on behalf of
Lender;  each such waiver shall apply only with respect to the specific instance
involved,  and shall in no way impair the rights of Lender or the obligations of
Obligors to Lender in any other respect at any other time.

11.  Applicable  Law,  Venue  and  Jurisdiction.  This Note and the  rights  and
obligations  of Borrower  and Lender  shall be governed  by and  interpreted  in
accordance with the law of the State of Florida. In any litigation in connection
with or to enforce this Note or any  endorsement or guaranty of this Note or any
Loan Documents,  Obligors,  and each of them,  irrevocably consent to and confer
personal jurisdiction on the courts of the State of Florida or the United States
located  within the State of Florida and  expressly  waive any  objections as to
venue in any such courts.  Nothing  contained  herein  shall,  however,  prevent
Lender from bringing any action or exercising  any rights within any other state
or  jurisdiction  or from  obtaining  personal  jurisdiction  by any other means
available  under  applicable  law.  The  interest  rate  charged on this Note is
authorized  by  Chapter  655,  Florida  Statutes  and  Section  687.12,  Florida
Statutes.

     12. Partial Invalidity. The unenforceability or invalidity of any provision
of this Note  shall not  affect  the  enforceability  or  validity  of any other
provision herein and the invalidity or unenforceability of any provision of this
Note or of the Loan Documents to any person or circumstance shall not affect the
enforceability or validity of such provision as it may apply to other persons or
circumstances.

     13.  Binding  Effect.  This  Note  shall be  binding  upon and inure to the
benefit  of  Borrower,  Obligors  and Lender  and their  respective  successors,
assigns,  heirs  and  personal  representatives,   provided,  however,  that  no
obligations  of Borrower or Obligors  hereunder  can be assigned  without  prior
written consent of Lender.

     14. Controlling Document. To the extent that this Note conflicts with or is
in any way incompatible with any other document related specifically to the loan
evidenced by this Note,  this Note shall  control over any other such  document,
and if this Note does not address an issue,  then each other such document shall
control to the extent that it deals most specifically with an issue.

     15.  WAIVER  OF  JURY  TRIAL. AFTER CONSULTING  WITH  COUNSEL  AND  CAREFUL
CONSIDERATION,  BORROWER  AND  LENDER  (BY  ITS  ACCEPTANCE  HEREOF)  KNOWINGLY,
VOLUNTARILY,  AND INTENTIONALLY  WAIVE THE RIGHT ANY OF THEM MAY HAVE TO A TRIAL
BY JURY WITH  RESPECT  TO ANY  LITIGATION  ARISING  OUT OF THIS NOTE OR THE LOAN
DOCUMENTS, OR OUT OF ANY COURSE OF CONDUCT, COURSE OF DEALING,  STATEMENTS (ORAL
OR  WRITTEN),  OR  ACTIONS  OF  BORROWER  OR  LENDER. THIS WAIVER IS A  MATERIAL
INDUCEMENT TO LENDER'S  ACCEPTANCE OF THIS NOTE.  Borrower  represents to Lender
that the proceeds of this loan are to be used  primarily for business.  Borrower
acknowledges  having read and  understood,  and agrees to be bound by, all terms
and  conditions of this Note and hereby  executes this Note under seal as of the
date here above written.

NOTICE OF FINAL  AGREEMENT. THIS WRITTEN  PROMISSORY  NOTE  REPRESENTS THE FINAL
AGREEMENT  BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,
CONTEMPORANEOUS,  OR  SUBSEQUENT  ORAL  AGREEMENTS OF THE  PARTIES. THERE ARE NO
UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.


If this Note is secured by a mortgage on real property,  documentary stamp taxes
have been paid and affixed to the mortgage.

EXECUTION DATE:  August 20, 1998

                                        BORROWER:


                                        MEDICAL TECHNOLOGY SYSTEMS, INC.


                                        By:______________________________
                                           ______________________, as its
                                           ______________________________