<PAGE>   1
                                                                   EXHIBIT 10.85

                                 LOAN AGREEMENT


         LOAN AGREEMENT dated June 25, 1997 (the "Loan Agreement" or this
"Agreement") by and among PHARMACEUTICAL PRODUCT DEVELOPMENT, INC., a North
Carolina corporation (the "Borrower"), the subsidiaries and affiliates
identified on the signature pages hereto or hereafter joined as a Guarantor
hereunder (the "Guarantors", and together with the Borrower, the "Credit
Parties") and FIRST UNION NATIONAL BANK OF NORTH CAROLINA (the "Bank").

                               W I T N E S S E T H

         WHEREAS, the Borrower has requested a $50 million revolving credit
facility for the purposes hereinafter set forth;

         WHEREAS, the Bank has agreed to make the requested credit facility
available to the Borrower on the terms and conditions hereinafter set forth;

         NOW, THEREFORE, IN CONSIDERATION of the premises and other good and
valuable consideration, the receipt and sufficiency of which is hereby
acknowledged, the parties hereto agree as follows:

         SECTION 1.  DEFINITIONS.

         "Bankruptcy Code" means the Bankruptcy Code in Title 11 of the United
States Code, as amended, modified, succeeded or replaced from time to time.

         "Business Day" means a day other than a Saturday, Sunday or other day
on which commercial banks in Charlotte, North Carolina are authorized or
required by law to close; provided, however, that when used in connection with a
rate determination, borrowing or payment in respect of a LIBOR Rate Loan, the
term "Business Day" shall also exclude any day on which banks in London, England
are not open for dealings in U.S. dollar deposits in the London interbank
market.

         "Closing Date" means the date hereof.

         "Commitment Period" means the period from and including the date hereof
to but excluding the earlier of (i) the Termination Date, or (ii) the date on
which the commitments hereunder shall have been terminated in accordance with
the provisions hereof.

         "Consolidated Debt to Total Capitalization Ratio" means, as of any day,
the ratio of Consolidated Funded Debt to Consolidated Total Capitalization.

         "Consolidated Fixed Charge Coverage Ratio" means, as of the last day of
any fiscal quarter for the Borrower and its subsidiaries on a consolidated
basis, the ratio of Consolidated Income Available for Fixed Charges to
Consolidated Fixed Charges.

         "Consolidated Fixed Charges" means, for the applicable period for the
Borrower and its subsidiaries on a consolidated basis, the sum of Consolidated
Interest Expense plus rental and lease expense, in each case as determined in
accordance with GAAP applied on a consistent basis. Except as expressly provided
otherwise, the applicable period shall be for the four consecutive fiscal
quarters ending as of the date of determination.

         "Consolidated Funded Debt" means Funded Debt of the Borrowers and its
subsidiaries on a consolidated basis determined in accordance with GAAP.

         "Consolidated Income Available for Fixed Charges" means, for any period
for the Borrower and its subsidiaries on a consolidated basis, the sum of
Consolidated Net Income plus Consolidated


<PAGE>   2

Interest Expense plus federal, state and local income taxes paid plus rental and
lease expense, in each case determined in accordance with GAAP applied on a
consistent basis. Except as expressly provided otherwise, the applicable period
shall be for the four consecutive fiscal quarters ending as of the date of
determination.

         "Consolidated Interest Expense" means, for any period for the Borrower
and its subsidiaries on a consolidated basis, all interest expense, including
the amortization of debt discount and premium, the interest component under
capital leases and the implied interest component under securitization
transactions, expense, in each case determined in accordance with GAAP applied
on a consistent basis. Except as expressly provided otherwise, the applicable
period shall be for the four consecutive fiscal quarters ending as of the date
of determination.

         "Consolidated Net Income" means, for any period for the Borrower and
its subsidiaries on a consolidated basis, net income as determined in accordance
with GAAP applied on a consistent basis, but excluding for purposes of
determining the Fixed Charge Coverage Ratio, (i) extraordinary gains or losses,
and any taxes on such excluded gains and any tax deductions or credits on
account of any such excluded losses, and (ii) one-time non-recurring charges
associated with mergers and acquisitions permitted hereunder. Except as
expressly provided otherwise, the applicable period shall be for the four
consecutive fiscal quarters ending as of the date of determination.

         "Consolidated Net Worth" means, on any day for the Borrower and its
subsidiaries on a on a consolidated basis, shareholders' equity as determined in
accordance with GAAP applied on a consistent basis.

         "Consolidated Tangible Net Worth" means, on any day Consolidated Net
Worth minus the aggregate amount of goodwill, franchises, licenses, patents,
trademarks, trade names, copyrights, service marks, brand names, organizational
and developmental expenses, covenants not to compete and other intangible
assets, in each case as determined in accordance with GAAP applied on a
consistent basis.

         "Consolidated Total Capitalization" means, on any day for the Borrower
and its subsidiaries on a consolidated basis, the sum of Consolidated Funded
Debt plus Consolidated Net Worth.

         "Credit Documents" means, collectively, this Agreement and the Note.

         "Eurodollar Reserve Percentage" means for any day, the percentage
(expressed as a decimal and rounded upwards, if necessary, to the next higher
1/100th of 1%) which is in effect for such day as prescribed by the Federal
Reserve Board (or any successor) for determining the maximum reserve requirement
(including without limitation any basic, supplemental or emergency reserves) in
respect of Eurocurrency liabilities, as defined in Regulation D of such Board as
in effect from time to time, or any similar category of liabilities for a member
bank of the Federal Reserve System in New York City.

         "Funded Debt" means, as of any day for the Borrower, without
duplication, (i) all indebtedness for borrowed money, (ii) all indebtedness and
obligations evidenced by bonds, debentures, notes or other similar instruments,
(iii) all obligations to pay the deferred purchase price of property or services
(other than trade accounts payable arising in the ordinary course of business),
(iv) all obligations as lessee under capital leases, (v) all obligations of
reimbursement relating to letters of credit, bankers' acceptances or other
similar instruments (whether or not then drawn and owing), (vi) all Guaranty
Obligations, (vii) the attributed principal amount of any securitization
transaction and (viii) all obligations under any synthetic lease, tax retention
operating lease, off-balance sheet loan or other similar off-balance sheet
financing product where the product is considered borrowed money indebtedness
for tax purposes, but is classified as an operating lease for purposes of GAAP.

         "GAAP" means generally accepted accounting principles in the United
States applied on a consistent basis.


                                       2
<PAGE>   3

         "Governmental Authority" means any federal, state, local or foreign
court or governmental agency, authority, instrumentality or regulatory body.

         "Guaranteed Obligations" means:

                  (a) All unpaid principal of and interest on (including,
          without limitation, interest accruing at the then applicable rate
          provided in this Agreement after the maturity of the Loans and other
          obligations owing under this Agreement and interest accruing at the
          then applicable rate provided in this Agreement after the filing of
          any petition in bankruptcy, or the commencement of any insolvency,
          reorganization or like proceeding, relating to the Borrower, whether
          or not a claim for post-filing or post-petition interest is allowed in
          such proceeding) the Loans and all other obligations and liabilities
          of the Borrower to the Bank, whether direct or indirect, absolute or
          contingent, due or to become due, or now existing or hereafter
          incurred, which may arise under, out of, or in connection with, this
          Agreement, the Note or any other document relating hereto, in each
          case whether on account of principal, interest, reimbursement
          obligations, fees, indemnities, costs, expenses or otherwise
          (including, without limitation, all fees and disbursements of counsel
          to the Bank that are required to be paid by the Borrower pursuant to
          the terms of this Agreement); and

                  (b) all other indebtedness, liabilities and obligations of any
          kind or nature, now existing or hereafter arising, owing by the
          Borrower to the Bank, arising under any interest rate protection
          agreement, currency agreement or other agreement or arrangement,
          whether primary, secondary, direct, contingent, or joint and several.

         "Guaranty Obligation" means any obligation, contingent or otherwise,
directly or indirectly guaranteeing the indebtedness or other obligation of
another Person, including without limitation, (i) an agreement to purchase or
pay (or to supply or advance funds for the purchase or payment of) any such
indebtedness or other obligation (whether by way of partnership agreement,
keep-well agreement, comfort letter, maintenance agreement or the like), or (ii)
any arrangement entered into for the purpose of assuring payment of the
indebtedness or other obligation of another Person or otherwise protecting a
party from loss in respect thereof; provided that such term shall not include
endorsements for collection or deposit in the ordinary course of business.

         "Interest Payment Date" means (a) as to any Prime Loan, the last
Business Day of each March, June, September and December to occur while such
Loan is outstanding, (b) as to any LIBOR Rate Loan having an Interest Period of
three months or less, the last day of such Interest Period and (c) as to any
LIBOR Rate Loan having an Interest Period longer than three months, each day
which is three months after the first day of such Interest Period and the last
day of such Interest Period.

         "Interest Period" means with respect to any LIBOR Rate Loan,

                  (i) initially, the period commencing on the date of borrowing
         or conversion date, as the case may be, with respect to such LIBOR Rate
         Loan and ending one, two or three months thereafter, as selected by the
         Borrower in the notice of borrowing or notice of conversion given with
         respect thereto; and

                  (ii) thereafter, each period commencing on the last day of the
         immediately preceding Interest Period applicable to such LIBOR Rate
         Loan and ending one, two or three months thereafter, as selected by the
         Borrower by irrevocable notice to the Bank not less than three Business
         Days prior to the last day of the then current Interest Period with
         respect thereto;

                  provided that the foregoing provisions are subject to the
         following:



                                       3
<PAGE>   4

                           (A) if any Interest Period pertaining to a LIBOR Rate
         Loan would otherwise end on a day that is not a Business Day, such
         Interest Period shall be extended to the next succeeding Business Day
         unless the result of such extension would be to carry such Interest
         Period into another calendar month in which event such Interest Period
         shall end on the immediately preceding Business Day;

                           (B) any Interest Period pertaining to a LIBOR Rate
         Loan that begins on the last Business Day of a calendar month (or on a
         day for which there is no numerically corresponding day in the calendar
         month at the end of such Interest Period) shall end on the last
         Business Day of the relevant calendar month;

                           (C) if the Borrower shall fail to give notice as
         provided above, the Borrower shall be deemed to have selected a Prime
         Loan to replace the affected LIBOR Rate Loan as provided herein;

                           (D) any Interest Period that would otherwise extend
         beyond the Termination Date shall end on the Termination Date; and

                           (E) no more than 6 LIBOR Rate Loans may be in effect
         at any time. For purposes hereof, LIBOR Rate Loans with different
         Interest Periods shall be considered as separate LIBOR Rate Loans, even
         if they shall begin on the same date and have the same duration,
         although borrowings, extensions and conversions may, in accordance with
         the provisions hereof, be combined at the end of existing Interest
         Periods to constitute a new LIBOR Rate Loan with a single Interest
         Period.

         "LIBOR" means the arithmetic mean (rounded to the nearest 1/100th of
1%) of the offered rates for deposits in U.S. dollars for a period equal to the
Interest Period selected which appears on the Telerate Page 3750 at
approximately 11:00 A.M. London time, two (2) Business Days prior to the
commencement of the applicable Interest Period. If, for any reason, such rate is
not available, then "LIBOR" shall mean the rate per annum at which, as
determined by the Bank, U.S. dollars in the amount of $5,000,000 are being
offered to leading banks at approximately 11:00 A.M. London time, two (2)
Business Days prior to the commencement of the applicable Interest Period for
settlement in immediately available funds by leading banks in the London
interbank market for a period equal to the Interest Period selected.

         "LIBOR Rate" means a rate per annum (rounded upwards, if necessary, to
the next higher 1/100th of 1%) determined by the Bank pursuant to the following
formula:

                  LIBOR Rate =                      LIBOR
                                    ------------------------------------
                                    1.00 - Eurodollar Reserve Percentage

         "LIBOR Rate Loan" means Loans hereunder bearing interest at a rate
determined by reference to the LIBOR Rate.

         "Lien" means any mortgage, pledge, hypothecation, assignment, security
interest, encumbrance, lien, preference or priority of any kind.

         "Loan" shall have the meaning given to such term in Section 2.1 hereof.

         "Person" means any individual, partnership, joint venture, firm,
corporation, limited liability company, association, trust or other enterprise
(whether or not incorporated) or any Governmental Authority.

         "Prime Loan" means Loans hereunder bearing interest at a rate
determined by reference to the Prime Rate.



                                       4
<PAGE>   5

         "Prime Rate" means the rate of interest per annum publicly announced
from time to time by the Bank as its prime rate in effect at its principal
office in Charlotte, North Carolina, with each change in the Prime Rate being
effective on the date such change is publicly announced as effective (it being
understood and agreed that the Prime Rate is a reference rate used by the Bank
in determining interest rates on certain loans and is not intended to be the
lowest rate of interest charged on any extension of credit by the Bank to any
debtor).

         "Pro Forma Basis" means, with respect to any transaction, that such
transaction shall be deemed to have occurred as of the first day of the four
fiscal quarter period ending as of the most recent fiscal quarter end preceding
the date of such transaction with respect to which the Bank has received annual
or quarterly financial statements and accompanying officer's certificate.

         "Requirement of Law" means, as to any Person, the certificate of
incorporation and by-laws or other organizational or governing documents of such
Person, and any law, treaty, rule or regulation or determination of an
arbitrator or a court or other Governmental Authority, in each case applicable
or any of its material property is subject.

         "Termination Date" means the date 364 days following the date of this
Note, or such later date not more than 364 days following the then applicable
Termination Date as to which the Bank may agree in its sole discretion.

         SECTION 2.  LOAN.

         2.1 Loan. During the Commitment Period, subject to the terms and
conditions hereof, the Bank agrees to make revolving loans to the Borrower upon
request up to an aggregate principal amount of FIFTY MILLION DOLLARS
($50,000,000) at any time outstanding. The loans hereunder may consist of Prime
Loans or LIBOR Rate Loans, or a combination thereof. The obligation of the Bank
to make loans hereunder and to extend, or convert loans into, LIBOR Rate Loans
is subject to the condition that the Representations and Warranties set forth
herein are true and correct in all material respects.

         2.2 Notices. Requests by the Borrower for loans hereunder, and for
extensions or conversions of loans hereunder, shall be made by written notice
(or telephone notice promptly confirmed in writing) by 12:00 Noon Charlotte,
North Carolina time on the Business Day of the requested borrowing, extension or
conversion. Each request shall be in a minimum principal amount of $1,000,000 in
the case of LIBOR Rate Loans and $100,000 in the case of Prime Loans and, in
each case, integral multiples of $100,000 in excess thereof, and shall specify
the date of the requested borrowing, extension or conversion, the aggregate
amount to be borrowed, extended or converted and if an extension of conversion,
the loan which is being extended or converted, and whether the borrowing,
extension or conversion shall consist of LIBOR Rate Loans, Prime Loans or
combination thereof. If the Borrower shall fail to specify (A) the type of Loan
requested for a borrowing, the request shall be deemed a request for a LIBOR
Rate Loan with an Interest Period of one month, (B) the duration of the
applicable Interest Period in the case of LIBOR Rate Loans, the request shall be
deemed to be a request for an Interest Period of one month. Each request for a
borrowing, extension or conversion hereunder shall be deemed a reaffirmation
that the Representations and Warranties set forth herein are true and correct in
all material respects as of such date. Unless extended in accordance with the
provisions hereof, LIBOR Rate Loans shall be converted to Prime Loans at the end
of the applicable Interest Period.

         2.3 Interest Rate. Loans outstanding hereunder shall bear interest at a
per annum rate equal to (i) the LIBOR Rate plus three-quarters of one percent
(.75%) or (ii) the Prime Rate, as the Borrower may elect; provided that after
the occurrence and during the continuance of an Event of Default, the principal
and, to the extent permitted by law, interest on the Loan and any other amounts
owing hereunder shall bear interest, payable on demand, at a rate equal to the
Prime Rate plus three percent (3%). Interest will be payable in arrears on each
Interest Payment Date.


                                       5
<PAGE>   6


         2.4 Repayment. Unless sooner paid, the Loan shall be due and payable in
full on the Termination Date.

         2.5 Note. The Loan shall be evidenced by a promissory note of the
Borrower dated as of the Closing Date, in the form of Annex A hereto (as
amended, modified, extended, renewed or replaced, the "Note").

         2.6 Facility Fee. In consideration of the commitments hereunder, the
Borrower agrees to pay to the Bank a facility fee (the "Facility Fee") equal to
ten basis points (.10%) per annum on the average daily unused portion of the
commitment for the applicable period. The Facility Fee shall be payable
quarterly in arrears on the 15th day following the last day of each calendar
quarter for the immediately preceding quarter (or portion thereof) beginning
with the first such date to occur after the date hereof.

         2.7 Prepayments. The Loans may be prepaid in whole or in part without
premium or penalty. LIBOR Rate Loans may not be prepaid in whole or in part
prior to the end of the applicable Interest Period. Amounts prepaid may, subject
to the terms and conditions hereof, be reborrowed.

         2.8 Capital Adequacy. If the Bank shall have reasonably determined that
the adoption of or any change in any Requirement of Law regarding capital
adequacy or in the interpretation or application thereof as a consequence of its
obligations hereunder or compliance by the Bank or any corporation controlling
the Bank with any request or directive regarding capital adequacy (whether or
not having the force of law) from any central bank or Governmental Authority
made subsequent to the date hereof as a consequence of its obligations hereunder
does or shall have the effect of reducing the rate of return on the Bank's or
such corporation's capital as a consequence of its obligations hereunder to a
level below that which the Bank or such corporation could have achieved but for
such adoption, change or compliance (taking into consideration the Bank's or
such corporation's policies with respect to capital adequacy) by an amount
reasonably deemed by the Bank to be material, then from time to time, within 15
days after demand by the Bank, the Borrower shall pay to the Bank such
additional amount as shall be certified by the Bank as being required to
compensate it for such reduction. Such a certificate as to any additional
amounts payable under this subsection submitted by the Bank (which certificate
shall include a description in reasonable detail of the basis for the
computation) to the Borrower shall be conclusive absent manifest error.

         2.9 Inability to Determine Interest Rate. Notwithstanding any other
provision of this Agreement, if (i) the Bank shall reasonably determine (which
determination shall be conclusive and binding absent manifest error) that, by
reason of circumstances affecting the relevant market, reasonable and adequate
means do not exist for ascertaining LIBOR for such Interest Period, or (ii) the
Bank shall reasonably determine (which determination shall be conclusive and
binding absent manifest error) that the LIBOR Rate does not adequately and
fairly reflect the cost of funding LIBOR Rate Loans, the Bank shall forthwith
give telephone notice of such determination, confirmed in writing, to the
Borrower, and thereafter the right to request and continue Loans as LIBOR Rate
Loans shall be suspended until such time as the conditions giving rise to such
notice shall no longer exist. In the event LIBOR Rate Loans are not available on
account of operation of this Section, the Bank will endeavor to provide an
alternative index or reference rate.

         2.10 Illegality. Notwithstanding any other provision of this Agreement,
if the adoption of or any change in any Requirement of Law or in the
interpretation or application thereof, in each case occurring after the Closing
Date, by the relevant Governmental Authority shall make it unlawful for the Bank
to make or maintain LIBOR Rate Loans as contemplated by this Agreement or to
obtain in the interbank eurodollar market through its LIBOR Lending Office the
funds with which to make such Loans, (a) the Bank shall promptly notify the
Borrower thereof, (b) the commitment of the Bank hereunder to make LIBOR Rate
Loans or continue LIBOR Rate Loans as such shall forthwith be suspended until
the Bank shall give notice that the condition or situation which gave 



                                       6
<PAGE>   7

rise to the suspension shall no longer exist, and (c) Loans then outstanding as
LIBOR Rate Loans, if any, shall be converted on the last day of the Interest
Period for such Loans or within such earlier period as required by law to Prime
Loans. The Borrower hereby agrees promptly to pay the Bank, upon its demand,
any additional amounts necessary to compensate the Bank for actual and direct
costs (but not including anticipated profits) reasonably incurred in making any
repayment in accordance with this subsection including, but not limited to, any
interest or fees payable by the Bank to lenders of funds obtained by it in
order to make or maintain its LIBOR Rate Loans hereunder. A certificate as to
any additional amounts payable pursuant to this subsection submitted by the
Bank, to the Borrower shall be conclusive in the absence of manifest error.

         2.11 Requirements of Law. If the adoption of or any change in any 
Requirement of Law or in the interpretation or application thereof or
compliance by the Bank with any request or directive (whether or not having the
force of law) from any central bank or other Governmental Authority, in each
case made subsequent to the date hereof:

                  (i) shall subject the Bank to any tax of any kind whatsoever
         with respect to any LIBOR Rate Loan made by it, or change the basis of
         taxation of payments to the Bank in respect thereof (except for changes
         in the rate of tax on the net income or franchise tax applicable to the
         Bank);

                  (ii) shall impose, modify or hold applicable any reserve,
         special deposit, compulsory loan or similar requirement against assets
         held by, deposits or other liabilities in or for the account of,
         advances, loans or other extensions of credit by, or any other
         acquisition of funds by, any office of the Bank which is not otherwise
         included in the determination of the LIBOR Rate hereunder; or

                  (iii) shall impose on the Bank any other condition (excluding
         any tax of any kind whatsoever); 

and the result of any of the foregoing is to increase the cost to the Bank of
making or maintaining LIBOR Loans or to reduce any amount receivable hereunder
or under the Note, then, in any such case, the Borrower shall promptly pay the
Bank, within 15 days after its demand, any additional amounts necessary to
compensate the Bank for such additional cost or reduced amount receivable as
determined by the Bank with respect to its LIBOR Rate Loans. A certificate as to
any additional amounts payable pursuant to this subsection submitted by the
Bank, describing in reasonable detail the nature of such event and a reasonably
detailed explanation of the calculation thereof, to the Borrower shall be
conclusive in the absence of manifest error.

         2.12 Indemnity. The Borrower hereby agree to indemnify the Bank and to
hold the Bank harmless from any funding loss or expense which the Bank may
sustain or incur (other than as a result of and to the extent the Bank's gross
negligence or willful misconduct) as a consequence of (a) default by the
Borrower in payment of the principal amount of or interest on any LIBOR Rate
Loan by the Bank in accordance with the terms hereof, (b) default by the
Borrower in accepting a LIBOR Rate Loan after the Borrower have given a notice
in accordance with the terms hereof, (c) default by the Borrower in making any
prepayment of a LIBOR Rate Loan after the Borrower have given a notice in
accordance with the terms hereof, and/or (d) the making by the Borrower of a
prepayment of a LIBOR Rate Loan, or the conversion thereof, on a day which is
not the last day of the Interest Period with respect thereto, in each case equal
to (i) the amount of interest which would have accrued on the amount so prepaid,
or not so paid, borrowed, converted or continued, for the period from the date
of such prepayment or of such failure to borrow, convert or continue to the last
day of such Interest Period (or, in the case of a failure to pay, borrow,
convert or continue, the Interest Period that would have commenced on the date
of such failure), in each case at the applicable rate of interest for such Loans
provided for herein (exclusive of any margin), over (ii) the amount of interest
(as reasonably determined by the Bank) which would have accrued to the Bank on
such amount by placing such amount on deposit for a comparable period with
leading banks in the interbank eurodollar market. A certificate as to any
additional amounts payable


                                       7
<PAGE>   8

pursuant to this subsection submitted by the Bank, to the Borrower shall be
conclusive in the absence of manifest error

         2.13 Taxes. All payments made by the Borrower hereunder or under any
Note will be made free and clear of, and without deduction or withholding for,
any present or future taxes, levies, imposts, duties, fees, assessments or other
charges of whatever nature now or hereafter imposed by any Governmental
Authority or by any political subdivision or taxing authority thereof or therein
with respect to such payments (but excluding (i) any tax imposed on or measured
by the net income or profits of a Lender pursuant to the laws of the
jurisdiction in which it is organized or the jurisdiction in which the principal
office or applicable lending office of the Bank is located or any subdivision
thereof or therein and (ii) any franchise taxes, branch taxes, taxes on doing
business or taxes on the overall capital or net worth of the Bank pursuant to
the laws of the jurisdiction in which it is organized or the jurisdiction in
which the principal office or its applicable lending office is located or any
subdivision thereof or therein) and all interest, penalties or similar
liabilities with respect thereto (all such non-excluded taxes, levies, imposts,
duties, fees, assessments or other charges being referred to collectively as
"Taxes"). If any Taxes are so levied or imposed, the Borrower agrees to pay the
full amount of such Taxes, and such additional amounts as may be necessary so
that every payment of all amounts due under this Agreement or under any Note,
after withholding or deduction for or on account of any such Taxes, will not be
less than the amount provided for herein or in such Note. The Borrower will
furnish to the Bank as soon as practicable after the date the payment of any
Taxes is due pursuant to applicable law certified copies (to the extent
reasonably available and required by law) of tax receipts evidencing such
payment by the Borrower. The Borrower agrees to indemnify and hold harmless, and
reimburse, the Bank upon its written request, for the amount of any Taxes so
levied or imposed and paid by the Bank. The agreements in this subsection shall
survive termination of this Agreement and payment of the Notes and all other
amounts payable hereunder.

         2.14 Payments and Computations. Payments shall be made hereunder in
U.S. dollars in immediately available funds, without offset, deduction,
counterclaim or withholding of any kind at the offices of the Bank provided in
the notice section hereof. Payments received after 2:00 P.M. (Charlotte, North
Carolina time) will be given credit the next following Business Day.
Computations of interest hereunder shall be made on the basis of actual number
of days elapsed over a year of 360 days.

         SECTION 3.  GUARANTY

         3.1 Guaranty. Each of the Guarantors hereby jointly and severally
guarantees to the Bank as hereinafter provided the prompt payment of the
Guaranteed Obligations in full when due (whether at stated maturity, as a
mandatory prepayment, by acceleration or otherwise and after giving effect to
any grace periods) strictly in accordance with the terms hereof. Each of the
Guarantors hereby further agrees that if any of the Guaranteed Obligations are
not paid in full when due (whether at stated maturity, as a mandatory
prepayment, by acceleration or otherwise and after giving effect to any grace
periods), the Guarantor will promptly pay the same, without any demand or notice
whatsoever, and that in the case of any extension of time of payment or renewal
of any of the Guaranteed Obligations, the same will be promptly paid in full
when due (whether at extended maturity, as a mandatory prepayment, by
acceleration or otherwise and after giving effect to any grace periods) in
accordance with the terms of such extension or renewal. This is a guaranty of
payment and not of collection.

         Notwithstanding any provision to the contrary contained herein or in
any other of the Credit Documents, to the extent the obligations of any
Guarantor as guarantor hereunder shall be adjudicated to be invalid or
unenforceable for any reason (including, without limitation, because of any
applicable state or federal law relating to fraudulent conveyances or transfers)
then the obligations of such Guarantor hereunder shall be limited to the maximum
amount that is permissible under applicable law (whether federal or state and
including, without limitation, the Bankruptcy Code).


                                       8
<PAGE>   9


         3.2 Obligations Unconditional. The obligations of the Guarantors under
Section 3.1 hereof are absolute and unconditional, irrespective of the value,
genuineness, validity, regularity or enforceability of this Agreement or the
Note, or any other agreement or instrument referred to herein or therein or
relating hereto or thereto, or any substitution, release or exchange of any
other guarantee of or security for any of the Guaranteed Obligations, and, to
the fullest extent permitted by applicable law, irrespective of any other
circumstance whatsoever which might otherwise constitute a legal or equitable
discharge or defense of a surety or guarantor, it being the intent of this
Section 3.2 that the obligations of the Guarantors hereunder shall be absolute
and unconditional under any and all circumstances. Each of the Guarantors agrees
that it shall have no right of subrogation, indemnity, reimbursement or
contribution against the Borrower or any other guarantor for amounts paid under
this Guaranty until such time as the Bank has been paid in full, all
commitments, if any, have been terminated and no Person or Governmental
Authority shall have any right to request any return or reimbursement of funds
from the Bank in connection with monies received under the Credit Documents.
Without limiting the generality of the foregoing, it is agreed that, to the
fullest extent permitted by law, the occurrence of any one or more of the
following shall not alter or impair the liability of the Guarantors hereunder
which shall remain absolute and unconditional as described above:

                  (i) at any time or from time to time, without notice to the
         Guarantors, the time for any performance of or compliance with any of
         the Guaranteed Obligations shall be extended, or such performance or
         compliance shall be waived;

                  (ii) any of the acts mentioned in any of the provisions of
         this Agreement or the Note or any other agreement or instrument
         referred to herein or therein or relating hereto or thereto shall be
         done or omitted;

                  (iii) the maturity of any of the Guaranteed Obligations shall
         be accelerated, or any of the Guaranteed Obligations shall be modified,
         supplemented or amended in any respect, or any right under any of the
         Credit Documents or any other agreement or instrument referred to in
         the Credit Documents shall be waived or any other guarantee of any of
         the Guaranteed Obligations or any security therefor shall be released
         or exchanged in whole or in part or otherwise dealt with;

                  (iv) any Lien granted to, or in favor of, the Bank as security
         for any of the Guaranteed Obligations shall fail to attach or be
         perfected or shall be released or discharged in whole or in part; or

                  (v) any of the Guaranteed Obligations shall be determined to
         be void or voidable (including, without limitation, for the benefit of
         any creditor of any Guarantor or any other guarantor) or shall be
         subordinated to the claims of any Person (including, without
         limitation, any creditor of any guarantor).

With respect to its obligations hereunder, each of the Guarantors hereby
expressly waives diligence, presentment, demand of payment, protest and all
notices whatsoever, and any requirement that the Bank exhaust any right, power
or remedy or proceed against any Person under this Agreement or the Note or any
other agreement or instrument referred to herein or therein or relating hereto
or thereto, or against any other Person under any other guarantee of, or
security for, any of the Guaranteed Obligations.

         3.3 Reinstatement. The obligations of the Guarantors under this Section
3 shall be automatically reinstated if and to the extent that for any reason any
payment by or on behalf of any Person in respect of the Guaranteed Obligations
is rescinded or must be otherwise restored by any holder of any of the
Guaranteed Obligations, whether as a result of any proceedings in bankruptcy or
reorganization or otherwise, and each of the Guarantors agrees that it will
indemnify the Bank on demand for all reasonable costs and expenses (including,
without limitation, fees and expenses of counsel) incurred by the Bank in
connection with such rescission or restoration, including any such


                                       9
<PAGE>   10


costs and expenses incurred in defending against any claim alleging that such
payment constituted a preference, fraudulent transfer or similar payment under
any bankruptcy, insolvency or similar law.

         3.4 Certain Additional Waivers. Without limiting the generality of the
provisions of this Section 3, each of the Guarantors hereby specifically waives
the benefits of N.C. Gen. Stat. Sec. 26-7 through 26-9, inclusive. Each of the
Guarantors agrees that it shall have no right of recourse to security for the
Guaranteed Obligations, except through the exercise of the rights of subrogation
pursuant to Section 3.2.

         3.5 Remedies. Each of the Guarantors agrees that, to the fullest extent
permitted by law, as between the Guarantors, on the one hand, and the Bank, on
the other hand, the Guaranteed Obligations may be declared to be forthwith due
and payable as provided in Section 7.2 hereof (and shall be deemed to have
become automatically due and payable in the circumstances provided in said
Section 7.2) for purposes of Section 3.1 hereof notwithstanding any stay,
injunction or other prohibition preventing such declaration (or preventing the
Guaranteed Obligations from becoming automatically due and payable) as against
any other Person and that, in the event of such declaration (or the Guaranteed
Obligations being deemed to have become automatically due and payable), the
Guaranteed Obligations (whether or not due and payable by any other Person)
shall forthwith become due and payable by the Guarantors for purposes of said
Section 3.1.

         3.6 Continuing Guarantee. The guarantee in this Section 3 is a
continuing guarantee, and shall apply to all Guaranteed Obligations whenever
arising.

         3.7 Rights of Contribution. The Guarantors hereby agree, as among
themselves, that if any Guarantor shall become an Excess Funding Guarantor (as
defined below), each other Guarantor shall, on demand of such Excess Funding
Guarantor (but subject to the succeeding provisions of this Section), pay to
such Excess Funding Guarantor an amount equal to such Guarantor's Pro Rata Share
(as defined below and determined, for this purpose, without reference to the
properties, assets, liabilities and debts of such Excess Funding Guarantor) of
such Excess Payment (as defined below). The payment obligation of any Guarantor
to any Excess Funding Guarantor under this Section shall be subordinate and
subject in right of payment to the prior payment in full of the obligations of
such Guarantor under the other provisions of this Section 3, and such Excess
Funding Guarantor shall not exercise any right or remedy with respect to such
excess until payment and satisfaction in full of all of such obligations. For
purposes hereof, (i) "Excess Funding Guarantor" shall mean, in respect of any
obligations arising under the other provisions of this Section 3 (hereafter, the
"Guarantied Obligations"), a Guarantor that has paid an amount in excess of its
Pro Rata Share of the Guarantied Obligations; (ii) "Excess Payment" shall mean,
in respect of any Guarantied Obligations, the amount paid by an Excess Funding
Guarantor in excess of its Pro Rata Share of such Guarantied Obligations; and
(iii) "Pro Rata Share", for the purposes of this Section, shall mean, for any
Guarantor, the ratio (expressed as a percentage) of (a) the amount by which the
aggregate present fair saleable value of all of its assets and properties
exceeds the amount of all debts and liabilities of such Guarantor (including
contingent, subordinated, unmatured, and unliquidated liabilities, but excluding
the obligations of such Guarantor hereunder) to (b) the amount by which the
aggregate present fair saleable value of all assets and other properties of the
Borrower and all of the Guarantors exceeds the amount of all of the debts and
liabilities (including contingent, subordinated, unmatured, and unliquidated
liabilities, but excluding the obligations of the Borrower and the Guarantors
hereunder) of the Borrower and all of the Guarantors, all as of the Closing Date
(if any Guarantor becomes a party hereto subsequent to the Closing Date, then
for the purposes of this Section such subsequent Guarantor shall be deemed to
have been a Guarantor as of the Closing Date and the information pertaining to,
and only pertaining to, such Guarantor as of the date such Guarantor became a
Guarantor shall be deemed true as of the Closing Date).

         3.8 Joinder of Additional Guarantors. The Borrower may join additional
subsidiaries as Guarantors hereunder by way of execution of a Joinder Agreement,
a form of which is attached as Annex C.


                                       10
<PAGE>   11


         SECTION 4  CONDITIONS TO CLOSING

         4.1 Conditions. The effectiveness of this Agreement and extension of
the Loan hereunder are conditioned upon satisfaction of the following:

                  (a) Receipt of multiple executed counterparts of this
Agreement and the Note, in form and substance satisfactory to the Bank.

                  (b) Receipt of opinions of the general counsel for the
Borrower and the Guarantors in the form attached as Annex D hereto.

                  (c) Receipt of corporate documentation for the Credit Parties,
including resolutions, bylaws, articles of incorporation, certificates of good
standing and certificates of incumbency.

         SECTION 5  REPRESENTATIONS AND WARRANTIES

         5.1 Financial Condition. The consolidated balance sheet of the Borrower
and its consolidated subsidiaries dated as of December 31, 1996 together with
related consolidated statements of income and cash flows, are complete and
correct in all material respects and present fairly the financial condition and
results from operations of the entities and for the periods specified, subject
in the case of interim company-prepared statements to normal year-end
adjustments.

         5.2 No Change. Since the date of the financial statements identified
above, there have been no developments or events which have had, or are likely
to have, a material adverse effect on the Borrower or on the condition
(financial or otherwise), operations, business or prospects of the Borrower and
its subsidiaries taken as a whole.

         5.3 Corporate Organization. Each of the Credit Parties is a corporation
duly organized, validly existing and in good standing under the laws of the
State of its incorporation, is qualified to do business in each jurisdiction
where failure to so qualify would have a material adverse effect on the Borrower
and its subsidiaries taken as a whole and is in compliance with all Requirements
of Law except to the extent that failure to be in compliance would not have a
material adverse effect on the Borrower and its subsidiaries taken as a whole.

         5.4 Enforceable Obligation. Each of the Credit Parties has the power
and authority and legal right to enter into, deliver and perform under this
Agreement and has taken all necessary action to authorize the execution,
delivery and performance by them of this Agreement. This Agreement constitutes a
legal, valid and binding obligation of each of the Credit Parties enforceable
against them in accordance with its terms except as enforceability may be
limited by applicable bankruptcy, insolvency, reorganization, moratorium or
similar laws affecting the enforcement of creditors' rights generally or by
general equitable principles (whether enforcement is sought by proceedings in
equity or at law).

         5.5 Legal Proceedings. No claim, litigation or proceeding before any
arbitrator or Governmental Authority is pending, or to the knowledge of the
Credit Parties, threatened which if adversely determined would reasonably be
expected to have a material adverse effect on the Borrower and its subsidiaries
taken as a whole.

         5.6 No Default. No Event of Default or event or condition which with
notice or lapse of time, or both, would constitute an Event of Default,
presently exists.

         5.7 Federal Regulations. No part of the proceeds of the Loan hereunder
will be used, directly or indirectly, for any purpose in violation of Regulation
U of the Board of Governors of the Federal Reserve System, as amended, modified
or replaced.


                                       11
<PAGE>   12


         SECTION 6  COVENANTS

         The Borrower and the Guarantors covenant and agree to:

         6.1 Financial Statements. Furnish, or cause to be furnished, to the
Bank:

                  (a) Annual Audited Statements. As soon as available, but in
         any event within 90 days after the end of each fiscal year, audited
         consolidated and company-prepared consolidating balance sheets of the
         Borrower and its subsidiaries and related statements audited
         consolidated and company-prepared consolidating statements of income,
         retained earnings and cash flows, audited by Coopers & Lybrand, or
         other independent public accounting firm reasonably acceptable to the
         Bank, setting forth comparative information for the previous year, and
         reported without a "going concern" or like qualification or exception,
         or qualification indicating limitation of the scope of the audit; and

                  (b) Quarterly Statements. As soon as available, and in any
         event within 45 days after the end of each fiscal quarter, a
         company-prepared consolidated and consolidating balance sheet of the
         Borrower and its subsidiaries and related company-prepared consolidated
         and consolidating statements of income, retained earnings and cash
         flows for the quarter and for the portion of the year with comparative
         information for the corresponding periods for the previous year.

All such financial statements to be complete and correct in all material
respects (subject, in the case of interim statements, to normal recurring
year-end audit adjustments) and to be prepared in reasonable detail and in
accordance with GAAP throughout the periods reflected therein (except as
approved by such accountants and disclosed therein) and further accompanied by a
description of, and an estimation of the effect on the financial statements on
account of, a change in the application of accounting principles from a prior
period.

                  (c) Other Information. Promptly upon request, such additional
         financial and other information as the Bank may reasonably request from
         time to time.

         6.2 Certificates and Notices. Furnish, or cause to be furnished, and
give notice to the Bank:

                  (a) Officer's Certificate. Concurrently with the annual and
         quarterly financial statements referenced above, a certificate of a
         responsible officer of the Borrower stating that to the best of his
         knowledge and belief, (i) the financial statements fairly present in
         all material respects the financial condition of the parties to which
         such statements relate and (ii) the Borrower and the Guarantors are in
         compliance with the provisions of this Agreement in all material
         respects and no Event of Default, or event or condition which with
         notice or lapse of time, or both, would constitute an Event of Default
         exists hereunder (together with a financial covenant calculation
         worksheet demonstrating compliance therewith in reasonable detail).

                  (b) Public and Other Information. Copies of reports and
         information which the Borrower or its subsidiaries sends to its
         stockholders or files with the Securities and Exchange Commission, and
         any other financial or other information as the Bank may reasonably
         request.

                  (c) Notice of Default. Promptly, upon becoming aware thereof,
         notice of the occurrence of an Event of Default hereunder.

         6.3 Compliance with Laws. Comply will all Requirements of Law
applicable to them except to the extent that failure to comply therewith would
not have a material adverse effect on the Borrower and its subsidiaries taken as
a whole.


                                       12
<PAGE>   13


         6.4 Books and Records. The Credit Parties will keep proper books and
records in conformity with GAAP and all Requirements of Law and permit the Bank
upon reasonable notice to visit and inspect such books and records.

         6.5 Financial Covenants.

                  (a) Consolidated Tangible Net Worth. Consolidated Tangible Net
         Worth shall not at any time be less than the sum of $75 million plus at
         the end of each fiscal quarter occurring after March 31, 1997, 50% of
         Consolidated Net Income (but not less than zero) for the fiscal quarter
         then ended, such increases to be cumulative.

                  (b) Consolidated Fixed Charge Coverage Ratio. As of the last
         day of each fiscal quarter, the Consolidated Fixed Charge Coverage
         Ratio shall be not less than 2.0:1.0.

                  (c) Consolidated Debt to Total Capitalization Ratio. The
         Consolidated Debt to Total Capitalization Ratio shall not at any time
         be greater than .45:1.0.

         6.6 Incurrence of Funded Debt. The Borrower will not, nor will it
permit any of its subsidiaries to, create, assume, incur or suffer to exist any
Funded Debt except:

                  (a) capital lease obligations and Funded Debt incurred to
         provide all or a portion of the purchase price or cost of construction
         of an asset, provided that (i) such Debt when incurred will not exceed
         the purchase price or cost of construction of the asset , and (ii) no
         such Debt shall be refinanced for a principal amount in excess of the
         principal balance outstanding thereon at the time of such refinancing;
         and

                  (b) other Funded Debt of the Borrower not to exceed
         $50,000,000.

         6.7 Restriction on Liens. The Borrower will not, nor will it permit any
of its subsidiaries to, create, assume, incur or suffer to exist any Lien on any
property or asset of any kind, real or personal, tangible or intangible, now
owned or hereafter acquired by it or assign or subordinate any present or future
right to receive assets except:

                  (a) Liens securing capital lease obligations and other
         purchase money Funded Debt permitted under Section 6.6(a);

                  (b) Liens securing taxes, assessments or governmental charges
         or levies or the claims or demands of materialmen, mechanics, carriers,
         warehousemen, landlords and other like persons; provided that (A) with
         respect to Liens securing state and local taxes, such taxes are not yet
         payable, (b) with respect to Liens securing claims or demands of
         materialmen, mechanics, carriers, warehousemen, landlords and the like,
         such liens are unfiled and no other action has been taken to enforce
         the same, or (C) with respect to taxes, assessments or governmental
         charges or levies or claims or demand secured by such Liens, payment is
         not at the time required;

                  (c) Liens not securing indebtedness which are incurred in the
         ordinary course of business in connection with workmen's compensation,
         unemployment insurance, unemployment insurance, social security and
         other like laws;

                  (d) any Lien arising pursuant to any order of attachment,
         distraint or similar legal process arising in connection with court
         proceedings so long as the execution or other enforcement thereof is
         effectively stayed and the claims secured thereto are being contested
         in good faith by appropriate proceedings; and


                                       13
<PAGE>   14


                  (e) zoning restrictions, easements, licenses, reservations,
         covenants, conditions, waivers, restrictions on the use of property or
         other minor encumbrances or irregularities of title which do not
         materially impair the use of any property in the operation or business
         of the Borrower or such subsidiary or the value of such property for
         the purpose of such business.

         6.8 Mergers and Acquisitions. The Borrower will not, nor will it permit
any of its subsidiaries to, enter into a transaction of merger or consolidation,
nor will it acquire all or substantially all of the capital stock (or other
equity interest) or assets of any other Person, except:

                  (a) in the case of transactions of mergers and consolidation,
         (i) if a Credit Party is a party to the transaction, it shall be the
         surviving corporation, (ii) if the Borrower is a party to the
         transaction, it shall be the surviving corporation, and (iii) if the
         transaction is with a Person other than the Borrower or any of its
         subsidiaries, the Borrower shall demonstrate compliance with the
         financial covenants on a Pro Forma Basis; and

                  (b) in all other cases, the Borrower shall demonstrate
         compliance with the financial covenants on a Pro Forma Basis.

         6.9 Investments. The Borrower will not, nor will it permit any of its
subsidiaries to, make loans or advances or otherwise make an investment in or
capital contribution to, (collectively, an "Investment") any other Person,
except:

                  (a) cash and cash equivalents and other publicly traded equity
         and debt instruments reasonably acceptable to the Bank;

                  (b) loans and advances to officers, directors, employees and
         shareholders not to exceed $2,000,000;

                  (c) Investments in and to a Credit Party; and

                  (d) other Investments in an aggregate principal amount (on a
         cost basis) at any time of up to $5,000,000.

         SECTION 7  EVENTS OF DEFAULT

         7.1 Event of Default. Each of the following shall constitute an "Event
of Default" hereunder: (i) the failure to make any payment of principal,
interest, fees or other amounts owing hereunder when due, (ii) any
representation or warranty made herein or in connection herewith shall prove to
be false or incorrect in any material respect, (iii) failure to observe or
comply with any covenants or provisions contained herein, (iv), the occurrence
and continuance of an event of default under any other note or agreement
relating to indebtedness for borrowed money owing by the Borrower or any
Guarantor which results in, or would permit, acceleration of such indebtedness,
or would otherwise cause such indebtedness to become due prior to its stated
maturity, (v) the filing of an action in bankruptcy or insolvency by the
Borrower or any Guarantor, (vi) the filing of an action in bankruptcy or
insolvency against the Borrower or any Guarantor and (vii) the Borrower or any
Guarantor shall fail within 30 days of the due date to pay bond or otherwise
discharge any judgment, settlement or order.

         7.2 Remedies. Upon the occurrence of an Event of Default, and at any
time thereafter, the Bank may by notice to the Borrower (i) declare the unpaid
principal of, and any accrued interest owing on, the Loan and all other
indebtedness or obligations owing hereunder or under any of the other Credit
Documents or in connection herewith or therewith, immediately due and payable,
whereupon the same shall be immediately due and payable without presentment,
demand, protest or other notice of any kind, all of which are hereby waived by
the Borrower, and (ii) enforce any other rights and interests available under
the Credit Documents or at law, including rights of set off.


                                       14
<PAGE>   15


Notwithstanding the foregoing, in the case of an Event of Default described in
clauses (v) or (vi) of Section 7.1 relating to bankruptcy and insolvency, the
Loan and all accrued interest and all other indebtedness and other amounts owing
hereunder or under any of the other Credit Documents owing to the Bank shall
become immediately due and payable without presentment, demand, protest or the
giving of any notice or other action by the Bank, all of which are hereby waived
by the Borrower.

         SECTION 8  MISCELLANEOUS

         8.1 Notices. Notices and other communications shall be effective, and
duly given, (i) when received, (ii) when transmitted by telecopy or other
facsimile device to the numbers set out below if transmitted before 5:00 p.m. on
a Business Day, or otherwise on the next following Business Day, (iii) the day
following the day on which delivered prepaid to a reputable national overnight
air courier service, or (iv) the third Business Day following the day sent by
certified or registered mail postage prepaid, in each case to the parties at the
address shown below, or at such other address as may be specified by written
notice to the other parties:

                  Borrower:     Pharmaceutical Product Development, Inc.
                                3151 17th Street Extension
                                Wilmington, North Carolina  28412
                                Attn:    Rudy Howard
                                Phone:   (910) 772-6860
                                Fax:     (910) 772-7056

                  Bank:         FIRST UNION NATIONAL BANK OF NORTH CAROLINA
                                Corporate Banking, 6th Floor
                                150 Fayetteville Street Mall
                                Raleigh, North Carolina  27601
                                Attn:    Mendel Lay
                                Phone:   (919) 829-6064
                                Fax:     (919) 829-6067

         8.2 Right of Set-Off. In addition to other rights now or hereafter
available to the Bank under the Credit Documents or under applicable law, the
Bank may, after the occurrence of an Event of Default, exercise rights of
set-off and may appropriate and apply any and all deposits (general and
specific) or other amounts held or owing by the Bank to the Loan and other
amounts owing by the Borrower or any Guarantor hereunder or under the other
Credit Documents, regardless of whether the Loan or such other amounts are
contingent or unmatured, without presentment, demand, protest or notice of any
kind (any such rights of presentment, demand, protest or notice being hereby
waived).

         8.3 Benefit of Agreement. This Agreement shall be binding upon, and
shall inure to the benefit of, successors and assigns of the parties hereto;
provided that neither the Borrower nor any Guarantor may assign or transfer any
its obligations or interests without prior written consent of the Bank.

         8.4 No Waiver. No failure or delay on the part of the Bank in
exercising any right, power or privilege hereunder or under any other Credit
Document and no course of dealing between the Bank, on the one hand, and the
Credit Parties, on the other hand, shall operate as a waiver thereof; nor shall
any single or partial exercise of any right, power or privilege hereunder or
under any other Credit Document preclude any other or further exercise thereof
or the exercise of any other right, power or privilege hereunder or thereunder.
The rights and remedies provided herein are cumulative and not exclusive of any
rights or remedies which the Bank would otherwise have.

         8.5 Payment of Expenses. The Borrower agrees to: (i) pay all reasonable
out-of-pocket costs and expenses of the Bank in connection with (A) negotiation,
preparation, execution and


                                       15
<PAGE>   16


delivery of the Credit Documents (including reasonable fees and expenses of Bank
counsel, Moore & Van Allen, PLLC) and any amendments, waivers or consents
relating to the Credit Documents and (B) enforcement of the Credit Documents and
the documents and instruments referred to therein (including, without
limitation, in connection with any such enforcement, the reasonable fees and
disbursements of counsel for the Bank); (ii) pay and hold the Bank harmless from
and against any and all present and future stamp and other similar taxes with
respect to the foregoing matters and save the Bank harmless from and against any
and all liabilities with respect to or resulting from any delay or omission
(other than to the extent attributable to the Bank) to pay such taxes; and (iv)
indemnify the Bank, its officers, directors, employees and representatives from
and hold each of them harmless against any and all losses, liabilities, claims,
damages or expenses incurred by any of them as a result of, or arising out of,
or in any way related to, or by reason of any investigation, litigation or other
proceeding (whether or not the Bank is a party thereto) related to the entering
into and/or performance of any Credit Document or the use of proceeds of the
Loan (including other extensions of credit) hereunder or the consummation of any
other transactions contemplated in any Credit Document, including, without
limitation, the reasonable fees and disbursements of counsel incurred in
connection with any such investigation, litigation or other proceeding (but
excluding any such losses, liabilities, claims, damages or expenses to the
extent incurred by reason of gross negligence or willful misconduct on the part
of the Person to be indemnified).

         8.6 Amendments. Neither this Agreement nor any of the other Credit
Documents may be amended or modified, nor shall consents or waivers be effective
except with the written consent of the parties hereto.

         8.7 Counterparts. This Agreement may be executed in any number of
counterparts, each of which when so executed and delivered shall be an original,
but all of which shall constitute one and the same agreement. It shall not be
necessary in making proof of this Agreement to produce or account for more than
one such counterpart.

         8.8 Headings. The headings of the sections and subsections hereof are
provided for convenience only and shall not in any way affect the meaning or
construction of any provision of this Agreement.

         8.9 Survival. The indemnities and payment obligations hereunder,
including those set out in Sections 2.8, 2.9, 2.10, 2.11, 2.12, 2.13 and 8.5,
and the representations and warranties made herein or in connection herewith
shall survive the making and repayment of the Loan and termination of
commitments hereunder.

         8.10 Governing Law. This Agreement and the rights and obligations of
the parties hereunder shall be governed by and construed in accordance with the
laws of the State of North Carolina.

         8.11. Arbitration; Consent to Jurisdiction and Service of Process.

         (a) UPON DEMAND OF ANY PARTY HERETO, WHETHER MADE BEFORE OR AFTER
INSTITUTION OF ANY JUDICIAL ACTION, ANY DISPUTE, CLAIM OR CONTROVERSY ARISING
OUT OF OR CONNECTED HEREWITH OR WITH THE CREDIT DOCUMENTS ("DISPUTES") SHALL BE
RESOLVED BY BINDING ARBITRATION AS PROVIDED HEREIN. DISPUTES MAY INCLUDE,
WITHOUT LIMITATION, TORT CLAIMS, COUNTERCLAIMS, CLAIMS BROUGHT AS CLASS ACTIONS
AND CLAIMS ARISING HEREFROM OR FROM CREDIT DOCUMENTS EXECUTED IN THE FUTURE.
ARBITRATION SHALL BE CONDUCTED UNDER THE COMMERCIAL FINANCIAL DISPUTES
ARBITRATION RULES (THE "ARBITRATION RULES") OF THE AMERICAN ARBITRATION
ASSOCIATION AND TITLE 9 OF THE U.S. CODE. ALL ARBITRATION HEARINGS SHALL BE
CONDUCTED IN CHARLOTTE, MECKLENBURG COUNTY, NORTH CAROLINA, OR SUCH OTHER PLACE
AS AGREED TO IN WRITING BY THE PARTIES. A JUDGMENT UPON THE AWARD MAY BE ENTERED
IN ANY COURT HAVING JURISDICTION, AND ALL DECISIONS SHALL BE IN WRITING. THE
PANEL FROM WHICH ALL ARBITRATORS ARE SELECTED SHALL BE COMPRISED OF


                                       16
<PAGE>   17


LICENSED ATTORNEYS HAVING AT LEAST TEN YEARS' EXPERIENCE REPRESENTING PARTIES IN
SECURED LENDING TRANSACTIONS. NOTWITHSTANDING THE FOREGOING, THIS ARBITRATION
PROVISION DOES NOT APPLY TO DISPUTES UNDER OR RELATED TO INTEREST PROTECTION
AGREEMENTS.

         (b) Notwithstanding the preceding binding arbitration provision, the
Bank preserves certain remedies that may be exercised during a Dispute. The Bank
shall have the right to proceed in any court of proper jurisdiction or by self
help to exercise or prosecute the following remedies, as applicable: (i) all
rights to foreclose against any real or personal property or other security by
exercising a power of sale granted in the Credit Documents or under applicable
law, (ii) all rights of self help including peaceful occupation of real property
and collection of rents, set-off and peaceful possession of personal property,
(iii) obtaining provisional or ancillary remedies including injunctive relief,
sequestration, garnishment, attachment and appointment of receiver, (iv) when
applicable, a judgment by confession of judgment and (v) other remedies.
Preservation of these remedies does not limit the power of an arbitrator to
grant similar remedies that may be requested by a party in a Dispute.

         (c) BY EXECUTION AND DELIVERY OF THIS AGREEMENT, EACH OF THE PARTIES
HERETO ACCEPTS, FOR ITSELF AND IN CONNECTION WITH ITS PROPERTIES, GENERALLY AND
UNCONDITIONALLY, THE NON-EXCLUSIVE JURISDICTION RELATING TO ANY ARBITRATION
PROCEEDINGS CONDUCTED UNDER THE ARBITRATION RULES IN CHARLOTTE, MECKLENBURG
COUNTY, NORTH CAROLINA AND IRREVOCABLY AGREES TO BE BOUND BY ANY FINAL JUDGMENT
RENDERED THEREBY IN CONNECTION WITH THIS AGREEMENT FROM WHICH NO APPEAL HAS BEEN
TAKEN OR IS AVAILABLE. Each of the parties hereto irrevocably agrees that all
process in any such arbitration proceedings or otherwise may be effected by
mailing a copy thereof by registered or certified mail (or any substantially
similar form of mail), postage prepaid, to it at its address set forth in
Section 8.1 or at such other address of which such party shall have been
notified pursuant thereto, such service being hereby acknowledged by each party
hereto to be effective and binding service in every respect. Each party hereto
irrevocably waives any objection, including, without limitation, any objection
to the laying of venue or based on the grounds of forum non conveniens which it
may now or hereafter have to the bringing of any such arbitration proceeding in
any jurisdiction. Nothing herein shall affect the right to serve process in any
other manner permitted by law or shall limit the right of any party to bring
proceedings against the Borrower or any party hereto in any court or pursuant to
arbitration proceedings in any other jurisdiction.


                  [Remainder of Page Intentionally Left Blank]


                                       17
<PAGE>   18


         IN WITNESS WHEREOF, this Loan Agreement has been executed this day by
duly authorized officers of the undersigned parties.


BORROWER:                              PHARMACEUTICAL PRODUCT DEVELOPMENT, INC.,
                                       a North Carolina corporation

                                       By:  /s/ Rudy C. Howard
                                            -----------------------------
                                       Name: Rudy C. Howard
                                       Title: Chief Financial Officer


GUARANTORS:                            PPD PHARMACO, INC.,
                                       a Texas corporation

                                       By:  /s/ Rudy C. Howard
                                            -----------------------------
                                       Name: Rudy C. Howard
                                       Title: Vice President


                                       APBI ENVIRONMENTAL SCIENCES GROUP, INC.,
                                       a Virginia corporation

                                       By:  /s/ Rudy C. Howard
                                            -----------------------------
                                       Name: Rudy C. Howard
                                       Title: Vice President


BANK:                                  FIRST UNION NATIONAL BANK OF NORTH
                                       CAROLINA

                                       By:  /s/ Shannon S. Townsend
                                             -----------------------------
                                       Name:  Shannon S. Townsend
                                       Title:  Vice President




<PAGE>   19




                                 Promissory Note


$50,000,000                                             June 25, 1997


         PHARMACEUTICAL PRODUCT DEVELOPMENT, INC., a North Carolina corporation
(the "Borrower"), promises to pay to the order of FIRST UNION NATIONAL BANK OF
NORTH CAROLINA, its successor and assigns (the "Bank") on or before the
Termination Date the principal sum of FIFTY MILLION DOLLARS ($50,000,000) or, if
less, the aggregate unpaid principal amount of all Loans made by the Bank to the
Borrower, in lawful money of the United States in immediately available funds at
the office of the Bank as provided in the Loan Agreement referenced below or as
otherwise directed by the Bank pursuant to the terms of the Loan Agreement,
together with interest, in like money and funds, on the unpaid principal amount
hereof at the rates and on the dates as set forth in the Loan Agreement.

         This Note is issued pursuant to, and is entitled to the benefits of,
the Loan Agreement dated as of the date hereof (as the same may be amended or
modified and in effect from time to time, the "Loan Agreement") among the
Borrower, the Guarantors identified therein and the Bank, to which Loan
Agreement reference is hereby made for a statement of the terms and conditions
under which this Note may be prepaid or its maturity date accelerated.
Capitalized terms used herein and not otherwise defined herein are used with the
meanings attributed to them in the Loan Agreement.

         In the event payment of amounts due hereunder are accelerated under the
terms of the Loan Agreement, all such amounts shall become immediately due and
payable, without presentment, demand, protest or notice of any kind, all of
which are hereby waived. Further, in the event this Note is not paid when due at
any stated or accelerated maturity, the Borrower agrees to pay, in addition to
principal and interest, all costs of collection, including reasonable attorneys'
fees.

         This Note shall be governed by and construed in accordance with the
laws of the State of North Carolina.

                                   PHARMACEUTICAL PRODUCT DEVELOPMENT, INC.,
                                   a North Carolina corporation

                                   By:  /s/ Rudy C. Howard
                                   Name:    Rudy C. Howard
                                   Title:   Chief Financial Officer