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Exhibit 10(s)

     THIRD COMMERCIAL PROMISSORY NOTE MODIFICATION AGREEMENT

     THIS THIRD COMMERCIAL PROMISSORY NOTE MODIFICATION AGREEMENT
is made this 30th day of November, 1997, by and between
PHARMAKINETICS LABORATORIES, INC., a corporation organized under
the laws of the State of Maryland (the "Borrower") and
NATIONSBANK, N.A., formerly known as NATIONSBANK OF MARYLAND,
N.A., successor by mergers to MARYLAND NATIONAL BANK,  a national
banking association (the "Lender").

     WHEREAS, by that certain Commercial Promissory Note dated
May 13, 1993 (as amended, modified, restated, substituted,
extended and renewed at any time and from time to time, the
"Note") the Borrower became indebted to the Lender in an amount
not to exceed $500,000 (the "Revolving Credit Committed Amount")
under a revolving line of credit made by the Lender to the
Borrower pursuant to that certain Loan Agreement dated May 13,
1993 (as amended, modified, substituted, extended, and renewed
from time to time, the "Loan Agreement"); and 

     WHEREAS, the Note matures on the date hereof and the
Borrower and the Lender wish to provide for the extension of the
Note's maturity and the other changes as herein set forth.

     NOW, THEREFORE, THIS AGREEMENT WITNESSETH:

     That in consideration of the premises and other good and
valuable consideration, the receipt and sufficiency of which is
hereby acknowledged, the Lender and the Borrower covenant and
agree as follows:

     1.  The Borrower acknowledges that the present principal
balance of the Note is due and owing, subject to the terms of
repayment hereinafter set forth, without defense, recoupment,
counterclaim or offset.

     2.  The Borrower and Lender agree that the maturity date in
the Note is hereby changed November 30, 1997 to the November 30,
1998.

     3.  The terms, provisions and covenants of the Note are in
all other respects hereby ratified and confirmed and remain in
full force and effect.

     4.  It is expressly agreed that the indebtedness evidenced
by the Note has not been extinguished or discharged hereby.  The 


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Borrower and the Lender agree that the execution of this
Agreement is not intended to and shall not cause or result in a
novation with regard to the Note.

     WITNESS the signatures and seals of the Borrower and the
Lender the day and year first above written.

WITNESS or ATTEST:              PHARMAKINETICS LABORATORIES, INC.

/s/ Taryn L. Kunkel             By: /s/ James K. Leslie (SEAL)
-------------------                --------------------
                                   James K. Leslie
                                   President and 
                                   Chief Executive Officer

WITNESS:                        NATIONSBANK, N.A.

/s/ Taryn L. Kunkel             By: /s/ James W. Kirschner (SEAL)
-------------------                -----------------------
                                   James W. Kirschner
                                   Vice President

              GUARANTOR ACKNOWLEDGMENT AND AGREEMENT
  
     The undersigned respectively guaranteed to the Lender all of
the Obligations (as defined in the Loan Agreement), including
without limitation, the per annum rate of interest (as defined in
the annexed Third Commercial Promissory Note Modification
Agreement) and hereby covenants and agrees with the Lender that
the execution of the foregoing Third Commercial Promissory Note
Modification Agreement of even date herewith and the transactions
described therein and contemplated thereby do not and shall not
in any manner affect its obligations and liabilities under its
guaranty dated May 13, 1993 (the "Guaranty"), and that the
Guaranty is hereby ratified and confirmed and remains in full
force and effect.

     Dated effective as of this 30th day of November, 1997.

WITNESS:                   PKLB Limited Partnership
                           By:  PharmaKinetics Laboratories, Inc.
                                General Partner

/s/ Taryn L. Kunkel        By: /s/ James K. Leslie (SEAL)
-------------------           ---------------------
                              James K. Leslie
                              President and 
                              Chief Executive Officer

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