SIXTH AMENDMENT TO
                       AMENDED AND RESTATED LOAN AGREEMENT


         This  Amendment  is  made as of June  7,  1999  by and  between  COPLEY
PHARMACEUTICAL,  INC., a Delaware  corporation  with its principal  office at 25
John Road, Canton,  Massachusetts (the "Borrower"),  and BANKBOSTON, N.A. (f/k/a
The First  National Bank of Boston),  a national  banking  association  with its
principal office at 100 Federal Street, Boston, Massachusetts (the "Bank").

                                 R E C I T A L S

         A. The Bank and the  Borrower  are  parties  to a certain  Amended  and
Restated  Loan  Agreement  dated August 17, 1993,  as amended by a certain First
Amendment to Amended and Restated Loan Agreement  dated June 29, 1995, a certain
Second Amendment to Amended and Restated Loan Agreement dated August 30, 1995, a
certain Third  Amendment to Amended and Restated Loan Agreement  dated March 25,
1996, a certain Fourth  Amendment to Amended and Restated Loan  Agreement  dated
July 31,  1996 and a certain  Fifth  Amendment  to  Amended  and  Restated  Loan
Agreement dated August 7, 1997 (as amended,  the "Loan Agreement").  Capitalized
terms used herein without  definition  have the meaning  assigned to them in the
Loan Agreement.

         B. The Borrower has requested certain  amendments to the Loan Agreement
as set forth herein.

         C.  Subject to  certain  terms and  conditions,  the Bank is willing to
agree to the same, as hereinafter set forth.

         NOW, THEREFORE,  for good and valuable  consideration,  the receipt and
sufficiency of which is hereby acknowledged, the parties agree as follows:

I.       AMENDMENTS TO LOAN AGREEMENT.

         The  Borrower  and the Bank  agree  that the  Loan  Agreement  shall be
amended as follows:

         1. Definition of Commitment.  The definition of "Commitment" in Section
1.1 of the Loan Agreement is hereby amended to read in its entirety as follows:

         "Commitment:  $25,000,000."

         2.  Definition of Maturity Date.  The definition of "Maturity  Date" in
Section 1.1 of the Loan  Agreement is hereby  amended to read in its entirety as
follows:

         "Maturity Date:  October 31, 2001."

         3. Deletion of Definitions.  The definitions of  "Consolidated  Current
Assets" and "Consolidated  Current  Liabilities" are deleted from Section 1.1 in
their entirety.

         4. Section 9.2.  Section 9.2 of the Loan Agreement is hereby deleted in
its entirety and replaced with the following:

         "ss.9.2  Profitability.  The Borrower and its  Subsidiaries  shall earn
         Consolidated  Net Income of at least $1,000 for each period of four (4)
         consecutive  fiscal  quarters ending December 31, March 31, June 30 and
         September 30."

         5. Exhibit A. Exhibit A to the Loan Agreement is hereby supplemented by
the Fourth Amendment to Amended and Restated  Promissory Note attached hereto as
Exhibit A.

II.      NO FURTHER AMENDMENTS.

         Except as specifically  amended herein, all terms and conditions of the
Loan Agreement shall remain in full force and effect as originally  constituted.
Each reference in the Loan Agreement to "this Agreement",  "hereunder", "hereof"
or words of like  import  referring  to the Loan  Agreement  shall mean and be a
reference  to the Loan  Agreement as amended by this Sixth  Amendment,  and each
reference  in any  other  Loan  Document  to the Loan  Agreement,  "thereunder",
"thereof" or words of like import referring to the Loan Agreement shall mean and
be a reference to the Loan Agreement as amended by this Sixth Amendment.

III.     CONDITIONS.

         The willingness of the Bank to agree to the foregoing is subject to the
following conditions:

         (A) The  Borrower  shall have  executed  and  delivered to the Bank (or
shall have caused to be executed and  delivered  to the Bank by the  appropriate
persons) the following:

                  (i)      This Sixth Amendment;

                  (ii) A Fourth  Amendment  to Amended and  Restated  Promissory
Note, in the form of Exhibit A hereto;

                  (iii)    True and complete  copies of any required  directors'
                           consents and/or resolutions authorizing the execution
                           and delivery of this Sixth  Amendment  and the Fourth
                           Amendment to Amended and Restated Promissory Note and
                           other documentation referred to herein,  certified by
                           the Secretary of the Borrower; and

                  (iv)     Such other  supporting  documents and certificates as
                           the Bank or its counsel may reasonably request.

         (B) All legal matters incident to the transactions  contemplated hereby
shall be satisfactory to counsel for the Bank.

IV.      MISCELLANEOUS.

         1. The Borrower  represents  and warrants that no event has occurred or
failed to occur, which constitutes, or which, solely with the passage of time or
the giving of notice (or both) would constitute, an Event of Default.

         2. The  execution  and delivery of this Sixth  Amendment and the Fourth
Amendment to Amended and Restated  Promissory Note by the Borrower has been duly
authorized  by all  requisite  corporate  action  of the  Borrower  and will not
violate  any  provision  of law,  any order,  judgment or decree of any court or
other agency of government,  or the organizational  documents of the Borrower or
any other  instrument to which the Borrower is a party, or by which the Borrower
is bound.  This Sixth Amendment and the Fourth Amendment to Amended and Restated
Promissory  Note  constitute  the legal,  valid and binding  obligations  of the
Borrower,  enforceable  against the Borrower in accordance with their respective
terms.

         3. The  representations  and  warranties  contained in Section 6 of the
Loan  Agreement  are true and correct in all material  respects on and as of the
date of this Sixth  Amendment  as though made on and as of such date  (except to
the extent  that such  representations  and  warranties  expressly  relate to an
earlier  date or  except  to the  extent  variations  therefrom  have  been  (i)
permitted under the terms of Loan Agreement,  (ii) otherwise approved in writing
by the  Bank or (iii)  reflected  in  reports  filed  by the  Borrower  with the
Securities and Exchange Commission).

         4. As provided in the Loan Agreement,  the Borrower agrees to reimburse
the Bank upon demand for all out-of-pocket costs,  charges,  liabilities,  taxes
and expenses of the Bank (including reasonable fees and disbursements of counsel
to the Bank) in connection with the  preparation,  negotiation,  interpretation,
execution  and  delivery  of this  Sixth  Amendment  and any  other  agreements,
instruments or documents executed pursuant or relating hereto.

         5. The Borrower represents,  warrants, and agrees that the Borrower has
no claims,  defenses,  counterclaims  or offsets  against the Bank in connection
with the Loan  Agreement  or the  Obligations,  and, to the extent that any such
claim,   defense,   counterclaim  or  offset  may  exist,  the  Borrower  hereby
affirmatively WAIVES AND RELEASES Bank from the same.

         6. This Sixth  Amendment may be executed in any number of  counterparts
and by different parties hereto on separate counterparts,  each of which when so
executed and delivered shall be an original, but all of which counterparts taken
together shall be deemed to constitute one and the same agreement.

         7. This Sixth Amendment shall take effect as a sealed  instrument under
the  laws of the  Commonwealth  of  Massachusetts  as of the  date  first  above
written.

                                           COPLEY PHARMACEUTICAL, INC.


                                           By: /s/ Daniel M.P. Caron
                                               -----------------------
                                                Daniel M.P. Caron, CFO

                                           BANKBOSTON, N.A.


                                           By:  /s/ Jeffrey R. Westling
                                                -----------------------
                                                 Jeffrey R. Westling, Director