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                                                                    EXHIBIT 4.12

                            Toronto Technology Group

NATIONAL
BANK
OF CANADA

                                                                  March 28, 2002


Draxis Pharma Inc.
6870 Goreway Drive
Mississauga, ON  L4V 1P1

Attention: Mr. Jim A.H. Garner
           Senior Vice President, Finance & CFO

Dear Mr. Garner

                       Amendment to Credit Facilities for
                               Draxis Pharma Inc.

                                   ----------

     We refer to the credit agreement (the "Credit Agreement") entered into
between National Bank of Canada (the "Bank") and Draxis Pharma Inc. (the
"Borrower") pursuant to an offer of financing from the Bank to the Borrower
dated June 9, 1998 and accepted by the Borrower on June 12, 1998, as amended by
a letter agreement dated February 16, 2000 (release of guarantee), by an
amendment dated February 18, 2000 (investment by SGF Sante Inc. ("SGF")) and by
a letter agreement dated June 12, 2001. Capitalized terms used herein and not
otherwise defined shall have the meaning ascribed thereto in the Credit
Agreement, and specifically in Schedule A annexed to the offer of financing.

     The Borrower is proposing to establish certain credit facilities with each
of Investissement Quebec ("IQ") on the one hand and Draxis Health Inc. ("DHI")
and SGF on the other hand and to grant security to each of IQ, DHI and SGF for
its obligations under such credit facilities, all as more particularly described
in Schedule A attached hereto. The Borrower has requested the consent of the
Bank to the creation of the hypothecs in favour of IQ and in favour of each of
DHI and SGF. The Borrower has also requested that the Bank waive, for a period
of 12 months, the obligation of the Borrower to make monthly payments of
principal to the Bank under the Credit Agreement. The Borrower has also
requested the consent of the Bank to the

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making of loans in the aggregate amount of $21,710.80 by the Borrower to
Mohammed Barkat for purposes of subscription by Mohammed Barkat for 18,092
common shares of the Borrower, such loan not to exceed 80% of the subscription
price of such shares in accordance with the Equity Participation Plan of the
Borrower dated February 18, 2000. In consideration of the Bank agreeing to
provide such consent and waiver, the Bank and the Borrower hereby agree to amend
the Credit Agreement as follows:

1.   REPAYMENT OF PRINCIPAL. Section 6 of the Credit Agreement is hereby amended
to provide that during the 12 month period commencing on March 27, 2002 and
ending on February 26, 2003, unless a default has occurred under the Credit
Agreement, the Borrower shall not be required to pay any amount on account of
principal of the loan. The Borrower shall continue to be obliged to make
payments of interest on the outstanding principal amount of the loan on the 26th
day of April, 2002 and on the 26th day of each following month up to and
including the 26th day March, 2003. Thereafter, the amount of principal of the
loan shall be repaid in equal and consecutive monthly instalments of principal,
commencing on the 26th day of April, 2003 and thereafter on the 26th day of each
following month, in the amount necessary to result in the repayment in full of
all principal amounts on August 26, 2008. The balance of principal, interest,
fees, accessories and all other sums that may be due to the Bank shall be repaid
in full on August 26, 2008, without further notice.

2.   FLOATING RATE. The term loan shall bear interest at the Canadian Prime Rate
of the Bank plus 1.00%. Section 4.1 of the Credit Agreement is hereby amended by
deleting the reference to "Canadian Prime Rate of the Bank plus 0.75%" and
substituting therefor "the Canadian Prime Rate of the Bank plus 1.00%" effective
from and including the date hereof.

3.   STANDBY FEES. Section 4.3 of the Credit Agreement is hereby amended by
adding the following provision with respect to the operating facility effective
from and including the date hereof:

     "Standby fees of 0.25% per annum on the average daily unused operating
     facility available to the Borrower are payable monthly, in arrears, on the
     26th day of each month."

4.   SECURITY.

     (a) The Bank hereby consents to the Borrower granting a first ranking
hypothec in the equipment financed by IQ and described in Schedule A annexed
hereto (or which may be described in writing upon quarterly disbursements by IQ
provided that the equipment subsequently described is either the LYO Unit or
Project Equipment, as defined in the Intercreditors' Agreement referred to
herein), (the "Equipment") to IQ and a second ranking hypothec on all other
moveable and immoveable property of the Borrower in favour of IQ (the "IQ
Security") and a third ranking hypothec in all moveable and immoveable property
of the Borrower in favour of each of DHI and SGF (collectively, the "DHI/SGF
Security") provided that such DHI/SGF Security is fully subordinated to the
hypothecs and security interests of the


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Bank in the moveable and immoveable property of the Borrower (the "Bank
Security") and that the obligations of the Borrower to each of DHI and SGF are
fully subordinated and, following the occurrence of an event of default under
the Credit Agreement, postponed to the obligations of the Borrower to the Bank
under the Credit Agreement and the Bank Security and to the obligations of the
Borrower to IQ and the IQ Security and that the provisions for payment by the
Borrower to DHI and SGF are otherwise on terms satisfactory to the Bank, the
whole as more fully set out in the InterCreditors' Agreement (the
"Intercreditors' Agreement") to be entered into on the date hereof by the Bank,
IQ, DHI, SGF and the Borrower as it may be amended from time to time.

     (b) The Borrower hereby confirms that the security granted by the Borrower
to the Bank pursuant to section 8 of the Credit Agreement extends to and
includes all new equipment to be acquired by the Borrower and shall rank prior
to the IQ Security and the DHI/SGF Security except for the prior ranking
security interest of IQ in the Equipment to be acquired by the Borrower with the
financing from IQ.

     (c) The priorities, rights and obligations of the Bank, IQ, DHI and SGF
with respect to the Bank Security, the IQ Security and the DHI/SGF Security
shall be set forth in the Intercreditors' Agreement which shall be in form and
on terms satisfactory to the Bank.

5.   EVENTS OF DEFAULT. Section 13.1 of the Credit Agreement is amended by
adding the following as section 13.1.11:

     "If the Borrower or Draxis Health Inc. is in default under any of the terms
     and conditions of any of the agreements or documents relating to the
     financing to be provided to the Borrower by IQ or SGF, including, without
     limitation, the IQ Security, the DHI/SGF Security and the Intercreditors'
     Agreement."

6.   POSITIVE COVENANTS. Section 11.1.4 of the Credit Agreement is hereby
amended to provide as follows:

     "11.1.4. Maintain, at all times prior to December 31, 2002, a Debt Ratio
     not exceeding 1.6:1.0 and maintain, at all times after December 31, 2002, a
     Debt Ratio not exceeding 1.0:1.0."

7.   NEGATIVE COVENANTS. Section 11.2 of the Credit Agreement is hereby amended
by adding the following section:

     "11.2.7. Make any repayment under any of the Subordinated Loan Documents
     (as defined in the Intercreditors' Agreement) or otherwise make any
     distributions to any of the shareholders of the Borrower in an amount in
     excess of 50% of Free Cash Flow."

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8.   DEFINITIONS. Section 14.1 of the Credit Agreement is hereby amended by
adding the following definitions:

     "FREE CASH FLOW" means, for any fiscal period, (i) EBITDA for such period,
     less (ii) an amount equal to any increase in working capital for such
     period or plus an amount equal to any decrease in working capital for such
     period, as the case may be, less (iii) any capital expenditures made during
     such period other than capital expenditures provided for in the capital and
     financing plan of the Borrower ratified by the Borrower on March 28, 2002
     and delivered to the Bank and in respect of which such plan provides for
     funding of such capital expenditures from the proceeds of financing from
     IQ, DHI and SGF or additional equity contributions, less (iv) an amount
     equal to any payments of principal or interest made, or required to be
     made, during such period on account of indebtedness of the Borrower to the
     Bank or IQ, and less (v) an amount equal to any payment made by the
     Borrower on account of Large Corporation Tax.

     "EBITDA" means the net income (or, as the case may be, net loss) of the
     Borrower and its consolidated Subsidiaries determined in accordance with
     GAAP (but excluding extraordinary items) increased by the sum of, without
     duplication (i) the total of all items properly classified as interest
     expense in accordance with GAAP, (ii) the aggregate of all taxes (including
     future income taxes) based on the net income of the Borrower and its
     consolidated Subsidiaries for such period determined in accordance with
     GAAP; and (iii) the aggregate of all depreciation, amortization and other
     like reductions to income of the Borrower and its consolidated Subsidiaries
     not involving or requiring an outlay of cash for such period determined in
     accordance with GAAP.

     "GAAP" means accounting principles generally accepted by the Canada
     Institute of Chartered Accountants, consistently applied.

9.   CONDITIONS PRECEDENT. The effectiveness of this Amending Agreement and the
consents granted by the Bank herein shall be subject to the following conditions
being satisfied to the satisfaction of the Bank:

     (a)  the Borrower shall be in compliance with all of its covenants and
          obligations under the Credit Agreement and no default shall have
          occurred under the Credit Agreement both immediately prior to giving
          effect of the IQ, DHI and SGF financings and immediately after giving
          effect thereto and that each of its


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          representations and warranties in the Credit Agreement is true in all
          material respects on the date of this Amending Agreement after giving
          effect to the IQ, DHI and SGF financings and the Borrower shall
          deliver a certificate of a senior officer of the Borrower to the Bank
          to such effect and confirming that the incorporating documents and
          by-laws of the Borrower previously delivered to the Bank have not been
          amended or, if amending, annexing copies of all amendments;

     (b)  the Borrower shall deliver to the Bank a duly certified copy of the
          resolution of the board of directors of the Borrower establishing the
          Borrower's authority to execute this Amending Agreement and the IQ,
          DHI and SGF financing agreements and to perform its obligations
          hereunder and thereunder;

     (c)  the Borrower shall deliver to the Bank certificates of incumbency;

     (d)  a certified copy of all documents and agreements pertaining to the IQ
          financing and the DHI and SGF financings shall have been delivered to
          the Bank;

     (e)  the Borrower shall have delivered to the Bank evidence satisfactory to
          the Bank that DHI and SGF have entered into binding agreements to
          contribute by way of equity investment in the Borrower an additional
          aggregate amount of $6,286,000, with not less than $1,286,000 of such
          amount having been contributed on or before closing and the balance to
          be contributed to the Borrower on the earlier of (i) May 31, 2002 and
          (ii) the date on which an aggregate of $5,000,000 of payments becomes
          due by the Borrower with respect to capital expenditures contracted
          for after January 1, 2002 pursuant to the capital and financing plan
          of the Borrower ratified by the Borrower on March 28, 2002 and
          delivered to the Bank;

     (f)  IQ, DHI, SGF and the Borrower shall have entered into the
          Intercreditors' Agreement in form and on terms satisfactory to the
          Bank;

     (g)  the Borrower shall have delivered to the Bank satisfactory legal
          opinions with respect to this Amending Agreement and the
          Intercreditors' Agreement, the Bank Security, the IQ Security and the
          DHI/SGF Security and such other matters relating to the financings
          from IQ, DHI and SGF as the Bank may reasonably request; and

     (h)  the Borrower shall have paid to the Bank an annual review and
          amendment fee in the amount of $50,000.

10.  PAYMENT OF EXPENSES. The Borrower shall pay all reasonable out-of-pocket
expenses of the Bank incurred in the preparation, negotiation, execution and
delivery of this


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Amending Agreement and all documents relating hereto, including, without
limitation, the Intercreditors' Agreement.

11.  GOVERNING LAW. This amending agreement shall be governed by and
construed in accordance with the laws of the province of Quebec and the
federal laws of Canada applicable therein.

12.  COUNTERPARTS. This amending agreement maybe executed in any number of
counterparts, in each of which so executed shall be deemed to be an original,
and all such counterparts taken together shall be deemed to constitute one in
the same instrument.

13. LANGUAGE (QUEBEC). The parties declare that they have requested and do
hereby confirm their request that the present agreement and the ancillary
documents related thereto be in English; les parties declarent qu'elles ont
exige et par les presentes confirment leur demande que la presente convention
ainsi que les documents connexes soient rediges en anglais.



                                   Yours truly,

                                   NATIONAL BANK OF CANADA

                                   Per:  /s/ Kevan Churchman
                                         --------------------------------------
                                         Kevan Churchman
                                         Senior Account Manager

                                   Per:  /s/ David Robinson
                                         --------------------------------------
                                         David Robinson
                                         Senior Manager, Technology Group

                                   Accepted and Agreed this 28th day of
                                   March, 2002

                                   DRAXIS PHARMA INC.

                                   Per:  /s/ Douglas Parker
                                         --------------------------------------

                                   Per:     /s/ Jim A.H. Garner
                                         --------------------------------------