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                                                                     Exhibit 4.6

                               AMENDING AGREEMENT

          THIS AGREEMENT is made as of March 31, 2003

B E T W E E N:

          DRAXIS HEALTH INC., a corporation incorporated under the laws of
          Canada
          (hereinafter referred to as "Draxis")

                                     - and -

          ELAN PHARMA INTERNATIONAL LIMITED, a corporation incorporated under
          the laws of Ireland
          (hereinafter referred to as "Elan Pharma")

                                     - and -

          ELAN PHARMACEUTICALS, INC., a corporation incorporated under the laws
          of the State of Delaware
          (hereinafter referred to as "EPI" and hereinafter collectively with
          Elan Pharma referred to as "Elan").

Recitals:

A.   Draxis and Elan entered into a License, Distribution and Supply Agreement
     dated as of June 17, 1999 (the "License Agreement"), which provided Draxis
     with certain license and distribution rights with respect to the Products
     in the Territory on the conditions and terms contained in the License
     Agreement;

B.   Elan assigned certain rights and obligations with respect to Diastat(R) to
     Xcel Pharmaceuticals, Inc. pursuant to the Diastat Asset Purchase Agreement
     dated March 31, 2001 including without limitation, Elan's rights under the
     License Agreement as it relates to Diastat(R), as a result of which Draxis
     and Elan have no ongoing relationship regarding Diastat; and

C.   Subject to the terms and conditions set forth herein, Elan and Draxis
     desire to (i) terminate the License Agreement with respect to certain of
     the Products and (ii) amend the License Agreement with respect to certain
     of the Products.

For good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the parties agree as follows:

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1.   Defined Terms

     Capitalized terms used in this Amending Agreement and not otherwise defined
herein shall have the meanings ascribed thereto in the License Agreement.

2.   Products

     (a)  As of the date hereof, Section 1.17 of the License Agreement is hereby
          amended to state, in its entirety, as follows:

          "Product(s)" means any or all of the following products, to the extent
          of the rights owned, licensed or controlled by Elan in the Territory:
          Zanaflex(R) and Mysoline(R) and any Improvements to any of the
          Products which Elan owns or under which Elan is licensed with the
          right to sublicense in the Territory.

     (b)  As of the date hereof, Section 1.24 shall be added to the License
          Agreement and shall state, in its entirety, as follows:

          "Excluded Product(s)" means any or all of the following products,
          Neurobloc(TM) (botulinum toxin type B), frovatriptan, Zelapar(TM)
          (selegiline hydrochloride flashtab), Zonegran(TM) (zonisamide),
          Zanaflex(R) MR (tizanidine hydrochloride) and ziconotide, including,
          without limitation, any regulatorily-approved commercial brand names
          of the above noted products, such as Frovelan(R), MyoBloc(R) and
          Prialt(R).

     (c)  As of the date hereof, the only provisions of the License Agreement
          that shall apply to the Excluded Products are the following: Sections
          5, 6, 13.3, 14, 15.4 (only as to facts existing on or before the date
          hereof), 15.6, 16, 21.1, 23.1, 23.2, 23.4, 23.5, 23.6, 23.8 and 23.9.
          Sections 15.1, 15.3 and 15.7 shall continue to apply but only with
          respect to MyoBloc supplied by Draxis in Canada. Section 15.5 shall
          continue to apply to the Excluded Products but only with respect to
          the obligations of Draxis provided for therein and Elan shall have no
          further obligations thereunder.

     (d)  As of the date hereof, Attachment A is hereby amended to delete any
          references to any patents, patent applications or trademarks relating
          to the Excluded Products.

3.   Other Provisions

     (a)  As of the date hereof, the License Agreement is hereby amended to
          delete Sections 7.2, 7.6, 13.1, 13.2 and 20.2.

     (b)  Notwithstanding anything to the contrary in the License Agreement,
          including without limitation Article 7, the Project Committee shall
          consist of one representative from each party who will meet on an as
          needed basis to perform the functions of the Project Committee set out
          in the License Agreement, except to the extent such functions are
          amended hereby.

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     (c)  Notwithstanding anything to the contrary in the License Agreement, no
          further Performance Incentives are payable under the License
          Agreement.

4.   Consideration

     In consideration of the amendments to the License Agreement, Elan shall, on
the date hereof, pay U.S. $6,500,000 in immediately available funds to Draxis by
way of wire transfer. Neither party shall be required to pay the Termination Fee
in connection with this Amending Agreement or the transactions contemplated
hereby. Notwithstanding anything to the contrary in the License Agreement, as of
the date hereof, the Termination Fee shall not be applicable to any future
termination of the License Agreement.

5.   Transitional Support

     Elan shall be solely responsible and liable for taking all actions, paying
all fees to, and conducting all communication with, the appropriate governmental
or regulatory authority relating to any Excluded Product after the date hereof,
including preparing and filing all reports and submissions (and prosecuting such
submissions) with the appropriate governmental or regulatory authority; provided
that for one month from the date hereof Draxis will provide, at the reasonable
request of Elan, transitional support for the orderly transition of Canadian
regulatory issues. Elan shall reimburse Draxis for all out of pocket costs
incurred in providing such transitional support, including without limitation,
regulatory fees, disbursements and file transfer costs incurred with respect
thereto.

6.   Inventory

     Draxis shall return forthwith all Myobloc inventory in its possession and
Elan waives any amounts owing for outstanding invoices for Myobloc. Draxis
confirms that it holds no other inventory with respect to the Excluded Products.

7.   Return of Regulatory and Proprietary Information

     Draxis shall return to Elan as soon as reasonably possible after the date
hereof all relevant regulatory information and documents in Draxis' possession
and any other Elan Proprietary Information, related to the Excluded Products and
shall destroy all internal copies and backups thereof.

8.   Regulatory Support

     Each party acknowledges that for the purpose of specifying Elan's
regulatory support obligations pursuant to Section 7.4 and 7.5 of the License
Agreement, Elan shall without limitation assist Draxis in the following manner:

     (a)  Elan shall notify Draxis in advance regarding any contemplated
          formulation change to the Products and will continue to supply
          original formulated Products until Draxis has obtained approval from
          Health Canada for the new formulation or site manufacturing change.

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     (b)  Elan will cooperate fully with Draxis for all Health Canada related
          quality issues that may arise as well as any quality issues arising
          from non-compliance with standard operating procedures in the
          industry. On request, Elan shall provide all necessary documentation
          required by Draxis to perform all quality assurance functions as well
          as all quality control functions (these include, without limitation,
          certificates of analysis, method transfers, updated master and
          executed batch records, change controls and any other such documents).

     (c)  Elan will provide Draxis with all information that is reasonably
          necessary to carry out appropriate pharmacovigilance including,
          without limitation:

          -    safety reports (annual safety updates and/or PSURs) generated by
               the safety group at Elan; and

          -    provide within five (5) working days (or sooner should immediate
               action be required) any potential new safety signals that the
               Elan safety group detects in its operations.

     (d)  On request, Elan will provide Draxis with all necessary documents to
          meet its requirements to Health Canada and ensure patient safety.
          Specifically, Elan will provide:

          -    all changes made to the package insert (PI) or product monograph
               (PM);

          -    all anticipated changes to the PI must be communicated to Draxis
               prior to the final document sign-off at Elan so that Draxis can
               liaise in advance with Health Canada (this must be done (i) at
               least ten (10) working days prior to Elan sending the final
               document to the FDA or other regulatory body or (ii) in the event
               that the FDA or regulatory body provides Elan with less than ten
               (10) working days to finalize the PI as soon as reasonably
               possible); and

          -    all data and final reports pertaining to PM changes so that
               Draxis can make appropriate changes to its own PM in Canada.

     (e)  All plans for future modifications and development of TIZANIDINE
          should be shared expeditiously with Draxis including all final
          clinical study reports.

     (f)  Notwithstanding anything to the contrary provided for herein, in the
          event that Elan does not commercialize any Improvement it shall have
          no obligation to supply Draxis with Product containing such
          Improvement provided that Elan agrees to discuss in good faith
          potential Canadian commercialization of such Product without
          committing to supply Product.

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9.   Waiver of Certain Claims under the License Agreement

     Each party waives any claims as of the date hereof it may have against the
other for breach of contract or failure to perform under the terms of the
License Agreement including, without limitation, claims related to failure to
provide timely regulatory assistance and clinical information and breaches of
representations and warranties related to the status of the Patent Rights and
Elan's Cost of Goods and releases the other party, its affiliates and their
respective officers, directors and employees therefrom. Each party represents
and warrants that it has not brought any such claim or proceeding in any legal
or arbitration forum as of the date hereof, and that it has not assigned or
transferred any such claim to any other party. Notwithstanding the foregoing, ,
neither party waives any right to any rights to indemnification under the
License Agreement (a) related to third party claims in tort or contract arising
prior to the date hereof or (b) arising out of any obligations arising after the
date hereof relating to Zanaflex and Mysoline.

10.  Reaffirmation of the License Agreement

     Except as expressly amended by this Amending Agreement, the provisions of
the License Agreement remain in full force and effect.

11.  Further Assurances

     Each party must from time to time execute and deliver all such further
documents and instruments and do all acts and things as the other party may
reasonably require to effectively carry out or better evidence or perfect the
full intent and meaning of this Agreement.

12.  Benefit of the Agreement

     This Agreement will enure to the benefit of and be binding upon the
respective successors and permitted assigns of the parties hereto.

13.  Counterparts

     This Amending Agreement may be executed in any number of counterparts and
all of such counterparts taken together shall be deemed to constitute one and
the same instrument. Counterparts may be executed either in original or faxed
form and the Parties adopt any signatures received by a receiving fax machine as
original signatures of the Parties; provided, however, that any Party providing
its signature in such manner shall promptly forward to the other Party an
original of the signed copy of this Amending Agreement which was so faxed.

14.  Governing Law

     This Agreement will be governed by and construed in accordance with the
laws of the state of Delaware, without regard to its choice of law principles.

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     IN WITNESS WHEREOF the parties have executed this Agreement.

                                            DRAXIS HEALTH INC.

                                            Per:  /s/ Martin Barkin, M.D.
                                                 -------------------------------
                                                 Name:  Martin Barkin
                                                 Title: President


                                            ELAN PHARMA INTERNATIONAL LIMITED

                                            Per:  /s/ Kevin Insley
                                                 -------------------------------
                                                 Name:  Kevin Insley
                                                 Title: Authorized Signatory


                                            ELAN PHARMACEUTICALS, INC.

                                            Per:  /s/ David Hurley
                                                 -------------------------------
                                                 Name:  David Hurley
                                                 Title: Chief Financial Officer