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                                                                   Exhibit 10.4

                              TECHNOLOGY AGREEMENT


                  TECHNOLOGY AGREEMENT, dated as of March 20, 2002 (this
"AGREEMENT"), by and between HEXAL A.G., a German company ("HEXAL"), and EON
LABS, INC., a Delaware corporation ("EON").

                              W I T N E S S E T H :

                  WHEREAS, Hexal and its Affiliates are the exclusive owners
of the entire right, title and interest in and with respect to the
development, manufacture and sale in the United States of all of the
Information, Generic Products and Technology; and

                  WHEREAS, Hexal desires to grant Eon certain rights with
respect to the Information, Generic Products and Technology.

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

                                   ARTICLE I.

                           PARTNERSHIP AND COOPERATION

         Section 1.1. COOPERATION. Hexal hereby agrees to cooperate fully
with Eon with respect to the development, manufacture, and sale of any
Generic Products by Eon in the United States.

         Section 1.2. SHARING OF INFORMATION.

         (a)      At Eon's request for Information with respect to any
Generic Product, Hexal shall use its reasonable best efforts to furnish the
Information with respect to such Generic Product to Eon within a reasonable
amount of time following such request.

         (b)      Upon receipt of any requested Information with respect to a
Generic Product, Eon shall deliver to Hexal the applicable purchase price for
such Information, determined as follows:

                  (i)      IMMEDIATE RELEASE PRODUCT. The purchase price for the
                           Complete File for an Immediate Release Product shall
                           be $100,000.

                  (ii)     SUSTAINED RELEASE PRODUCT. The purchase price for the
                           Complete File for a Sustained Release Product shall
                           be $150,000.

                  (iii)    SPECIAL TECHNOLOGY PRODUCT. The purchase price for
                           the Complete File for a Special Technology Product
                           shall be the fair and reasonable market value of such
                           Complete File as mutually agreed upon in good faith
                           by Hexal and Eon.

                  (iv)     ADDITIONAL INFORMATION. The purchase price for any
                           Information other than a Complete File for any
                           Generic Product shall be the fair and

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                           reasonable market value of such Information as
                           mutually agreed upon in good faith by Hexal and Eon.

         Section 1.3. SPECIAL TECHNOLOGY PRODUCTS.

         (a)      At Eon's request, with respect to any Special Technology
Product, Hexal shall offer to (i) sell the Technology solely related to such
Special Technology Product to Eon or (ii) grant Eon an exclusive license to
the Technology solely related to such Special Technology Product in the
United States.

         (b)      As mutually agreed upon in good faith Hexal shall offer to
sell the Finished Special Technology Product to Eon for sale and distribution
in the United States; provided, however, that the sale of a Finished Special
Technology Product to Eon shall be determined on a case by case basis.

         (c)      The purchase price for such Technology (related to the
Special Technology Products), exclusive license and/or Finished Special
Technology Product shall be the fair and reasonable market value of
Technology, exclusive license and/or Finished Special Technology Product, as
applicable, as mutually agreed upon in good faith by Hexal and Eon.

         Section 1.4. VALUE ADDED PRODUCTS. Eon has no right to request any
information, technology or know-how from Hexal or its Affiliates related to
the Value Added Products. Notwithstanding, Hexal and Eon may cooperate with
respect to the Value Added Products so long as such cooperation has been
mutually agreed upon in good faith on a case by case basis by Hexal and Eon.
If Hexal and Eon agree to cooperate with respect to any of the Value Added
Products, such cooperation will be pursuant to separate agreements entered
into between Hexal and Eon.

                                   ARTICLE II.

                             RIGHT OF FIRST REFUSAL

                  Hexal shall not (i) transfer any of its right, title and
interest in and with respect to a Generic Product, or any Information or
Technology for such Generic Product, in the United States or (ii) grant any
licenses, exclusively or otherwise, for a Generic Product, or for any
Information or Technology for such Generic Product in the United States, to
any Person other than Eon, unless Hexal shall have first made an exclusive
offer with respect to such Generic Product, or related Information or
Technology, as applicable, to Eon. If Eon does not accept such exclusive
offer within sixty (60) days, Hexal is free to grant rights in such specific
Generic Product to any other party.

                                  ARTICLE III.

                                      TERM

                  The term of this Agreement (the "Term") shall be the period
commencing on March 20, 2002 and ending on March 19, 2007.

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                                   ARTICLE IV.

                                   TERMINATION

         Section 4.1. This Agreement may be terminated prior to the
expiration of the Term (a) by the mutual written consent of Hexal and Eon or
(b) by Hexal if Hexal and its Affiliates and Santo Holding (Deutschland)
GmbH, a German company, and its Affiliates, beneficially own (within the
meaning of Rule 13d-3 under the Securities Exchange Act of 1934, as amended)
less than fifty percent (50%) of the outstanding Common Stock, par value
$0.01 per share, of Eon, on a fully diluted basis; provided, however, that if
Hexal terminates this Agreement pursuant to subsection (b), Hexal agrees that
it shall negotiate in good faith with Eon to enter into a new agreement with
respect to the sharing of Generic Products, Information and Technology.

         Section 4.2. Upon the termination of any provision of this
Agreement, the restrictions and obligations set forth herein shall terminate
and be of no further effect, except that such termination shall not affect
rights perfected or obligations incurred under this Agreement prior to such
termination.

                                   ARTICLE V.

                        INTERPRETATION OF THIS AGREEMENT

         Section 5.1. TERMS DEFINED. As used in this Agreement, the following
terms have the respective meaning set forth below:

                  AFFILIATE: with respect to any Person, shall mean any
Person or entity, directly or indirectly controlling, controlled by or under
common control with such Person.

                  COMPLETE FILE: with respect to any Generic Product, shall
mean the formulation, the validated analytical and manufacturing procedures
as promulgated and, if available at Hexal, the biostudy related to such
Generic Product.

                  FINISHED SPECIAL TECHNOLOGY PRODUCT: shall mean a fully
manufactured Special Technology Product.

                  GENERIC PRODUCT: shall mean all strengths of a dosage form
for any pharmaceutical product which is developed and marketed by Hexal or
any of its German subsidiaries on or prior to the date hereof or developed
and marketed by Hexal or any of its German subsidiaries during the Term, in
each case for which (a) an Abbreviated New Drug Application would have to be
approved by the United States Food and Drug Administration prior to the sale
of such pharmaceutical product in the United States, (b) no clinical study is
required, and (c) Hexal has the right to enter into an agreement with Eon for
such product in the United States, its territories and possessions.

                  IMMEDIATE RELEASE PRODUCT: shall mean any Generic Product
utilizing immediate release delivery technology, other than Generic Products
which Eon is not capable of manufacturing without technology or know-how that
are proprietary to Hexal or its Affiliates.

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                  INFORMATION: with respect to any Generic Product, shall
mean the Complete File, or any portion thereof, for such Generic Product, and
any other information in the possession of Hexal and any of its German
subsidiaries regarding the formulation, manufacture and sale of such Generic
Product, including, but not limited to, any information regarding Technology.

                  PERSON: shall mean an individual, partnership, joint-stock
company, corporation, limited liability company, trust or unincorporated
organization, and a government or agency or political subdivision thereof.

                  SPECIAL TECHNOLOGY PRODUCT: shall mean any Generic Product
which Eon is not capable of manufacturing without technology or know-how that
are proprietary to Hexal or its Affiliates.

                  SUSTAINED RELEASE PRODUCT: shall mean any Generic Product
utilizing sustained release delivery technology, other than Generic Products
which Eon is not capable of manufacturing without technology or know-how that
are proprietary to Hexal or its Affiliates.

                  TECHNOLOGY: shall mean all rights with respect to any
technology, formulations, regulatory dossiers, technical information,
manufacturing processes and know-how to the extent related to the Generic
Products.

                  VALUE ADDED PRODUCT: shall mean any pharmaceutical product
that is not a Generic Product for which Hexal has the right to enter into an
agreement with Eon in the United States, its territories and possessions,
including any pharmaceutical product for which (a) Hexal can obtain a
World-Wide-License, (b) Hexal and/or its Affiliates have licensed in and /or
(c) Hexal and/or its Affiliates are developing for third parties.

                  WORLD-WIDE-LICENSE: shall mean a license covering the major
pharmaceutical markets, but which need not include Japan.

         Section 5.2. GOVERNING LAW. This Agreement shall be governed by and
construed in accordance with the laws of German applicable to contracts made
and to be performed entirely within such State. Jurisdiction for disputes
brought under this Agreement shall be Landgericht Muenchen II.

         Section 5.3. SECTION HEADINGS. The headings of the sections and
subsections of this Agreement are inserted for convenience only and shall not
be deemed to constitute a part thereof.

                                   ARTICLE VI.

                               FURTHER ASSURANCES

                  Hexal, for itself and its successors and assigns, hereby
agrees with Eon, its successors and assigns, that Hexal will do, execute and
deliver or will cause to be done, executed and delivered all such further
acts, transfers, assignments and conveyances, powers of attorney and
assurances, and will take all such further action, in order to confirm the
transfer or exclusive license of the Information and/or Technology to Eon,
its successors and assigns, all as Eon, its successors and assigns, shall
reasonably request.

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                                  ARTICLE VII.

                             RELATIONSHIP OF PARTIES

                  Neither of the parties shall act or represent or hold
itself out as having authority to act as an agent or partner of the other
party, or in any way bind or commit the other party to any obligations.
Nothing contained herein, whether express or implied, shall be construed as
creating a partnership, joint venture, agency, trust or other association of
any kind, or creating any of the rights or obligations of partners, joint
venturers or agents between or among the parties hereto.

                                  ARTICLE VIII.

                                PRIOR AGREEMENTS

                  The parties hereto acknowledge that this Agreement
supercedes the Assignment and Transfer of Products and Technology, dated as
of September 25, 1995 from and by Hexal Pharmaceuticals, Inc. to and with Eon.

                                   ARTICLE IX.

                                  MISCELLANEOUS

         Section 9.1.  NOTICES.

         (a)      All communications under this Agreement shall be in writing
and shall be delivered by hand or facsimile or mailed by overnight courier or
by registered or certified mail, postage prepaid:

                  (i)      if to Hexal, at Hexal AG, Industriestrasse 25, 83607
                           Holzkirchen, Germany, marked for the attention of Dr.
                           Thomas Strungmann, facsimile +49 8024 908 116, or at
                           such other address as Hexal may have furnished Eon in
                           writing; and;

                  (ii)     if to Eon, at 227-15 North Conduit Avenue, Laurelton,
                           New York, 11413, marked for the attention of
                           President, (facsimile: (718) 276-1735), or at such
                           other address as Eon may have furnished Hexal in
                           writing.

         (b)      Any notice so addressed shall be deemed to be given: if
delivered by hand or facsimile, on the date of such delivery; if mailed by
courier, on the first business day following the date of such mailing; and if
mailed by registered or certified mail, on the third business day after the
date of such mailing, except in the case of common proof of late arrival of
such notice.

         Section 9.2. SUCCESSORS AND ASSIGNS. This Agreement shall inure to
the benefit of and be binding upon the successors and assigns of each of the
parties.

         Section 9.3. ENTIRE AGREEMENT; AMENDMENT AND WAIVER. This Agreement
constitutes the entire understanding of the parties hereto relating to the
subject matter hereof and supersedes all prior understandings among such
parties. This Agreement may be amended, and the observance

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of any term of this Agreement may be waived, with (and only with) the written
consent of each of Hexal and Eon.

         Section 9.4. SEVERABILITY. In the event that any part or parts of
this Agreement shall be held illegal or unenforceable by any court or
administrative body of competent jurisdiction or otherwise by Law, such
determination shall not effect the remaining provisions of this Agreement
which shall remain in full force and effect.

         Section 9.5. COUNTERPARTS. This Agreement may be executed in one or
more counterparts, each of which shall be deemed an original and all of which
together shall be considered one and the same agreement.

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                  IN WITNESS WHEREOF, Hexal and Eon have caused this
Technology Agreement to be duly executed and delivered as of the date first
above written.

                              HEXAL A.G.


                              By: /s/ Thomas Strungmann
                                 -----------------------------------------------
                                   Name:  Thomas Strungmann
                                   Title: Co-President and Co-Chief Executive
                                          Officer


                              EON LABS, INC.


                              By: /s/ Bernhard Hampl, Ph.D.
                                 -----------------------------------------------
                                   Name:  Bernhard Hampl, Ph.D.
                                   Title: President and Chief Executive Officer

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