AMENDMENT NO. 1 TO
                          INVESTMENT BANKING AGREEMENT


         This Amendment No. 1 to Investment Banking Agreement is made as of this
23rd day of September,  1996 by and between DynaGen,  Inc.,  having its business
offices at 99 Erie Street, Cambridge, MA 02139 (the "Company") and H.J. Meyers &
Co., Inc., having its business offices at 1895 Mt. Hope Avenue,  Rochester,  New
York 14620 (the "Consultant").

         WHEREAS, the Company and the Consultant have entered into an Investment
Banking Agreement dated November 20, 1995 (the "Agreement"); and

         WHEREAS,  the parties  desire to supplement  and amend the Agreement as
set forth below.

         NOW,  THEREFORE,  in  consideration  of the  foregoing  and the  mutual
promises and covenants contained herein, it is agreed as follows:

         1.  Paragraph 1 is hereby deleted and replaced in its entirety with the
following:

                  "1.  RETENTION.  The Company  hereby retains the Consultant to
perform non-exclusive consulting services related to corporate finance and other
matters,  and the Consultant  hereby accepts such retention and shall  undertake
reasonable  efforts to perform for the Company the duties described  herein.  In
this regard,  subject to paragraph 7 hereof,  the  Consultant  shall devote such
time and attention to the business of the Company, as shall be determined by the
Consultant, in its sole discretion,  subject to the direction of the Chairman of
the Company.

                       a)  The  Consultant  agrees,  to  the  extent  reasonably
required in the conduct of the  business of the  Company,  and at the  Company's
request, to place at the disposal of the Company its judgment and experience and
to provide business development services to the Company including the following:

                            (i) review the  Company's  managerial  and financial
requirements;

                            (ii) review budgets and business plans;

                            (iii)  analyze  and  assess   alternatives  for  the
Company,  presented  by the  Company for raising  capital,  including  public or
private offerings of the Company's securities; and

                            (iv) prepare and  disseminate a "Corporate  Profile"
report in compliance with applicable state and federal securities laws.




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                       b) In  addition,  the  Consultant  agrees,  to the extent
reasonably  required in the conduct of the business of the  Company,  and at the
Company's  request,  to place at the  disposal of the Company its  judgment  and
experience  and to provide a broad array of merger and  acquisition  services as
requested by the Company including:

                            (i)  identifying  opportunities  for  a  transaction
involving  the Company  including,  without  limitation,  the  purchasing by the
Company of other companies,  or any of their businesses,  assets, or properties,
or the sale of the Company, or any of its businesses, assets or properties, more
specifically,  in connection with the Company's acquisition of certain assets of
Able Laboratories, Inc.

                            (ii)   advising   the   Company    concerning   such
transactions with respect to structure;

                            (iii) providing detailed valuation analyses for such
transactions including formal fairness opinions if required.

                       c) At the Consultant's  request, the Company will provide
"due diligence"  presentations to Registered  Representatives  of the Consultant
and other brokerage firms."

         2.  Paragraph  3(a) of the Agreement is hereby  deleted and replaced in
its entirety with the following:

                  "3.  Compensation.

                       a) The  Consultant  shall be paid the sum of  $500,000.00
payable  upon the signing of this  Agreement.  In addition,  for its  consulting
services  hereunder,  the Company  shall grant to the  Consultant a warrant (the
"Warrant")  to purchase  400,000  shares of the Common Stock of the Company (the
"Registerable  Shares") exercisable for five (5) years from the date hereof at a
price of $2.50 per share.  Registerable  Shares  will not  include any shares of
Common Stock which are  eligible for sale  pursuant to Rule 144, as so opined by
the  Company's  outside  legal  counsel.  The  Warrant  shall be in a form to be
mutually agreed upon by the parties. All compensation is non-refundable."

         3. All other terms and provisions of the Agreement shall remain in full
force and effect.





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         IN WITNESS WHEREOF, the parties hereto have executed this Agreement the
day and year first above written.

         DYNAGEN, INC.


         By: /s/ Dhananjay G. Wadekar
            -------------------------- 

         Title: Chairman and Executive V.P.
               -----------------------------

         H.J. MEYERS & CO., INC.


         /s/ Michael S. Smith
         ------------------------------------
         Michael S. Smith
         Managing Director, Corporate Finance