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                                                                   Exhibit 10.10

January 27, 2000

Mr. E. Thomas Arington
Chairman and CEO
Duramed Pharmaceuticals, Inc.
5040 Duramed Drive
Cincinnati, Ohio 45213

Dear Tom:

This letter will confirm our agreement, further details of which may be
elaborated in a subsequent agreement or agreements, regarding (i) the loan
guarantee to be provided by Solvay Pharmaceuticals, Inc. to Merrill Lynch
Business Financial Services, Inc. and (ii) the extended and enhanced alliance
with respect to the co-promotion of Cenestin(R). Such agreement(s) shall contain
the following provisions:

         1.       The Cenestin co-promotion agreement shall have a term of 10
                  years.

         2.       Effective January 1, 2000, Solvay Pharmaceuticals will be
                  responsible for and pay the advertising and sales promotion
                  ("ASP") and agreed-upon expenses related to Cenestin,
                  including direct selling expenses of Cardinal Market Force.

         3.       Upon completion of the "Investment Recovery Phase" (as defined
                  below), the parties shall share equally in the gross profits
                  from the sales of Cenestin, less ASP expenses incurred by
                  Solvay Pharmaceuticals, as illustrated in the financial models
                  [previously presented]. Investment Recovery Phase shall mean
                  the period of time from 1/1/2000 until the cumulative gross
                  profit from Cenestin sales exceeds the total of the Solvay
                  Pharmaceuticals Investment (defined as the cumulative ASP
                  incurred by Solvay Pharmaceuticals from 1/1/2000 forward) and
                  the Duramed 1999 Cenestin Investment (defined as $38,000,000).
                  During the Investment Recovery Phase, the split of gross
                  profits shall be calculated as follows:

Step 1 Investment Recovery Phase:
--------------------------------

THE BASIC FORMULA
--------------------------------------------------------------------------------

DRMD                             100%      Sales
DRMD                              15%      Cost of product @ standard
Gross profit                      85%      Gross profit (GP)

Solvay Pharmaceuticals gets       80%      of GP to cover ASP from 1-1-2000 and
                                           forward

DRMD gets                         20%      of GP

Step 2 Investment Recovery Phase:
--------------------------------

When Solvay Pharmaceuticals has recovered all of the on-going ASP costs CENESTIN
will be generating a profit. DRMD will receive 80% of the remaining gross profit
until they have recovered the specified "investments" (38 MUSD).
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THE BASIC FORMULA
--------------------------------------------------------------------------------
Step 1

DRMD                             100%      Sales
DRMD                              15%      Cost of Product @ standard
Gross profit                      85%      Gross profit (GP)

Solvay Pharmaceuticals gets       80%      of GP to cover ASP until Cumulative
                                           Breakeven

DRMD gets                         20%      of GP
Step 2
Remaining Gross Profit            80%      Of GP to cover 1999 investment of $38
                                           MUSD

                                  20%      Of GP goes to Solvay Pharmaceuticals

         4.       Solvay Pharmaceuticals will guarantee the loan to Duramed by
                  Merrill Lynch Business Financial Services, Inc. in the
                  principal amount of $20,000,000 subject to approval by Solvay
                  Pharmaceuticals of the required documentation from Merrill
                  Lynch Business Financial Services, Inc. and the granting of an
                  exclusive, first position mortgage, to Solvay Pharmaceuticals,
                  Inc. in the approximately 17 acre tract of land and
                  improvements comprising Duramed's Cincinnati manufacturing
                  facility.

         5.       Duramed shall grant Solvay Pharmaceuticals, or its designee, a
                  worldwide exclusive license to Cenestin(R)outside the U.S.
                  These rights will apply to all countries except for Puerto
                  Rico and the Eastern European countries currently covered by
                  Duramed's existing commitments to Gedeon Richter until such
                  time as those arrangements expire or are terminated. This
                  license will apply on a country-by-country basis and may be
                  exercised with respect to any country at any time within ten
                  months after the date of this letter. During this period,
                  Solvay Pharmaceuticals will advise Duramed of the countries in
                  which it wishes to market Cenestin, and the parties will
                  negotiate in good faith to enter into a mutually agreed
                  license and supply agreement for each country on commercially
                  viable terms to Solvay Pharmaceuticals which, amongst other
                  terms, shall include consideration of the pricing constraints
                  imposed by foreign countries.

                  Unless otherwise agreed between Duramed and Solvay
                  Pharmaceuticals, the term of any such agreement will continue
                  for the term of the Cenestin co-promotion agreement between
                  Solvay Pharmaceuticals and Duramed, as the term of that
                  agreement may be modified by the parties in the future. During
                  the initial ten months period and for a period of two years
                  thereafter, if Duramed receives a bona fide written offer from
                  a third party for Cenestin in a country, Duramed will promptly
                  notify Solvay Pharmaceuticals of the terms of the offer, and
                  Solvay Pharmaceuticals will have the right to negotiate an
                  agreement with Duramed for that country on terms no more
                  favorable to Duramed than the terms offered by the third
                  party. If Duramed and Solvay Pharmaceuticals are unable to
                  agree on the terms of the agreement for a country within two
                  months of the date Duramed notifies Solvay Pharmaceuticals of
                  the third party offer, Duramed may proceed with the third
                  party on the terms previously offered by the third party.

         6.       Duramed shall grant Solvay Pharmaceuticals, or its designee,
                  the option to an exclusive worldwide license to Verapamil SR
                  under a Solvay Pharmaceuticals brand name. This option may be
                  exercised at any time within one year after the date of this
                  letter. During this period, at Solvay Pharmaceuticals'
                  request, Duramed will negotiate, with Solvay Pharmaceuticals a
                  royalty-free licensing and supply agreement for Verapamil SR
                  on industry-standard terms and conditions. Under any
                  agreement, Duramed will agree to manufacture Verapamil SR for
                  Solvay Pharmaceuticals and sell it to Solvay
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                  Pharmaceuticals at a price equal to Duramed's standard cost,
                  plus 15%. If Solvay Pharmaceuticals exercises its right of
                  first refusal and introduces a brand product, Duramed will
                  cease marketing Verapamil SR as a generic drug under Duramed's
                  ANDA.

Both parties agree to diligently pursue the drafting and negotiation of further
documentation incorporating the agreements as set forth above.

If you agree with the foregoing, please sign and return a copy of this letter,
which will then represent the binding agreement of our companies.

Very truly yours,

SOLVAY PHARMACEUTICALS, INC.


By:      /s/ Robert A. Solheim
         --------------------------------------
         Robert A. Solheim, Vice President

Accepted and agreed to this       day
                            -----
of January, 2000


DURAMED PHARMACEUTICALS, INC.


By:      /s/ E. Thomas Arington
         --------------------------------------
         E. Thomas Arington, Chairman and CEO