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                                                                   Exhibit 10.21

                               December 10, 2001

To:  Akorn, Inc.
     Akorn (New Jersey), Inc.

                     Re: Proposed Loan from NeoPharm, Inc.

Gentlemen:

     Reference is made to (i) the Forbearance Agreement dated as of July 12,
2001 (the "Forbearance Agreement"), by and among Akorn, Inc., a Louisiana
corporation, Akorn (New Jersey), Inc., an Illinois corporation, and The Northern
Trust Company, an Illinois banking corporation, and (ii) the "Credit Agreement"
(as defined in the Forbearance Agreement). All capitalized terms used and not
otherwise defined herein shall have the same meanings as in the Credit
Agreement.

     You have advised us that the Borrowers propose to (i) obtain a loan from
NeoPharm, Inc., a Delaware corporation ("NeoPharm"), in the principal amount of
$3,250,000 (the "NeoPharm Loan"), pursuant to a Promissory Note in the form
attached hereto as Exhibit A (the "NeoPharm Note"), and (ii) expend the proceeds
of the NeoPharm Loan for the purpose of undertaking and completing the
"Lyophilization Ramp-Up" (as defined in the NeoPharm Note). The NeoPharm Loan
would be obtained, and the NeoPharm Note would be executed and delivered, in
connection with a Processing Agreement between Akorn and NeoPharm in the form
attached hereto as Exhibit B.

     The act of Akorn in obtaining and becoming obligated for the NeoPharm Loan,
Akorn's execution and delivery of the NeoPharm Note, and Akorn's expenditures
for the Lyophilization Ramp-Up will or may constitute a violation of one or more
provisions of the Credit Agreement, and will or may cause one or more of the
Forbearance Conditions (as defined in the Forbearance Agreement) to fail to be
satisfied. You have requested that the Lender waive any such violation of the
provisions of the Credit Agreement and any such failure of one or more of such
Forbearance Conditions to be satisfied (the "Waiver").

     The Lender hereby grants the Waiver, but only on and subject to the
following conditions:

          (i)  The NeoPharm Loan will be on the terms and conditions set forth
               in the NeoPharm Note.

          (ii) Contemporaneously with the execution and delivery of this letter
               NeoPharm and the Borrowers enter into a Subordination, Standby
               and Intercreditor Agreement with the Lender in the form attached
               hereto as Exhibit C (the "NeoPharm Subordination Agreement").


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     (iii) The Waiver shall be in effect only so long as the NeoPharm
Subordination Agreement is in effect and there is no failure on the part of
NeoPharm or either of the Borrowers to be in compliance with all of the terms
and conditions of the NeoPharm Subordination Agreement.

     (iv)  The Waiver shall apply only to the specific matters referred to in
this letter and shall not extend or relate to any other related or unrelated
matters, and neither the granting of the Waiver nor anything contained in this
letter shall be construed to obligate the Lender to grant any other waivers to
the Borrowers.

     (iv)  The Borrowers hereby (A) confirm and reaffirm all of their
obligations under the "Documents" (as defined in the Forbearance Agreement) and
under the Forbearance Agreement; (B) acknowledge and agree that the Lender, by
granting the Waiver, does not waive any existing or future default or event of
default under any of the Documents or the Forbearance Agreement, or any rights
or remedies under any of the Documents or the Forbearance Agreement, except as
expressly provided herein; (C) acknowledge and agree that the Lender has not
heretofore waived any default or event of default under any of the Documents, or
any rights or remedies under any of the Documents, except as provided in the
Forbearance Agreement; and (D) acknowledge that they do not have any defense,
set-off or counterclaim to the payment or performance of any of their
obligations under the Documents or other Forbearance Agreement.

     (v)  The Borrowers shall expend the proceeds of the NeoPharm Loan solely to
pay or reimburse costs incurred in connection with the Lyophilization Ramp-Up,
and the Borrowers shall not expend any funds in excess of the proceeds of the
NeoPharm Loan on the Lyophilization Ramp-Up.

     (vi) The Borrowers shall provide the Bank with reports no less often than
once during each of the periods ending on the 15th day and the last day of each
calendar month, commencing with the month of December, 2001, as to the progress
of Lyophilization Ramp-Up, including, without limitation, information concerning
the budget and time schedule and changes to the budget and time schedule for the
Lyophilization Ramp-Up, contracts and commitments entered into, and payments
made and scheduled to be made. To the extent that the Lyophilization Ramp-Up
involves payment for labor, materials or property the furnishing of which could
give rise to mechanics lien claims against the premises commonly known as 1222
West Grand, Decatur, Illinois, the Borrower shall make such payment only in
exchange for waivers and releases of such mechanics lien claims, and at the time
of making each such payment, the Borrowers shall furnish to the Bank a date down
endorsement to Chicago Title Insurance Company Policy No. 120090185 insuring the
Bank's mortgage on such property, covering the date of such payment and raising
no exception for mechanics lien claims.

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If the foregoing terms are acceptable to you, please so indicate by signing
below.

                                   Very truly yours,

                                   THE NORTHERN TRUST COMPANY

                                   /s/ Olga Georgiov

                                   Olga Georgiov
                                   Vice President


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