Exhibit 10.104

CERTAIN MATERIAL (INDICATED BY AN ASTERISK) HAS BEEN OMITTED FROM THIS DOCUMENT PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED MATERIAL HAS BEEN FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION.

4^th Amendment to the

CAPTISOL SUPPLY AGREEMENT

Dated as of

December 20^th, 2002 and amended July 29, 2005,

March 1, 2007 and January 28, 2008

BY AND BETWEEN

CYDEX PHARMACEUTICALS, INC.

AND

THE HOVIONE GROUP

Dated as of September 23, 2009

4^th AMENDMENT TO THE CAPITSOL SUPPLY AGREEMENT

This 4^th amendment to the Captisol Supply Agreement (the “AGREEMENT”) is entered into as of September 23, 2009, by and between:

This 4^th Amendment to the Captisol Supply Agreement is hereafter referred to as “Amendment No. 4”.

BACKGROUND

Both parties declare that the original intent of the AGREEMENT entered into has been and remains valid. The parties feel that it is in the best interests of both parties to clarify and update certain terms set forth in the AGREEMENT. Specifically the parties have agreed to the terms and conditions related to reimbursing to CYDEX the original Loures Engineering Services costs for the Captisol program, clarify invoicing procedures and extending the current term of the AGREEMENT.

AGREEMENTS

NOW, THEREFORE, in consideration of the mutual promises hereinafter made and the mutual benefits derived from this Amendment No. 4, and other good and valuable consideration, the receipt and sufficiency of which is acknowledged, the parties hereto, intend to be legally bound, hereby agree to as follows:

““INITIAL TERM” means the period commencing upon the EFFECTIVE DATE and ending on December 31, 2019.”

“4.2 (h) Reimbursement for Loures Engineering Services. Commencing on the 1^st of January, 2010, HOVIONE will [***] the UNIT PRICES of CAPTISOL by [***] of CAPTISOL purchased by CYDEX from HOVIONE. This [***] will apply to all CAPTISOL purchased after the 1^st of January, 2010 up to [***] of CAPTISOL purchased or on March 31^st, 2014 irrespective of the quantity purchased. Once the total amount of [***] have been purchased or the period of time for the said reimbursement expires, namely: on March 31^st, 2014, the reimbursement shall expire and the UNIT PRICES will return to the standard calculation as outlined in Amendment No. 3 executed on the 28^th January, 2008.”

“For clarity, HOVIONE shall not issue invoices for CAPTISOL prior to the date of actual shipment of CAPTISOL by HOVIONE for deliveries to CYDEX to fulfill CYDEX’s purchase orders, even if HOVIONE has earlier released the relevant quantities of CAPTISOL for quality control purposes unless agreed to in writing by both CYDEX and HOVIONE.”

Signature Page to Follow

IN WITNESS WHEREOF, the parties, through their authorized representatives, have duly executed this Amendment No. 4 as of the date first written above.