Questcor Completes Divestiture of Three Products for $28.3 Million.

UNION CITY, Calif. -- Questcor Pharmaceuticals, Inc. (AMEX:QSC), a specialty pharmaceutical company that develops and commercializes novel therapeutics for the treatment of neurological disorders, today announced the completion of a transaction to divest its non-core pharmaceutical products, in accordance with its new central nervous system (CNS) strategy. Questcor completed the sale of its Nascobal(R), Ethamolin(R) and Glofil(R)-125 products to QOL Medical LLC for $28.3 million, plus the assumption by QOL of the obligation to pay Nastech Pharmaceutical Company Inc. (NasdaqNM: NSTK) $2 million on the issuance by the US Patent and Trademark Office of a patent on Nascobal Nasal Spray.

"This is a pivotal event in our previously-announced plans for transforming Questcor into a true CNS-focused specialty pharmaceutical company," stated James L. Fares, President and CEO of Questcor. "This transaction raises significant capital for Questcor for future business-building activities centered in the Neurology field, while avoiding any shareholder dilution. Questcor personnel can now begin focusing exclusively on supporting H.P. Acthar(R) Gel and building Questcor's CNS portfolio."

Through the remainder of 2005, Questcor will continue focusing its sales and marketing efforts on promoting H.P. Acthar Gel to neurologists. In order to expand its CNS portfolio, Questcor is continuing to evaluate opportunities to acquire currently marketed products and to build a pipeline of commercially attractive development opportunities. Questcor expects to provide further updates on these activities by the end of 2005.

Edgemont Capital Partners served as exclusive advisor to Questcor on this transaction.

About Questcor

Questcor Pharmaceuticals, Inc.(R) (AMEX:QSC) is a specialty pharmaceutical company that develops and commercializes novel therapeutics for the treatment of neurological disorders. Questcor currently markets H.P. Acthar(R) Gel (repository corticotropin injection), an injectable drug indicated for the treatment of exacerbations associated with Multiple Sclerosis. For more information, please visit www.questcor.com.

About QOL

QOL Medical LLC is a specialty pharmaceutical company dedicated to improving quality of life for the patients we serve, their families and caregivers. QOL Medical currently markets Sucraid (sacrosidase) oral solution. For more information, please visit www.qolmed.com.

Note: Except for the historical information contained herein, this press release contains forward-looking statements that involve risks and uncertainties. Such statements are subject to certain factors, which may cause Questcor's results to differ from those reported herein. Factors that may cause such differences include, but are not limited to, Questcor's ability to accurately forecast and create the demand for each of its products, the gross margins achieved from the sale of those products, Questcor's ability to enforce its exchange policy, the accuracy of the prescription data purchased from independent third parties by Questcor, the sell-through by Questcor's distributors, the inventories carried by Questcor's distributors, and the expenses and other cash needs for the upcoming periods, Questcor's ability to obtain finished goods from its sole source contract manufacturers on a timely basis if at all, Questcor's need for additional funding, uncertainties regarding Questcor's intellectual property and other research, development, marketing and regulatory risks, and, to the ability of Questcor to implement its strategy and acquire products and, if acquired, to market them successfully as well as the risks discussed in Questcor's annual report on Form 10-K for the calendar year ended December 31, 2004 and other documents filed with the Securities and Exchange Commission. The risk factors and other information contained in these documents should be considered in evaluating Questcor's prospects and future financial performance.

Questcor undertakes no obligation to publicly release the result of any revisions to these forward-looking statements, which may be made to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.