Par Pharmaceutical Terminates Partnership With Advancis Pharmaceutical

SPRING VALLEY, N.Y. – August 03, 2005 – Par Pharmaceutical Companies, Inc. today announced that it has terminated its partnership agreement with Advancis Pharmaceutical Corporation. The decision to terminate the partnership follows the recent release of results from Advancis' Amoxicillin PULSYS Phase III clinical trials. In both clinical trials, the Amoxicillin PULSYS product failed to achieve the desired microbiological and clinical endpoints. In 2004, Par entered into the agreement with Advancis to develop and market a novel formulation of the antibiotic amoxicillin.

Under the terms of the agreement, Par made quarterly payments to Advancis to fund the development of the Amoxicillin PULSYS product. Par's $4.75 million payment for the third quarter of 2005 fulfills Par's final obligation to Advancis. By terminating the partnership at this time, Par is no longer responsible for the fourth-quarter installment of $4.75 million, which would have represented Par's final payment to Advancis. If Advancis succeeds in developing and marketing any amoxicillin PULSYS product, Par will be reimbursed from the proceeds for up to half of its development expenses.

Par Pharmaceutical Companies, Inc. develops, manufactures and markets generic pharmaceuticals through its principal subsidiary, Par Pharmaceutical, Inc. The company is also developing an additional line of branded pharmaceutical products for specialty markets, the first of which is Megace(R) ES. Par currently manufactures, markets or licenses more than 90 prescription drugs. For press release and other company information, visit http://www.parpharm.com.