DRUG PRODUCT ACTIVE INGREDIENT IN FINAL DOSAGE FORM

DRUG PRODUCT ACTIVE INGREDIENT IN FINAL DOSAGE FORM must be used as the basis for ANDA suitability petitions, FDA told Rowell Labs in a June 5 letter denying the firm's petition for ANDA suitability of 5-aminosalicylic acid suppositories, 500 mg. The reference drug in Rowell's petition is S.A.S.-500 (salfasalazine tablets). FDA Office of Drug Standards Director Peter Rheinstein, MD, stated that "to submit an ANDA directly, without a petition, the product that is the subject of an ANDA must, among other things, consist of active ingredients that are the same as those of the previously approved product to which the ANDA refers." Rheinstein said "the term active ingredient in the [ANDA/patent restoration] Act refers to the active ingredient found in the final disage form prior to the administration of product to the patient, rather than to any resultant form the drug may take following administration." He added that although Rowell cited in its petition "some scientific data in support of the theory that when S.A.S. (salfasalazine) is administered orally it breaks down into sulfapyridine (SP) and 5-ASA, the originally administered product differs from the listed drug." Rheinstein noted that "5-ASA alone has never been approved by the agency." Rheinstein pointed out that the Act does permit substitution of different active ingredients if the reference listed drug is a combination product. FDA also denied Rowell's request for the indication of ulcerative proctitis for 5-aminosalicylic acid suppositories since the indication "is a new use, one not currently approved for the 'listed' drug product salfasalazine." Rheinstein said a request for a new indication "would require, among other things, investigations to demonstrate the effectiveness of the proposed new indication and thus could not be approved" under the Act.