METERED DOSE NITROGLYCERIN PROVIDES "SPECIAL BENEFITS"

METERED DOSE NITROGLYCERIN PROVIDES "SPECIAL BENEFITS" for angina patients, FDA said in approving a Rorer petition to allow use of chlorofluorocarbon in a metered dose nitroglycerin delivery system. The agency made a similar ruling regarding chlorofluorocarbon use in Fisons' metered dose cromolyn sodium. In a July 24 Federal Register notice, FDA said that it "tentatively agrees that the use of metered dose nitroglycerin and metered dose cromolyn sodium provide special benefits for angina pectoris patients and asthmatic patients, respectively." The agency added that it "tentatively agrees that the benefits these products provide would be unavailable without the use of chlorofluorocarbons." According to the FDA notice, the Rorer petition states that the firm's metered dose nitroglycerin product "provides a substantial health benefit that would not be obtainable without the use of chlorofluorocarbon." FDA noted that the petition "contends that the delivery system and convenient size of the product would allow the patient to easily use the product and obtain quick relief during an attack without having to open a bottle and fumble with small tablets." In its petition, Rorer also maintains that "only a chlorofluorocarbon can result in a product that is stable and that dispenses the required number of doses with acceptable accuracy, reproducibility, and uniformity." Rorer is the first firm to petition FDA for the addition of nitroglycerin to the list of chlorofluorocarbon uses considered "essential." FDA approval of the use of chlorofluorocarbons indicates that the firm may be nearing NDA approval for a metered dose nitroglycerin product. In February, Parke-Davis filed a petition with FDA seeking clearance to begin IND studies of a sublingual nitroglycerin product in an aerosol drug delivery system that also made use of chlorofluorocarbbns as propellants. On July 5, FDA granted Parke-Davis' request to begin clinical studies of its aerosol nitroglycerin product. The Parke-Davis petition said that the purpose of the studies is "to collect data to show that the use of chlorofluorocarbons is essential in a metered-dose aerosol form of nitroglycerin for sublingual administration to humans" ("The Pink Sheet" March 18, p. 3). At that time, Parke-Davis said that the use of an aerosol delivery system would require a full NDA for marketing approval. FDA noted that according to data presented by Fisons, its metered dose cromolyn sodium may have advantages over other delivery systems. The petition "includes data showing that the turbo-inhaler delivery system currently being marketed requires considerable skill to use, making it unsuitable for adults suffering poor inspirational capacity, handicapped and elderly patients, as well as for small children," FDA pointed out. In addition, FDA said, the Fisons petition also asserts that other delivery systems, such as a hand-operated pump or compressed gases "could not provide as safe and uniform dispersal of the drug in proper size particles as a chlorofluorocarbon propellant."