NARROW THERAPEUTIC RANGE DRUGS AUDITED BY FDA

NARROW THERAPEUTIC RANGE DRUGS AUDITED BY FDA "virtually all...meet applicable standards of purity and quality," the agency declared in a Sept. 12 press release. FDA's conclusion is based on the testing of samples from 429 batches of 24 different narrow therapeutic range drugs from 73 generic and brandname manufacturers. FDA attempted to test at least three different batches from each manufacturer of each drug. The sampling program was initiated in November 1989 in response to concerns about the quality of generic drugs raised in the wake of the generic drug scandal. HHS Secretary Sullivan declared in the release: "These results should be reassuring to consumers who use generic drugs, since the drugs that were examined are the kind that critics of generics are most likely to claim could cause problems." All batches "met the required quality standards except five batches of aminophylline tablets from two manufacturers which were found to contain incorrect amounts of a necessary stabilizing ingredient," FDA said, adding that "samples from four other manufacturers were tested and found to be satisfactory." The manufacturers of the deficient asthma products, West-Ward Pharmaceuticals and Duramed Pharmaceuticals, have recalled the five batches, the agency noted. Duramed has also been recalling all other lots of its aminophylline line. "FDA has been working with both firms to eliminate the problems that caused the five lots to fail," the release says. In August, Duramed began recalling its wholesale-level stock of aminophylline after having announced suspension of manufacturing and shipping in May. Duramed maintains that the amount of the stabilizing ingredient, ethylenediamine, in its aminophylline product is within specifications, and that an inert ingredient is interfering with the USP test method and causing a "false high" reading for ethylenediamine. The results of the audit were discussed by Office of Compliance Director Daniel Michels at the National Association of Pharmaceutical Manufacturers' mid-year meeting in June. FDA has not yet released the complete survey findings. Text from the sampling survey notes that FDA also discovered that Wyeth-Ayerst's Mysoline (primidone) "complies with the NDA (which was approved many years ago) but did not meet the dissolution requirement incorporated into the USP in 1982." The firm reformulated the product and submitted an NDA supplement to make the product consistent with USP requirements, the survey notes. FDA also found several batches of theophylline products in which "discrepancies exist between approved ANDA test methodology and current USP methodology." The survey adds that "while the products involved are not defective or in serious violation of the Act, action will be taken to rectify these discrepancies as appropriate." FDA also issued a video news release on the audit results. The video includes Center for Drug Evaluation and Research Director Carl Peck discussing the problem of the two aminophylline products not meeting USP specifications for ethylenediamine, and Public Citizen Health Research Group Director Sidney Wolfe, MD, speaking about the safety and value of generic drugs.