FDA WILL TRACK REFORMULATED PRODUCTS FOR BIOEQUIVALENCE PROBLEMS

Executive Summary

FDA WILL TRACK REFORMULATED PRODUCTS FOR BIOEQUIVALENCE PROBLEMS under a new system that examines reformulations of all NDAed and ANDAed products. Under the procedures, detailed in an April 12 Federal Register notice, "when the agency reviews the bioavailability of a proposed new formulation, it will compare the bioavailability of the new formulation to the bioavailability of the last formulation for which an in vivo bioequivalence study was conducted," FDA said. "To help FDA implement the new policy," the agency is requesting that "any applicant who proposes to reformulate its product . . . list all previous reformulations of the product, giving the date of each previous bioequivalency study." FDA noted that while the submission of such data is not officially required, it "will help to avoid significant delays in agency processing of applications for new formulations." The agency will be establishing a computerized data base for the information, which "should ultimately permit FDA to retrieve reformulation data without the continued need for the submission of previous reformulation information with each proposed reformulation change," FDA added. The new system is an outgrowth of recommendations made by the agency's bioequivalence task force in its January 1988 report. The task force recommended that FDA solicit information on bioequivalence problems that might arise from reformulations. FDA had issued the report after analyzing data and comments presented at its 1986 bioequivalence hearing. Participants at the hearing, FDA noted, "expressed concern that a drug product could undergo a series of minor reformulations, none of which individually justified a new bioequivalence study, but which could cumulatively result in a major change from the original formulation that should be supported by a new in vivo bioequivalence study." Presently, FDA explained, reviewers generally do not "compare the proposed reformulation with the formulation on which the last bioavailability study had been performed." With this system, it is "at least theoretically possible for the bioavailability of a proposed reformulated product to vary from the approved formulation's without the agency being aware of the degree, or even the existence of, that variation." The new procedures are designed "to prevent such untested differences in bioavailability from developing." FDA is also attempting to better define those types of reformulation changes that should be supported by bioavailability data. To aid in that effort, FDA is requesting that manufacturers submit information on the types of product changes that have "created actual bioavailability problems." FDA is accepting written comments on the new procedures through July 11.