GENERIC DRUG ORAL EXTENDED-RELEASE BIOEQUIVALENCE/DISSOLUTION GUIDANCE

GENERIC DRUG ORAL EXTENDED-RELEASE BIOEQUIVALENCE/DISSOLUTION GUIDANCE issued Sept. 9 by FDA's Office of Generic Drugs. The guidance "describes in vivo bioequivalence studies and in vitro dissolution testing recommended to applicants intending to submit ANDAs for extended-release products administered orally." The guidance does not apply to delayed-release products, FDA noted. The agency characterizes the guidance as a more formal statement of what has been its informal policy for oral extended- release generics. For a demonstration of in vivo bioequivalence, the guidance recommends three studies: "a single-dose, randomized, two-period, two-treatment, two-sequence crossover study under fasting conditions"; "a single-dose, randomized, three-treatment, three- period, six-sequence, crossover, limited food effects study"; and "a multiple-dose, steady-state, randomized, two-treatment, two- period, two-sequence crossover study under fasting conditions." "Quality control of the manufacture of an extended-release formulation after approval may be assessed, in part, through performance of in vitro dissolution tests," the guidance states. OGD recommends that dissolution testing be performed on 12 "individual dosage units of the test and reference products used in the bioequivalence studies." The guidance states that dissolution profiles should be generated at different pH ranges due to "the potential for pH dependence of drug release." OGD is also developing a guidance on post-approval scale-up of oral extended-release products. The document will attempt to wed the bioequivalence guidance and the recommendations of a September 1992 FDA/U.S. Pharmacopoeia/American Association of Pharmaceutical Sciences workshop on scale-up of oral extended-release drug forms. The "Workshop II" report on extended-release scale-up was released in May at a third workshop, which looked at scale-up of liquid and semi-solid drugs.