Bioequivalence and Bioavailability Forum

Hi Dixit,

FDA Guidance for Industry Handling and Retention of BA and BE Testing Samples: May 2004
See section V

V. QUANTITY OF RESERVE SAMPLES
The quantity of reserve samples should be sufficient to permit the Agency to perform five times all of the release tests required in the application or supplemental application. The rationale for requiring the five times quantity is provided in the final rule. The clinical investigator can obtain the amount that constitutes the five times quantity from the sponsor and/or drug manufacturer. For solid oral dosage forms (e.g., tablets, capsules), an upper limit of 300 units each for the test article and reference standard can be considered sufficient to meet the five times quantity. Because the Agency has limited experience with the retention and testing of non-solid oral dosage forms, the Agency is unable to recommend an upper limit for the retention of non-solid oral dosage forms at this time. In the case of a reference standard that is an extemporaneously compounded solution or suspension or a reconstitutable powder, we recommend that the pure active ingredient and the unconstituted powder be retained. For a multisite BA or BE study, we recommend that the total amount of reserve samples to be retained across all testing facilities satisfy the five times quantity requirement. Each site is asked to retain a reasonable amount of test article and reference standard to be determined by considering (1) the total number of testing facilities participating in the study, (2) the number of subjects expected to be enrolled at each testing facility, and (3) a minimum limit (e.g., 5 dose units) for each of the test articles and reference standards. If the reserve samples from more than one testing facility are transferred to an independent third party for storage, we recommend that the independent third party segregate the reserve samples from the various testing facilities so that any given reserve sample can be unambiguously associated with the testing facility from which it came.


Best Regards
Dr. Brijesh

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Edit: Guidance linked. [Helmut]