Bioavailability studies immediate-release drug product

Bioavailability studies for IVIVC development should be performed with enough subjects to characterize adequately the performance of the drug product under study. In prior acceptable data sets, the number of subjects has ranged from 6 to 36. Although crossover studies are preferred, parallel studies or cross-study analyses may be acceptable. The latter may involve normalization with a common reference treatment. The reference product in developing an IVIVC may be an intravenous solution, an aqueous oral solution, or an immediate release product. 

Amidon, G.L. Lennernas, H. Shah, V.P. Crison, J.R. A theocratical basis for the biopharmaceutic drug classification the correlation of in vitro drug product dissolution and in vivo bioavailability. Pharm. Res. 1995,12, 413-420. FDA Guidance for Industry Waiver of In Vivo Bioavailability and Bioequivalence Studies for Immediate-Release Solid Oral Dosage Forms Based on a Biopharmaceutics Classification System, August 2000. 

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