TY - JOUR T1 - Oral Bioavailability and First-Pass Effects JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 1329 LP - 1336 VL - 25 IS - 12 AU - K. C. Kwan Y1 - 1997/12/01 UR - http://dmd.aspetjournals.org/content/25/12/1329.abstract N2 - Existing experimental strategies for the in vivoevaluation of factors affecting oral bioavailability have been reviewed. Based on concepts that have evolved, an integrated set of strategies emerges that appears capable of providing estimates of the individual contributions attributable to absorption, losses in the gut lumen, and first-pass elimination in the gut wall and the liver. The only assumptions are linear pharmacokinetics and constant clearance between treatments. These methods are also suitable for the assessment of metabolite bioavailability after drug administration and the quantitative determination of sites of biotransformation and metabolite formation in vivo. The American Society for Pharmacology and Experimental Therapeutics ER -