Interpretation of plasma concentration-time curves after oral dosing.
The pharmacokinetic information obtained after oral administration is examined using the two-compartment model. Data were obtained by simulation and experimentally by administering sulfisoxazole by an exponential infusion to rabbits. When the absorption rate constant is allowed to approach alpha, a typical two-compartment oral absorption curve is obtained, which is described by a triexponential equation. However, if the absorption rate constant approaches E2 (the sum of the elimination rate constants out of the peripheral compartment), the data are adequately fit by a one-compartment model, with the calculated absorption rate equal to alpha. The relative error in using a one-compartment model to calculate absorption rate constants for two-compartment data is also evaluated.
D000284:Administration, Oral; D000818:Animals; D007263:Infusions, Parenteral; D007275:Injections, Intravenous; D007408:Intestinal Absorption; D007700:Kinetics; D008954:Models, Biological; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000097:blood*; D011817:Rabbits; D013444:Sulfisoxazole / Q000008:administration & dosage / Q000097:blood; D013997:Time Factors
D004364:Pharmaceutical Preparations; D013444:Sulfisoxazole