Absorption Kinetics of Carbenicillin Phenyl Sodium and Carbenicillin Indanyl Sodium in Man

Abstract

Carbenicillin phenyl sodium (CFPC) and carbenicillin indanyl sodium (CIPC), which are prodrugs of carbenicillin (CBPC), were orally administered to three volunteers at various doses. The absorptions of these prodrugs were compared by means of moment analysis using urinary excretion data. CFPC showed linear absorption kinetics at 0.5, 1.0, and 1.5 g doses. On the other hand, the urinary recovery after oral administration of CIPC decreased and the mean absorption time (MAT) increased as the dose was increased from 0.5 to 1.5 g. Computer simulations by the Runge-Kutta method confirmed the occurrence of capacity-limited absorption of CIPC.