Evaluation of controlled release formulations: estimation of the duration of the zero-order absorption and ascertainment of absorption kinetics.

A compartmental approach for estimating the duration of the zero-order absorption was developed. For drugs obeying one-compartment model disposition, the estimation is based on an explicit relationship while an iterative process is required for drugs represented by two-compartment kinetics. A method based on a double graphical plot for ascertaining absorption kinetics for drugs exhibiting one-compartment model disposition was also developed.