ABSTRACT
This chapter assesses the utility of single-dose (sd) studies in estimating the bioequivalency of both linear and nonlinear drugs, using the confidence interval method. The role of sd and multiple-dose (md) studies in pharmacokinetics has been well established. Several additional pharmacokinetic relationships have proved useful in predicting md kinetics from sd data. Larger differences were observed between the test and reference mean values and standard errors for the sd data than for the md data, a pattern previously observed with the simulated data for phenytoin. Sd and md studies play a major role not only in the determination of bioequivalency for controlled-release products, but also in the evaluation of their pharmacokinetic characteristics. A rigorous use of sd studies would allow a more quantitative examination of both the drug absorption rate and of dose-dumping in controlled-release products, especially those that exhibit a significant level of drug accumulation.
