Abstract

The use of truncated area under the curve has been encouraging in evaluation of bioequivalence trials. The objective of the investigation was to compare the applicability and accuracy of truncated area under the curve from 0 h to time t h versus area under the curve from 0 h to infinity and also to determine whether limiting the number of blood samples would influence its effectiveness. The evaluation was based on the retrospective analysis of five bioequivalence studies. All drugs administered were immediate-release formulations with half lives in the range of 3.66- 32.4 h. In all the trials considered, point estimators and 90% confidence intervals of the ratio of the mean areas under the curve of test and reference formulations, were comparable in the case of truncated and untruncated trials. However, the duration of truncation was not equal for all the drugs and was influenced by the measurability of concentration at truncation time point, variability of the concentration-time data and frequency of blood sampling. The results of this study also demonstrated that a limited number of blood samples taken at appropriate times, can sufficein bioequivalence studies when the trial is truncated.