POOLING PLASMAS FOR A RAPID ANSWER IN PHARMACOKINETIC STUDIES - APPLICATION TO A BIOEQUIVALENCE STUDY OF HYDROCORTISONE TABLETS

Two methods of plasma pooling in pharmacokinetic studies are described . The first method allows the estimation of the average plasma profile of all subjects receiving a given dose or formulation, with at most a s many assays as there are time points. The second method allows to es timate the individual AUCs of all subjects with only a single assay fo r each drug administration. These techniques were successfully employe d to predict the final results of a bioequivalence study of two formul ations of hydrocortisone 10 mg tablets. Plasma pooling methods can pro vide early partial information on the results of pharmacokinetic studi es. They can be most useful in bioequivalence studies, where early est imates of the average curves and individual AUCs can lead to a decisio n not to proceed with all the assays, if bioequivalence appears unlike ly. The pooling methods may also have useful potential applications in Phase I ascending dose-tolerance studies and in the field of pharmaco kinetic studies in small animals. Further studies are necessary to tes t these methods in order to gain more information on their reliability in the decision-making process in these fields as well as in bioequiv alence studies.