An Interactive Sas/a~ System for Assessing Bioequivalence

Testing the equivalence of treatments in a two-period crossover design setting occurs often in the pharmaceutical industry. These studies usually compare the rate and extent of absorption of two different drugs or two formulations of the same drug, where one is the accepted standard therapy. The commonly accepted rule for concluding bioequivalence requires the 90% confidence interval for the mean tesVstandard ratio of AUG and Cmax to be contained in the range (80,120)%. Sample size is usually determined based on meeting this criterion. In order to improve efficiency and consistency in the analysis and reporting of data from bioequivalence trials, a SAS/ A~ application system for analyzing data from a two-period, two-treatment crossover design was created. The system contains four main sections: sample size/power, analysis, bioequivalence and utility. With the expanded capabilities of SASIAF in Version 6 and the use of SCL, the system is very powerful, yet extremely user friendly. This paper first presents a brief overview of the design and analysis of data from a two-period crossover study. Primary focus is then directed to the interactive SAS/ AF system and those functions of the system related to the analysis of the data and the assessment of bioequivalence.