MEFENAMIC-ACID BIOEQUIVALENCE ASSESSMENT WITH A NEW STATISTICAL PROCEDURE

The bioequivalence of three different formulations of mefenamic acid w as tested using the index xi(2) previously defined by Rescigno. This i ndex is a measure of the distance in Hilbert space of two concentratio n vs time functions; unlike the approach of Westlake which assumes a m ultiplicative model for the AUC and C-max characteristics, this approa ch does not imply any hypotheses on the structure of the data and no p articular model of the absorption or of the elimination processes. The index xi(2) is simply an indication of how similar two formulations a re. Results for this new test were compared with those obtained with t wo other tests, namely 90 and 95% symmetrical confidence intervals of Westlake and two one-sided t-tests of Shuirmann through the 90% confid ence intervals in the ranges 80-125% for AUC and 70-143% for C-max. Re sults of the new test are fully comparable with those obtained using t he other two tests. (C) 1996 The Italian Pharmacological Society.