COMPARISON OF BIOLOGICAL AND CHEMICAL-ASSAYS FOR THE QUANTITATION OF RIFAPENTINE IN HUMAN PLASMA

The purpose of this study was to establish the correlation between bio logical and chemical assays for the quantification of rifapentine in h uman plasma. The bioassay was found to over estimate antibiotic plasma concentration when compared to the high-performance liquid chromatogr aphy (HPLC) assay for rifapentine (r = 0.9538, n = 220). This sons bec ause of the presence of varying amounts of the biologically active 25- O-desacetyl metabolite in tile test samples. A better correlation (r = 0.9804, n = 220) was observed when the bioassay data were compared to combined parent-metabolite HPLC values. Such correlative data are nec essary adjuncts in the establishment of antibiotic susceptibility test breakpoints. (C) 1997 Elsevier Science Inc.