Development and validation of microbial bioassay for the quantification of potency of the antibiotic cefuroxime axetil

Cefuroxime is a semi-synthetic antibiotic of the cephalosporin group and has broad-spectrum antimicrobial activity. HPLC methods, detailed in various pharmacopoeias, are generally used for the quantitative determination of the potency of cefuroxime but are unable to determine its bioactivity against microorganisms. In comparison to HPLC methods bioassay methods are simple and inexpensive however, a bioassay for the determination of both the potency and bioactivity of cefuroxime has not yet been reported in any pharmacopoeia. This article is focused on the development of a bioassay method for the quantification of cefuroxime axetil in pharmaceutical preparations. The bioassay was performed with different microbial strains and Kocuria rhizophila ATCC-9341 was selected as the most susceptible microorganism against cefuroxime axetil. The percent potency of market samples were estimated by a two-level bioassay method. The potency of market samples of Biocef, Ceftech and Ceftum were found to be 100.71% (RSD 1.09%), 101.07% (RSD 1.16%) and 100.44% (RSD 1.08%), respectively. The Biocef intermediate precision RSD between days and between analysts were 1.08% and 1.01%, respectively. The specificity of the bioassay for the analysis of Biocef was also studied in parallel with the Pharmacopoeial HPLC method and the potency was calculated as 101.09%. Results show that a bioassay method can be used for the quality control of cefuroxime axetil in raw materials and pharmaceutical preparations.