ABSTRACT:
This research aimed to develop and validate a simple, precise, accurate, sensitive, and low- cost microbiological assay using a one-level agar diffusion method (5+1) to determine the potency and biological activity of cefotaxime sodium in its pharmaceutical formulations not previously mentioned in any pharmacopeia or previous studies, and to use this validated method to evaluate the microbiological equivalence in vitro of cefotaxime sodium formulations. Klebsiella pneumoniae (ATCC-13885) strains exhibiting the highest sensitivity to cefotaxime sodium were selected. Several factors influencing the microbiological assay were optimized, including the standard solution concentration, incubation temperature and duration, the buffer pH, and the bacterial suspension concentration. The method validation results were satisfactory for linearity (R2=0.996), accuracy (99.4%), precision (repeatability RSD 1.47%, intermediate precision RSD 1.79%), and robustness (RSD ?2%). Five local commercial preparations and a brand preparation of cefotaxime sodium were assayed using the developed microbiological method. Their potencies ranged from 94.93% to 103.03%. One-way ANOVA revealed significant differences between the local commercial preparations and a brand preparation, with the brand preparation exhibiting the highest potency at 103.03%. The developed microbiological assay could be applied in pharmaceutical quality control laboratories to determine cefotaxime sodium in its pharmaceutical formulations and to assess the in vitro microbiological equivalence of commercial preparations. To resolve the ongoing debate in the Syrian medical community regarding the interchangeability between local preparations and the brand preparation, since all preparations were within the acceptable range, local commercial preparations can be considered a cost-effective and efficacious alternative to the brand preparation.