Comparative Quality Evaluation of Marketed Cefixime Trihydrate Tablet Brands Available in Bangladesh

In low- and middle-income countries, antibiotic resistance is rising rapidly because of poor medication adherence, polypharmacy, and weak regulatory enforcement, while substandard and counterfeit medicines further accelerate resistance. Cefixime trihydrate, a broad-spectrum third-generation cephalosporin, is a widely used and frequently prescribed antibiotic in Bangladesh. This study evaluated quality attributes, including % drug content and % drug release, of eight commonly prescribed cefixime 200 mg tablet brands and compared them with the innovator-equivalent brand.

Chromatographic separation was performed on a reversed-phase C18 column with UV detection at 282 nm (column temperature 30°C; run time 8 min), using methanol and 0.01 M KH₂PO₄ buffer (pH 4.5) at 1 mL/min. Dissolution studies were conducted using a USP Apparatus 2, and antimicrobial activity was assessed via the Kirby-Bauer disc diffusion method.

All nine brands met USP potency standards (90%-110%) and dissolution criteria (≥ 75% drug release within 45 min). A one-way ANOVA with Dunnett's test (α = 0.05, two-tailed; critical value = 2.731) revealed significant differences between Tab. A, Tab. E, and Tab. F and the reference brand at 45 min. However, among local brands, seven out of eight (87.5%) complied with the FDA-recommended difference factor (f1) and similarity (f2) factor criteria. Zone of inhibition studies showed good antimicrobial activity across most of the brands at 5 μg disc load.

Seven out of the eight local brands met the f1/f2 similarity criteria relative to the reference, indicating comparable in vitro dissolution behavior, whereas one brand (Tab. C) did not. These results emphasize the need for continuous quality surveillance to ensure therapeutic equivalence and combat antimicrobial resistance.