Development and validation of ultraviolet spectrophotometric assay method for cefixime and its tablet/capsule formulations

Abstract

Liquid chromatographic methods are described in the 2005 European Pharmacopeia and 2011 British Pharmaceutical Codex for the assay of cefixime antibiotics. These official assay methods are expensive and complex for routine analysis in many pharmaceutical industries in developing countries. A simple, precise and reproducible spectrophotometric method was developed and validated for the determination of cefixime antibiotics and its tablet or capsule formulations. The procedure was applied for the determination of cefixime pure sample, two brands of cefixime tablets (A, B) and one brand of cefixime capsules (C) commercially available in Nigeria. In order to validate the method, the timeabsorbance relationship, optical characteristics (limit of detection, limit of quantitation, wavelength of maximum absorption, slope, linearity, intercept and Beer’s law limits), accuracy, inter-day precision and intra-day precision of the assay method were studied. The absorbance of cefixime in methanol was determined spectrophotometrically at the λ_max of 267 nm. Beer’s law was obeyed in the concentration range of 0.1 to 20.0 mg%. The calibration curve had a regression coefficient of 0.9987 ± 0.0010. Samples were stable for 2 hours. The limit of detection and the limit of quantitation of the ultraviolet spectrophotometric method were found to be 0.0047 and 0.0147 mg% respectively. Percentage recoveries between 99 and 102 % were obtained. The inter-day and intra-day precisions were within acceptable limits. Percentage purity of cefixime brands were 100.90, 114.60 and 119.90 % for brands A, B and C respectively. The proposed spectrophotometric method proved to be simple, robust, economical, required no pre-treatment of the drug and therefore recommended for assay of pure cefixime and its tablet or capsule dosage forms.

Key-words: Cefixime, spectrophotometry, tablet, capsule, assay development.