Development and Validation of Simple UV Spectrophotometric Methods for Simultaneous Estimation of Ofloxacin and Tinidazole in Combined Tablet Dosage Form

Abstract

The present study aimed to develop and validate two simple, rapid, economical, and accurate UV-visible spectrophotometric methods for the simultaneous estimation of Ofloxacin (OFLOX) and Tinidazole (TZ) in combined tablet dosage forms. Two analytical approaches, namely Vierordt's simultaneous equation method (Method I) and the absorbance ratio (Q-analysis) method (Method II), were developed using 0.1 N sodium hydroxide as the solvent. The absorption maxima of Ofloxacin and Tinidazole were observed at 288 nm and 319 nm, respectively, while an isoabsorptive point was identified at 298 nm. Calibration curves exhibited excellent linearity within the concentration ranges of 2–14 μg/mL for Ofloxacin and 4–20 μg/mL for Tinidazole, with correlation coefficients ranging from 0.998 to 0.999. The developed methods were validated according to International Council for Harmonisation (ICH) guidelines with respect to linearity, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), and assay. Recovery studies performed at 80%, 100%, and 120% concentration levels yielded recoveries between 99.76% and 100.41%, confirming the accuracy of both methods. Precision studies demonstrated %RSD values below 2%, indicating excellent repeatability and intermediate precision. Assay results showed drug contents ranging from 99.92% to 100.90%, demonstrating the applicability of the proposed methods for routine quality control analysis. The developed UV spectrophotometric methods are simple, reliable, cost-effective, and suitable for simultaneous estimation of Ofloxacin and Tinidazole in combined pharmaceutical dosage forms without prior separation.

Keywords: Ofloxacin, Tinidazole, UV-visible spectrophotometry, Simultaneous equation method, Method validation