Stability indicating HPLC method development and validation for the simultaneous determination of Azithromycin & Ofloxacin in bulk and its dosage forms

A simple, precise, sensitive and reproducible stability indicating Reverse Phase High Performance Liquid Chromatographic (RP-HPLC) method for determination of Azithromycin and Ofloxacin in tablet dosage form was developed. Chromatographic separation was achieved on Hypersil-Keystone RP C18 (250 4.6 mm, 5m) column maintained at 30 C eluted with mobile phase at flow rate of 1.2 ml/min. The mobile phase consists of Buffer (0.02 M potassium dihydrogenphosphate): methanol: acetonitrile in the ratio 65:25:10 v/v at pH maintained at 3.2 with OPA was used and the determination was carried out at 285 nm. The retention time for Azithromycin and Ofloxacin were 9.7 min and 5.01 respectively. The linearity was found in the range of 5?50 ?g/ml for Azithromycin and 4?40 ?g/ml for Ofloxacin. In stability studies the drugs were well separated from degradation products. The degradation was studied in the individual standard drugs, their mixture and formulation which gave the idea about the orgin of the degradant products. The analytical method was validated as per ICH guideline for linearity, accuracy, precision, and specificity, limit of detection, limit of quantification, stability in analytical solution etc. and method can be extended to the analysis of Azithromycin and Ofloxacin in tablet formulations.