Purpose: To develop and validate stability-indicating reversed phase high performance liquid chromatographic method for simultaneous determination of ketotifen fumarate and cetirizine dihydrochloride in solid dosage forms.

Method: Chromatographic separation was achieved on Grace Smart C18 column (250 × 4.6 mm, 5 μm) using an isocratic mobile phase that consisted of acetonitrile and 10 mM disodium hydrogen phosphate buffer (pH 6.5) in a ratio of 45:55 % v/v at a flow rate of 1 mL/min. Detection was carried out at 230 nm. Salbutamol sulphate was used as an internal standard. The drugs were exposed to hydrolytic (acid and alkaline), oxidative, reductive and neutral stress conditions, and the stressed samples analyzed by the proposed method. Validation of the method was carried out as per International Conference of Harmonization (ICH) guidelines.

Results: The retention time for ketotifen, salbutamol and cetirizine was 2.05, 5.37 and 6.77 min, respectively. In stress studies, it was observed as cetirizine was more labile in acidic, oxidative and neutral conditions than ketotifen. Both the drugs were found comparatively stable in alkaline, neutral condition and labile in reductive condition. The method was linear in the concentration range of 1 - 30 μg/mL and 10 - 300 μg/mL for ketotifen and cetirizine, respectively.

Conclusion: The developed method is specific and stability-indicating as no interfering peaks of degradants and excipients were observed. Thus, the method is suitable for application in the simultaneous quality control of both drugs.