Abstract: The present work describes a simple, precise and accurate HPTLC method for its estimation as bulk and in tablet dosage form. The chromatographic separation was carried out on precoated silica gel 60 F₂₅₄ aluminium plates using mixture of methanol: hexane : ammonia  (8:3:1v/v/v) as mobile phase and densitometric evaluation of spots were carried out at 265nm using Camag TLC scanner-3 with WINCAT 1.3.4 version software. The experimental parameters like band size of spot applied, chamber saturation time, solvent front migration, slit width etc were critically studied and optimum conditions were evolved. The drug was satisfactorily resolved with Rf value 0.73 ± 0.06.The linear regression analysis data for the calibration plots showed good linear relationship with concentration range of 200–1000 ng.spot^-1. The mean value of correlation coefficient, slope and intercept were 0.9986. The method was validated for precision, robustness and recovery. The limits of detection and quantitation were 29 and 65 ng.spot^-1, respectively. Statistical analysis proves that the method is repeatable and selective for the estimation of the drug. The drugs were separated on silica gel 60 F₂₅₄ plates using suitable combination of solvents as mobile phase. The validation parameters, tested in accordance with the requirements of ICH guidelines, prove the suitability of methods.

Keywords: Rifaximin; HPTLC, ICH guidelines.