A Stability Indicating RP-HPLC Method for Simultaneous Estimation of Salbutamol, Carbocisteine and Theophylline in Combined Tablet Dosage Forms

A rapid and sensitive stability indicating RP-HPLC method was developed for simultaneous estimation of salbutamol, carbocisteine and theophylline in combined tablet formulations. Chromatography was carried out on a Discovery HS C18 HPLC Column at 35 °C (250 x 4.6 mm; 5m) by eluting with a mobile phase consisting of a 50:50 v/v mixture of acetonitrile and 0.1 % orthophosphoric acid in water at a flow rate of 1.0 mL/ min. The detection wavelength was set at 215 nm. Accuracy was assessed by using standard addition method. The developed HPLC method was validated with respect to precision, specificity, accuracy, linearity and robustness. Forced degradation studies on the formulation were conducted by adopting the proposed method to assess the stability of the analytes under acid, base, peroxide, thermal and photolytic conditions and suitability of the method to resolve the degradation products.