The objective of the study was to develop a economical , accurate, precise and rapid a UV spectrophotometric i.e. third order derivative method for the simultaneous determination of ambroxal hydrochloride and salbutamol sulphate in combined dosage form i.e. tablets by using distilled water as a solvent. The method was further validated by ICH guidelines. The proposed third order derivative method involves the measurement of absorbance of one drug at zero crossing point of other; hence wavelengths 215 nm and 233.8 nm were selected for the estimation of ambroxal hydrochloride and salbutamol sulphate respectively. The linearity of the proposed method was found in the concentration range of 1 to 10 μg /ml (r2= 0.9989) for ambroxal hydrochloride and 1 to 16 μg /ml (r2= 0.9971) for salbutamol sulphate respectively. The percentage mean recovery was found to be 99.981 % for ambroxal hydrochloride and 100.02 % for salbutamol sulphate respectively. The method was also statistically validated for its linearity, accuracy and precision. Both intra and inter day variations showed less percentage (%) RSD values indicating high grade of precision of this method.
