Application of a highly sensitive UV-spectrophotometric method for the determination of amitriptyline hydrochloride in pure and dosage forms

A simple, selective, highly sensitive and cost-effective UV-spectrophotometric method is described for the quantitative determination of amitriptyline hydrochloride (AMT) in both pure and in pharmaceutical preparations. The proposed method is based on the measurement of the absorbance of AMT solution in acetonitrile, which shows maximum absorbances at 217 and 242 nm. The system obeyed Beer’s law over the concentration range of 0.0 – 1.0 μg/ml with apparent molar absorptivity of 2.03 × 105 l/mol/cm. The Sandell sensitivity values, limits of detection (LOD) and quantification (LOQ) values have also been reported. The accuracy and precision of the method were evaluated on intra and inter-day basis; the relative error (% RE) and the relative standard deviation (RSD) were < 2.0 %. The method was applied to the determination of AMT in tablets and the results were statistically compared with those of the reference method by Student’st-test and F-test.