ABSTRACT:
Objective: The objective of this study was to develop and validate a single HPLC method, in order to separate and assay three anti-cough drugs pseudoephedrine, dextromethorphan and chlorpheniramine in pharmaceutical forms. This method was practical additional choice in quality control laboratories. Methods: The chromatographic conditions comprised of a classical C8-type stationary phase (250 × 4.6 mm, 5µ ), with a mobile phase consisting of 8.57gr/l ammonium dihydrogen phosphate, Acetonitrile, triethylamine and tetrahydrofuran (66:30:2:2 v/v %) respectively, and apparent pH of 3.5 was adjusted with hydrochloric acid. The flow rate was 1ml/min; column temperature set at 30ºC; injection volume was 20µl and the detection wavelengths was at 264 nm, Results: The method was validated for linearity with correlation coefficients very close to one, accuracy with mean recovery values between 98.0-102.0%, precision with relative standard deviations of the calculated concentrations less than 2.0%, specificity in the presence of degradation products and robustness in the case of little change of some chromatographic conditions. Then it was used successfully to separate a mixture of them and to assay these drugs in syrup pharmaceutical form purchased from Syria. This analyzed pharmaceutical form contains three active ingredient within 100±2 % of stated concentration, within the limits specified by British and USP Pharmacopeia. Conclusion: The results presented in this paper showed that the developed method was simple and practical for the separation and determination of the three anti-cough drugs in syrup pharmaceutical form.