SIMULTANEOUS DETERMINATION OF CAFFEINE AND MECLIZINE DIHYDROCHLORIDE IN SUGAR-COATED TABLETS

In this study, simultaneous determination of caffeine and meclizine dihydrochloride in their binary mixture was conducted by two spectrophotometric methods. In the first method, derivative spectrophotometry, the quantification of caffeine and meclizine dihydrochloride was performed by reading the dA/d lambda values at 286.2 nm and 243.4 nm respectively in the first derivative spectra of their mixture in methanol. The relative standard deviation of the method was 0.54 % for caffeine and 0.67 % for meclizine dihydrochloride. In the second, selective precipitation + derivative spectrophotometry, determination of meclizine dihydrochloride was carried out by precipitation with potassium ferricyanide at pH 2 selectively, then measuring the absorbance of its solution in methanol at 420.8 nm, and determination of caffeine was succeeded by reading the dA/d lambda values at 260.6 nm in the first derivative spectra of the remaining solution after precipitation. Relative standard deviation of the method was found to be 0.56 % for caffeine and 1.85 % for meclizine dihydrochloride. These two methods were applied successfully to a sugar-coated tablet containing these drugs.