VALIDATED SPECTROPHOTOMETRIC AND SPECTROFLUORIMETRIC METHODS FOR THE DETERMINATION OF PREGABALIN IN ITS PURE AND DOSAGE FORMS USING EOSIN

Mohammed I. Walash, N. El-Enany and H. Askar*

Two sensitive spectrophotometric and spectrofluorimetric methods were developed for determination of pregabalin (PGB) in its pure and pharmaceutical dosage forms. For spectrophotometric method (Method I), absorbance value of a binary complex with eosin was measured at 550 nm at pH 3.5. The absorbance-concentration plot was rectilinear over the range of 4-80 μg mL^-1. For spectrofluorimetric method (Method II), the decreasing in the fluorescence intensity of the native fluorescence of eosin was measured at 544 nm after excitation at 304 nm at the same pH. The fluorescence-concentration plot was rectilinear over the range of 0.05^-1 μg mL^-1. Statistical comparison of the results with those of the reference method indicated that there was no significant difference between the two methods respectively.