Simultaneous spectrophotometric determination of phenilpropanolamine HCL, caffeine and diazepam in tablets

A rapid, reliable and specitic UV spectrophotometric method was developed to determine Phenilpropanolamine Hydrochloride (I), Caffeine (II) and Diazepam (III) formulated in tablets. This method was validated and compared with a liquid chromatography (LC) procedure used for the simultaneous quantitative analysis of the drugs. The established linearity ranges by both methods for compounds I, II and III were 0.36-0.88, 0.012-0.028 and 0.036-0.084 mg/ml, respectively. The correlation coefficients by HPLC were r(I)(2) = 0.997, r(II)(2) = 0.999, r(III)(2) = 0.999 and by the UV spectrophotometric method were r(I)(2) = 0. 998, r(II)(2) = 0 996, r(III)(2) = 0.999. LC and UV methods showed precision and accuracy. As regards precision, LC showed CV values range of 0.2-0.9 and UV 0. 15-0.72. On the other hand, accuracy was obtained with CV values range of 0.1-1.8 and 0.32-1.11 for LC and UV, respectively. The recoveries of I, II and III were > 98.04% for both methods over the linear range. The UV and HPLC methods have been successfully used to determine the I, II and III content in tablets of different origin. (C) 2002 Elsevier Science B.V. All rights reserved.