Simultaneous determination of some multicomponent dosage forms by quantitative thin layer chromatography densitometric method

In this study, simultaneous determination of naproxen with diflunisal (mixture I), paracetamol with chlorzoxazone (mixture II) and chlorphenoxamine hydrochloride with 8-chlorotheophylline and caffeine (mixture III) in multicomponent mixtures was conducted by a thin layer chromatography-densitometric method. The mobile phase ethyl acetate: methanol: ammonia 25% (85:15:5 v/v) was used for the separation of the components of mixtures (I) and (II) with R-f values of 0.16 for naproxen, 0.4 for diflunisal, 0.77 for paracetamol and 0.32 for chlorzoxazone. Efficient separation of the components of mixture (III) was attained using ethyl acetate as mobile phase with R-f values of 0.12, 0.62 and 0.42 for chlorphenoxamine hydrochloride, 8-chlorotheophylline and caffeine, respectively. Linearity ranges, mean recoveries and relative standard deviations in calibration graphs of the proposed method were calculated. The method has been successfully applied to pharmaceutical formulations, sugar-coated tablets, capsules and suppositories. The results obtained were statistically compared with those obtained by applying the reported alternate methods. (C) 1999 Elsevier Science B.V. All rights reserved.