CHROMATOGRAPHIC DETERMINATION OF CAFFEINE IN PHARMACEUTICAL FORMULATIONS USING MICELLAR MOBILE PHASES

An HPLC procedure is described for the determination of caffeine in ph armaceutical preparations. A Spherisorb octadecylsilane ODS-2 C-18 ana lytical column and spectrophotometric detection at 273 nm were used. T he chromatographic behaviour of caffeine with different micellar eluen ts containing sodium dodecyl sulphate (SDS) is described. The determin ation of caffeine in pharmaceutical preparations was performed by use of a mobile phase containing 0.05 M sodium dodecylsulphate (SDS) and 1 .5 % propanol at pH 7. At a 6.0 mu g mL(-1) concentration level the pe ak area and peak height repeatability were 2.6 and 2.4 %, respectively . The application of the proposed method to the analysis of five pharm aceutical formulations, using peak heights as the dependent variable, gave recoveries between 85 and 104 % of the values declared by the man ufacturers. The proposed procedure for the determination of caffeine i s rapid (15 min per sample), reliable and free from interferences.