5- Normal Phase High Performance Liquid Chromatographic Determination of Chlorphenoxamine Hydrochloride, Caffeine and 8-chlorotheophylline

An isocratic, rapid and reproducible high performance liquid chromatographic (HPLC) method for quantitative determination of chlorphenoxamine hydrochloride (CPHX), caffeine (CAFF) and 8-chlorotheophylline (CTHE) has been adopted. The optimal conditions for separation and quantitative determination of these compounds were a normal phase mode chromatography and isocratic elution at ambient temperature. A silica column and a mobile phase consisted of ethyl acetate methanol (50:50 v/v) / triethylamine pH 9, have been used at a flow rate of 1 ml min. The components of column effluent were monitored by UV detector at 254 nm. The retention times (tR) for CPHX, CAFF and CTHE were 6.15, 4.23 and 2.97 min, respectively. The linearity range for CPHX, CAFF and CTHE were 37.5 725 μg ml, 0.75 48 μg ml and 0.1 40 μg ml, respectively. The mean accuracy ± % RSD for CPHX, CAFF and CTHE were 100.06 ± 0.47, 99.43 ± 0.60 and 100.65 ± 1.25, respectively. The results obtained by the recovery studies indicated suitable validation parameters. The proposed method showed good efficiency for simultaneous quantitative determination of CPHX, CAFF and CTHE in bulk and tablet dosage from. Statistical comparison between the results obtained by the proposed method and those obtained by the selected official methods for these drugs was carried out and no significant differences were found.