The electrochemical behaviour of chlorpromazine hydrochloride (CPZ-HCI) in sulphuric acid was investigated voltammetrically using ruthenium electrodes and it was subsequently determined by the same method. From the recorded voltammograms it was concluded that CPZ-HCI can be determined in the concentration range 2 x 10(-4)-8 x 10(-4) M (71-284. 3 micrograms ml-1). The proposed voltammetric method was applied to the determination of CPZ-HCI in tablets used for neuroleptic purposes in Turkey; the amount of effective compound was found to be within the ranges given for a pharmacopoeial procedure.

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Quantitative determination of clopidogrel (CLP) was carried out by using zero-order and derivative ultraviolet (UV) spectroscopy. Calibration curves for CLP in 0.1N HCl between 0.1-0.8 mM (42-336 µg/mL) concentration range were obtained by the measurements at 267.5, 271.5 and 279.3 nm for first derivative, at 269.5, 273.4, 277.3 nm for second derivative and at 268.1, 271.3, 275.6 nm for third derivative UV spectrophotometry, respectively. In application, 270 nm in zero-order UV spectrophotometry, 279.3 nm in first derivative UV spectrophotometry, 269.5 nm in second derivative UV spectrophotometry and 275.6 nm in third derivative UV spectrophotometry were selected by their lowest relative standard deviation values in the validation studies. Mean recoveries and the relative standard deviations of the methods were found as 98.7 % and 1.90 % in zero-order UV spectrophotometry, 97.5 % and 0.76 % in first derivative UV spectrophotometry, 99.6 % and 1.25 % in second derivative UV spectrophotometry, 99.5 % and 1.15 % in third derivative UV spectrophotometry, respectively. In this study, the values of limit of detection and limit of quantitation were calculated at selected λ values as 0.01mM and 0.03 mM for zero-order (λ 270 nm), 0.02 mM and 0.07 mM for first derivative (λ 279.3 nm), second derivative (λ 269.5 nm), third derivative (λ 275.6 nm) UV spectrophotometry, respectively. The proposed methods were applied to the determination of CLP in bulk and tablets. The results were compared statistically with each other and high performance liquid chromatography (HPLC) procedure. The differences were not significant. In HPLC method, an isocratic system consisted of a Nova-Pak ® C18 analytical column and a mobile phase composed of pH 8 phosphate buffer : acetonitrile (30:70, v/v) at a flow rate 0.8 mL/min was used for the optimal chromatographic separation using UV detection at 210 nm. Applying HPLC method, linearity was observed in the concentration range from 1.26 to 7.55 µg/mL for CLP with a correlation coefficient 0.999. The values of the limit of detection and limit of quantitation were calculated as 0.29 µg/mL and 0.96 µg/mL, respectively. Synthetic samples were analyzed and mean recoveries and the relative standard deviations were found as 99.95 % and 0.40 % in HPLC. The spectrophotometric methods presented in this study can be used accurate, simple, economic and practical in the determination of CLP in tablets. The procedures do not require any separation step. The mean recoveries were found satisfactory in the methods. These methods also give repeatable results. Proposed methods could usefully be applied to routine quality control of tablets containing CLP. No interference was observed from common excipients in pharmaceutical formulations.