Development of assay method for clotrimazole as a sustained release solid dosage form / Sofiyyah Sa’adon

Sustained-release drug delivery systems allow the antifungal agent to reside at the sites of infection for a prolonged period; hence the systems are ideal to be applied topically in order to achieve desirable therapeutic effect. A simple, sensitive, rapid and reproducible assay method has been developed for determination of the antifungal drug, clotrimazole, when it is incorporated with sodium carboxymethylcellulose as the polymer for sustained-release solid dosage form. Chromatographic method was applied by using high performance liquid chromatography (HPLC) equipped with reversed phase octadecylsilica (ODS) C l8 column. The compound was separated with the mobile phase comprised of acetonitrile and 25 mM disodium hydrogen phosphate anhydrous (65:35, v/v) adjusted to pH 8 with o- phosphoric acid. Analysis was run at a flow rate of 1.0 ml/min and the column effluent was monitored at a wavelength of 220 nm. The calibration graph was linear over the concentration range of 10-100 pg/ml with the retention time of 3.74 min. The correlation coefficient of the calibration curves were always >0.999, while the within- day and between-day coefficient of variation were all less than 1%. The developed method has been successfully applied for the determination of clotrimazole from its polymer.