Title: DEVELOPMENT AND VALIDATION OF NOVEL ANALYTICAL METHOD FOR THE SIMULTANEOUS ESTIMATION OF MELATONIN AND ZOLPIDEM TARTRATE IN PHARMACEUTICAL DOSAGE FORMS BY USING RP-HPLC TECHNIQUE
Author(s): Nagaraju*, G. Indira Priyadarshini, P. Swathi, and P. Seetharamaiah
A simple, accurate, rapid and precise isocratic reversed-phase high-performance liquid chromatographic method has been developed and validated for simultaneous determination of melatonin and zolpidem tartrate in tablets. The chromatographic separation was carried out on C18 ODS Hypersil -(250X4.6mm, 5µ) with a mixture of mixed phosphate buffer : acetonitrile (55:45%v/v) as a mobile phase at a flow rate of 1.0 mL/min. UV detection was performed at 265 nm. The retention times were 2.517 and 3.630 min for melatonin and zolpidem tartrate respectively. Calibration plots were linear (r2=0.999) over the concentration range of 6-42 µg/mL for melatonin and 10-70 µg/mL for zolpidem tartrate. The method was validated for accuracy, precision, specificity, linearity and sensitivity. The proposed method was successfully used for quantitative analysis of tablets. No interference from any component of pharmaceutical dosage form was observed. Validation studies revealed that method is specific, rapid, reliable, and reproducible. The high recovery and low relative standard deviation confirm the suitability of the method for routine determination of melatonin and zolpidem tartrate in bulk and tablet dosage form.
Keywords: Melatonin, Zolpidem tartrate, RP-HPLC, Tablets.