Stability-indicating high-performance liquid chromatographic assay for alpha-methyldopa in sustained-release capsules.
A stability-indicating high-performance liquid chromatographic assay has been developed for the analysis of alpha-methyldopa (MD) in sustained-release capsules and in the presence of MD decomposition products and an MD industrial impurity, 3-O-methyl-methyldopa (MMD). The method utilizes reversed-phase chromatography (cyano-bonded column), an acidic mobile phase containing sodium heptanesulphonate as ion-pairing reagent and UV detection. Detector responses were linear in the ranges 0.5-200 microgram/ml for MD and 0.2-100 microgram/ml for MMD. The mean recoveries of MD from authentic sample and sustained-release capsules were 100.09 +/- 0.38 and 100.38 +/- 0.46%, respectively. The recovery of MD added to degraded MD, were 99.69% by the proposed method and 153.13% by the US Pharmacopeial (USP) spectrophotometric method. The method is sensitive, accurate and rapid and can be used in routine analysis for MD.
Metwally M el-S
Department of Analytical Chemistry, Faculty of Pharmacy, Mansoura University, Egypt.
D002214:Capsules; D002851:Chromatography, High Pressure Liquid; D003692:Delayed-Action Preparations / Q000592:standards*; D004355:Drug Stability; D008750:Methyldopa / Q000031:analogs & derivatives / Q000032:analysis / Q000592:standards*; D011786:Quality Control
D002214:Capsules; D003692:Delayed-Action Preparations; D008750:Methyldopa; C021712:3-O-methylmethyldopa