Department of Analytical Chemistry, Faculty of Pharmacy, Mansoura University, Egypt.
J Chromatogr. 1991 Jul 19;549(1-2):221-8. doi: 10.1016/s0021-9673(00)91433-x.
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.
已开发出一种稳定性指示高效液相色谱法，用于分析缓释胶囊中的α-甲基多巴（MD），以及在存在MD分解产物和MD工业杂质3-O-甲基-甲基多巴（MMD）的情况下进行分析。该方法采用反相色谱法（氰基键合柱），以含有庚烷磺酸钠作为离子对试剂的酸性流动相和紫外检测。MD的检测响应在0.5-200微克/毫升范围内呈线性，MMD的检测响应在0.2-100微克/毫升范围内呈线性。从真实样品和缓释胶囊中回收MD的平均回收率分别为100.09±0.38%和100.38±0.46%。添加到降解MD中的MD回收率，用所提出的方法为99.69%，用美国药典（USP）分光光度法为153.13%。该方法灵敏、准确、快速，可用于MD的常规分析。
