SPECTROPHOTOMETRIC DETERMINATION OF METHYLDOPA IN PURE AND PHARMACEUTICAL PREPARATIONS

Methyldopa reacts with barbituric acid to give a red colour having max imum absorbance at 540 nm. The reaction is selective for methyldopa wi th 0.01 mg/ml as visual limit of quantitation and provides a basis for a new spectrophotometric determination. The colour reaction obeys Bee r's Law from 0.1 mg to 2.5 mg/10 ml of methyldopa and the relative sta ndard deviation is 1.1%. The quantitative assessment of tolerable amou nt of other drugs is also studied.