GLC assay of fenclorac in human plasma.

A simple, sensitive GLC assay for fenclorac is described. Plasma proteins were precipitated with methanol, and the methanolic extract was refluxed with hydrochloric acid to form the methyl esters of fenclorac and the internal standard. The esters were purified by partitioning into benzene.

Characterization of impurities in sulfasalazine.

The chemical structures of four impurities isolated from sulfasalazine were determined. Three impurities are the by-products of the reaction process in drug synthesis, i.e.

Hydrolytic degradation of 2,6-dichlorobenzylthiopseudourea hydrochloride.

Degradation of 2,6-dichlorobenzylthiopseudourea hydrochloride was followed in basic medium (pH 7.5) to isolate and characterize all possible degradation products. IR, Raman, and NMR spectroscopy, TLC, and elemental analysis were used to identify the products.