Determination of impurities in Nifedipine, Clofibrate, Atenolol, timolol, propranolol and Ranitidne by HPLC

Abstract

In this work the impurities of the title compounds were investigated by HPLC. the samples were collected from drug stores and the Bulk Chemicals were obtained from manufacturers. The samples were dissolved in suitable solvents before analysis. The Detector was UV and the Cloumn was bondapack Cjg(30 cmx3.9 mm). In the case of timolol the colum was microbondapack CN.
The impurity in nifedipine was 2, 6 - dimethyl -3,5-dicarbomethoxy - 4-Nitrosophenylpyridine; in clofibrate was para - chlorophenol; in atenollol was p - hydroxyphenylacetamide; in ranitidine was ranitidine - N-oxide, 2,2-dimethylthiol - nitroethene and two unknown compounds. In timolol and propranolol one impurity was detected. The amount of impurities in all compounds were in acceptable range.