PREPARATIVE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY FOR THE PURIFICATION OF NITRENDIPINE AND ITS DIMETHYL ESTER.

Normal-phase preparative HPLC was applied to the purification of nitrendipine and its dimethyl ester from raw materials. For each separation, the chromatographic conditions were optimized by adjusting the sample size to achieve an efficient purification with a yield of 99% in the shortest time. The contaminating impurities were removed in a single step by preparative chromatography. This work demonstrates how gram quantities of analytically pure materials can be conveniently obtained using preparative HPLC. [ABSTRACT FROM AUTHOR]