Simultaneous HPLC determination of nitrendipine and impurities of the process of synthesis

A method has been developed for separation of nitrendipine and its impurities of reaction partners and side reaction products by high-performance liquid chromatographic method on a RP-ls column and detection at 238 nm. The mobile phase composition that provided an acceptable nitrendipine resolution, in large excess and possible impurities, in a short elution time, is methanol:water (70:30) and pH 3. Linearity (r greater than or equal to 0.999), reproducibility (RSD = 0.8-1.4%), determination limit (0.5 2%,) and recovery (99.8-102.3) were validated and found to be satisfactory. This method enables monitoring of the process of synthesis, as well as the choice of the synthetic design. (C) 2001 Elsevier Science B.V. All rights reserved.