Rapid and simple stability indicating HPLC method for the determination of cilazapril in pure substance and pharmaceutical formulation in comparison with classic and derivative spectrophotometric methods.

The present study describes development and subsequent validation of high performance liquid chromatographic method (HPLC) in comparison with spectrophotometric methods (classic, first, second and third order derivative) for determination of pure cilazapril in substance and pharmaceutical preparation. The main aim of this study was to find the method suitable not only for determination of cilazapril, but additionally useful in degradation kinetic study. Only the HPLC method is stability indicating. The HPLC method utilizes LiChroCART 250-4 HPLC-Cartridge, LiChrospher 100 RP-18 (5 μm) column, at ambient temperature, eluted at the flow rate 1.0 mL/min. The mobile phase consists of acetonitrile, methanol and phosphate buffer (pH 2.0) (60:10:30, v/v/v). Wavelength of detection is set at 212 nm. Benzocaine is used as an internal standard. The second and third order derivative spectrophotometric methods can be applied for the cilazapril analysis in substance and tablet, but not for stability evaluation (the lack of selectivity towards degradation product).