Optimization of TLC method for separation and determination of ziprasidone and its impurities

Abstract

A thin-layer chromatographic method for simultaneous determination of ziprasidone and its main impurities was developed and validated. Separation of the examined compounds was performed on chromatographic plates precoated with silica gel 60 F-254 and using toluene-methanol-glacial acetic acid, 7.5:0.5:0.5 (v/v/v) as mobile phase. Ascending development mode was performed in the twin-trough chromatographic chamber, which was presaturated with mobile-phase vapors for 15 min. The developed chromatographic plates were dried in air and densitometrically scanned at the wavelengths of 250 and 320 nm. Regression coefficient (r >= 0.992), recovery (94.94-106.70%), limit of quantification of impurities (25 ng band(-1) equivalent to the 0.14% impurity level), and robustness were validated and found satisfactory. The developed method is convenient for quantitative analysis and the purity screening of ziprasidone in pharmaceutical formulations.