Quantitation of olanzapine in tablets by HPLC, CZE, derivative spectrometry and linear voltammetry

Four analytical methods have been developed for the quality control of phar maceutical formulations containing the novel antipsychotic drug, olanzapine : high performance liquid chromatography (HPLC), capillary zone electrophor esis (CZE), derivative spectrometry and linear voltammetry. All methods req uire only a simple extraction procedure of olanzapine from the tablets befo re analysis. HPLC with ultraviolet detection at 260 nm is carried out with a C8 column and a mobile phase constituted of acetonitrile and aqueous tetr amethylammonium perchlorate. CZE is performed in an uncoated capillary with phosphate buffer, pH 3.0, as the background electrolyte, with UV detection at 214 nm. Spectrophotometry uses the derivative of the spectrum at 298 nm . In linear voltammetric method (LSV) the current intensity of the oxidatio n wave at + 495 mV is measured. All methods gave similar results in terms o f precision and accuracy. For HPLC and CZE, repeatability and intermediate precision, expressed by the RSD was better than 1.8%. The accuracy, resulti ng from recovery experiments, was between 99.9 and 101.1%. Spectrometry and voltammetry Save slightly higher RSD values (up to 2.9%) and a larger vari ation of the accuracy (the recovery was between 97.8 and 102.6%). However, the requirements for quantitative analysis are fulfilled for all methods. ( C) 2000 Elsevier Science B.V. All rights reserved.