STABILITY-INDICATING CAPILLARY ELECTROPHORESIS METHOD WITH PHOTODIODE ARRAY DETECTOR FOR DETERMINATION OF LENALIDOMIDE IN PHARMACEUTICAL PREPARATION

This study describes, for the first time, the development and validation of a simple, sensitive and accurate stability-indicating capillary electrophoresis method with photodiode array detector for the determination of lenalidomide (LEN) in its bulk form and pharmaceutical preparation. Metoclopramide was used as the internal standard. Electrophoretic separation was achieved in a deactivated fused silica capillary (52 cm effective length x 75 mu m internal diameter) maintained at 22 degrees C, by a background electrolyte solution consisting of phosphate buffer solution (20 mM, pH 7.1): methanol (90: 10, v/v). The samples were injected by pressure at the anodic side at 20 mbar for 25 seconds, and the separation voltage was 30 kV. The detection wavelength was set at 210 nm. LEN was subjected to different accelerated stress conditions. The degradation products, if any, were well resolved from the intact drug with significantly different migration time values. The limit of detection and limit of quantitation were 0.25 and 0.80 mu g mL(-1), respectively. The intra- and inter-assay precisions were satisfactory; the relative standard deviations did not exceed 0.59%. The accuracy of the method was proved; the mean recovery of LEN was 98.53 +/- 100.80 (+/- 0.25 - 0.59%). The proposed method was successfully applied for the determination of LEN in bulk and capsules; the label claim percentage was 99.52 +/- 0.43%. The results demonstrated that the method would have a great value when applied in quality control and stability studies for LEN.