Development and Validation of a Gas Chromatography Method for Quality Control of Residual Solvents in Azilsartan Bulk Drugs

A new gas chromatographic method for the simultaneous determination of six organic residual solvents (acetonitrile, tetrahydrofuran, ethanol, acetone, 2-propanol and ethyl acetate) in azilsartan bulk drug is described. The chromatographic determination was achieved on an OV-624 capillary column employing programmed temperature within 21 min. The validation was carried out according to International Conference on Harmonization validation guidelines. The method was shown to be specific (no interference in the blank solution), sensitive (Limit of detection can achieve 1.5 mu g/mL), precise (relative standard deviation of repeatability and intermediate precision <= 5.0%), linear (r >= 0.999), accurate (recoveries range from 98.8% to 107.8%) and robust (carrier gas flow from 2.7 to 3.3mL/min, initial oven temperature from 35 degrees C to 45 degrees C, temperature ramping rate from 19 degrees C/min to 21 degrees C/min, final oven temperature from 145 degrees C to 155 degrees C, injector temperature from 190 degrees C to 210 degrees C and detector temperature from 240 degrees C to 260 degrees C did not significantly affect the system suitability, test parameters and peak areas). This extensively validated method has been applied to the determination of residual solvents in real azilsartan bulk samples.