Efavirenz (EFV)

A novel, simple, rapid and stability-indicating reversed-phase ultra performance liquid chromatographic and mass spectrometric method was developed and subsequently validated for quantitation of Efavirenz (EFV) from drug substance matrix. The separation was achieved in 2.5 minutes on Waters ACQUITY UPLC BEH C18 (50 x 2.1) mm, 1.7µm column in isocratic mode with flow rate 0.4 mL/min. Mobile phase used was 0.01 M ammonium acetate buffer pH 7.5 and acetonitrile in ratio 50:50 v/v. Detection was carried out at the maximum wavelength of 247 nm using a photodiode array detector. The retention time of Efavirenz was found 1.8 minutes. Specificity of the method was established on drug substance by hydrolytic and oxidative stress conditions. Validation of analytical method was carried out as per the current ICH guidelines for linearity, recovery, precision, limit of detection, limit of quantification and robustness parameters.

  A simple, specific, accurate and precise First order derivative UV Spectrophptometry method was developed and validated for the estimation of Efavirenz in bulk and pharmaceutical dosage forms. The stock solution was prepared by weighing 100 mg of standard EFV in 100 ml volumetric flask with methanol and water (50:50) (Stock solution I). The final stock solution was made to produce 100µg/ml with methanol and water (50:50).Further dilutions were prepared as per procedure. The first derivative amplitude at 238.50 nm was selected for the assay. The linearity was found in the concentration range of 3-18 µg/ml. The Correlation coefficient was 0.999. The regression equation was found to be y = 0.038 x - 0.001. The method was validated for linearity, sensitivity, precision, accuracy and ruggedness. The limit of detection and limit of quantification for estimation of EFV was found to be 0.078µg/ml and 0.236 µg/ml, respectively. Recovery of EFV was found to be in the range of 99.08-99.97 %. Proposed method was successfully applied for the quantitative determination of EFV in bulk and pharmaceutical dosage forms. These methods were tested and validated for various parameters according to ICH guidelines. The proposed methods were successfully applied for the determination of EFV in capsule formulations. This method was successfully applied to the pharmaceutical dosage form and there no interference of capsule excipients was found in recovery study. Key words: Efavirenz (EFV), ICH (International Conference on Harmonization), and UV- Spectrophotometric method.