Separation and Estimation of Intermediates Formed During Synthesis of Gefitinib via 4-Methylthio-Quinazoline Route Using High Performance Liquid Chromatography

Abstract

γ A simple, fast, and precise high performance liquid chromatographic method was developed for the estimation of seven intermediates formed during the synthesis of gefitinib, an anticancer drug by a patent noninfringing route. Also, one degradation product (gefitinib N-oxide) formed during oxidative stress were analyzed and identified. All these compounds were separated on Inertsil ODS-3 V (250 × 4.6 mm, 5 µm) column using isocratic mobile phase consisting of ammonium acetate (0.05 M)–acetonitrile–methanol (70:25:5, v/v/v) (pH 4.1) at a flow rate of 1 mL/min and detected at 260 nm by a photo diode array (PDA) detector. The developed method was validated for accuracy, precision, linearity, sensitivity, and ruggedness. Linear regression analysis revealed an excellent correlation between peak responses and concentrations (R2 values > 0.995) for the drug and impurities. The proposed HPLC method was applied for estimation of process-related intermediates/impurities in gefitinib bulk drug; the recoveries were in the range 91.09–103.07%. The method was found to be specific, precise, and reliable for estimation of process-related intermediates/impurities and degradation impurities in gefitinib bulk drug. The highlight of this technique is that all the intermediates/impurities of gefitinib could be analyzed with baseline separation and reduced run time.