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.

Keywords:

• degradation impurity
• Gefitinib
• HPLC
• oxidative stress
• photo diode array
• validation

Acknowledgments

We thank Dr. Anil Kush, CEO, for his keen interest and support in this study; as well as Dr. Chandregowda Venkateshappa and Mr. Raghava Thimmappa for helpful discussions.