Response Surface Methodology-Assisted Development of a Sustainable and High Throughput Microwell Spectrophotometric Method for the Quantitation of Gefitinib: Application to Analysis of Tablets and Content Uniformity Testing
Reem M. Abuhejail, Nada S. Al-Theyab, Rashed N. Herqash, Nourah Z. Alzoman, Ibrahim A. DarwishIntroduction:
Gefitinib (GEF), an epidermal growth factor receptor tyrosine kinase inhibitor, is widely used for treating non-small cell lung cancer. However, existing pharmaceutical quality control methods for GEF are often limited in sustainability, efficiency, and throughput.
Methods:
This study presents an optimized, eco-friendly, and high-throughput microwell-based spectrophotometric method (MW-SPM) for the quantification of GEF in bulk drug and pharmaceutical tablet formulations. The method utilizes the formation of a charge-transfer complex (CTC) between GEF and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in a 96-well microplate, with absorbance measurements obtained via a microplate reader. To ensure robustness and reliability, the method was optimized using response surface methodology (RSM), and its greenness was assessed using the GAPI and AGREE metrics. Computational studies further elucidated the interaction mechanism and charge distribution, providing a theoretical foundation for the proposed method.
Results:
The MW-SPM method facilitated the formation of a stable 1:1 CTC with GEF, exhibiting excellent linearity over the range of 2–200 µg/well with a quantitation limit of 4.5 µg/well. This approach was successfully applied for GEF quantification in commercial tablet formulations, ensuring content uniformity and demonstrating accuracy and precision. Computational analysis confirmed the key interaction sites and provided mechanistic insights into CTC formation.
Discussion:
The MW-SPM method demonstrated high sensitivity, precision, and selectivity for gefitinib analysis via DDQ-based charge-transfer complexation. It met ICH validation criteria, showed comparable performance to HPLC, and aligned with green chemistry principles despite DDQ's toxicity.
Conclusion:
The developed MW-SPM method offers a rapid, sustainable, and high-throughput alternative for GEF quality control, providing greater efficiency, reagent economy, and environmental benefits compared to traditional techniques. Its simplicity, robustness, and applicability to routine pharmaceutical analysis make it a valuable tool for the industry, contributing to greener and more efficient drug quality assessment.