Efficient Co‐Loading of Paclitaxel and Gefitinib in <scp>PLGA</scp> Nanoparticles: Use of Design of Experiments ( <scp>DoE</scp> ) Approach for Enhanced Efficacy Against <scp>MCF</scp> ‐7/ <scp>MCF</scp> ‐ <scp>7ADR</scp> Cells

ABSTRACT In this study co‐loading of paclitaxel and gefitinib in PLGA nanoparticles for breast cancer treatment has been explored as a strategy to overcome limitations of using the drug alone. Combination index studies using Chou–Talay method were used to identify the optimal ratio of both drugs that showed the maximum synergistic effect. Using the design of experiment ( DoE ) methodology, PLGA nanoparticles co‐loaded with paclitaxel and gefitinib were formulated and optimized. Further characterization and cell line evaluations were performed. The mean particle size obtained was 169.79 nm, and entrapment efficiencies of PTX and GEF were 89.17% and 76.89% (w/w), respectively. Formulated co‐loaded nanoparticles had enhanced cellular uptake and lower IC 50 in MCF ‐7 and drug‐resistant MCF ‐7/ ADR cells.