Combinatorial Therapy of Letrozole and Quercetin Loaded Spanlastics for Enhanced Cytotoxicity Against MCF-7 Breast Cancer Cells

The study investigated the use of letrozole- and quercetin-loaded spanlastics for enhanced cytotoxicity against MCF-7 breast cancer cells. The spanlastics were prepared with different edge activators and evaluated for particle size, surface charge, and encapsulation efficiency. The optimized formulations showed sustained drug release and effective skin permeation. The combination of letrozole and quercetin in spanlastics demonstrated superior in vitro cytotoxicity, cell cycle arrest, and increased reactive oxygen species production compared to individual treatments and soluble free drugs. These findings suggested that the combination therapy could improve breast cancer management through transdermal drug delivery.