Osimertinib nano-niosomes: surfactant effects, release kinetics, and cytotoxicity studies

Aim: Osimertinib’s clinical application is limited by poor aqueous solubility and systemic toxicity. Nano-niosomal formulations can address these challenges by providing controlled release and enhancing delivery. To develop and systematically evaluate nano-niosomal formulations of osimertinib using different surfactants, focusing on physicochemical characteristics, release kinetics, and cytotoxic activity. Methods: Four niosomal formulations were prepared using Span 60, Tween 60, Pluronic F-127, and Brij 52 (each at a 1:1 cholesterol-to-surfactant ratio). Particle size, zeta potential, and entrapment efficiency were measured. In vitro drug release was analyzed using Franz diffusion cells and fitted to standard kinetic models. Cytotoxicity was assessed by MTT assay in KAIMRC-2, MDA-MB231, and HCT-116 cell lines. Vesicle morphology was visualized by transmission electron microscopy. Results: All nano-niosomal formulations showed nanoscale particle sizes (47–292 nm), negative zeta potentials (−18.7 to −26.5 mV), and high entrapment efficiencies (69.8%–76.2%). Release studies indicated Span 60, Tween 60, and Pluronic F-127 followed diffusion-controlled kinetics (Higuchi/Korsmeyer–Peppas model, R2 up to 0.97), while Brij 52 provided a sustained zero-order release (R2 = 0.98). Compared to free osimertinib, all niosomal systems significantly prolonged release. Cytotoxicity studies demonstrated that all formulations enhanced anti-cancer effects, with Span 60-based niosomes exhibiting the greatest potency across cell lines. Conclusions: Optimized nano-niosomal encapsulation of osimertinib enables sustained and controlled drug release, improved cellular uptake, and enhanced cytotoxicity in vitro. Differences in surfactant composition critically influence formulation performance, supporting the further development of niosomal osimertinib as a promising strategy for oncological drug delivery applications.