Non-ionic surfactant vesicles as novel delivery systems for sulfasalazine: Evaluation of the physicochemical and cytotoxic properties

•Encapsulation of sulfasalazine drug in micellar/niosomal vesicles.•The sulfasalazine micellar/niosomal vesicles showed sustainable release behaviors.•Cytotoxicity of sulfasalazine-loaded vesicles was confirmed on MDA-MB-231, MCF-7, and HeLa cell lines. Sulfasalazine (SSZ) is a sulfa drug that is used to treat various forms of arthritis and is known for its ability to induce apoptosis in T lymphocytes and cancer cells. To enhance its solubility and efficacy, we encapsulated SSZ within a micellar/niosomal formulation. The micellar/niosomal formulation was prepared using an amphiphilic self-assembly method involving squalene (S) and tween 80 (T8) for the first time. The encapsulation and release of SSZ from the nanocarrier was characterized. The percent encapsulation efficiency of SSZ was 99.5 ± 0.2 %, 90.5 ± 0.5 %, and 80.5 ± 0.8 % for the 5:100, 7.5:100, and 10:100 (w/w) ratios of SSZ:total weight of ST8 micellar/niosomal vesicles (ST8MNVs), respectively. A higher loading of 20:100 (w/w) led to SSZ diffusion from the vesicular systems within 24 h. The cytotoxic activity of the SSZ-encapsulated ST8MNVs was evaluated against different cancer cell lines. Encapsulation and the use of the nanoformulations improved the effectiveness of SSZ in promoting apoptosis in MDA-MB-231, MCF-7, and HeLa cell lines, by reducing the IC50 value by at least five folds. The high loading and encapsulation of SSZ within the micellar/niosomal formulation together with its greater water solubility enhanced the bioavailability of the drug, improving its potential for biomedical and therapeutic applications. [Display omitted]