Development and Characterization of A Saffron-based Sneeds Formulation with Cytotoxicity Evaluation on Normal Cells

Abstract

Background: Saffron exhibits therapeutic activities such as antioxidant and antiinflammatory effects. However, its key compounds, crocin and safranal, have limited solubility and stability, which may be improved using a SelfNanoemulsifying Drug Delivery System (SNEDDS) to enhance their stability and solubility. Objective: To develop and characterize saffron SNEDDS to improvove solubility and stability of its bioactive compounds. Methods: Saffron stigmas are extracted using ultrasound-assisted extraction with 58.58% ethanol-water. Castor oil represents the oil phase, Tween 80 is the surfactant, while propylene glycol is used as a cosurfactant. Formulations are optimized by adjusting component ratios. Cytotoxicity is assessed on Vero cells treated with saffron-loaded SNEDDS (100–2000 ppm) using the MTT assay. Evaluated parameters include extract yield, droplet size, PDI, zeta potential, loading capacity, in vitro drug release, and stability. IC₅₀ was calculated to determine cytotoxicity. Results: The extract met Category I quality with a 55.8% yield. Crocin is most soluble in propylene glycol and Tween 80, while safranal and picrocrocin dissolved best in castor oil. The solubility profile supported a high Smix-to-oil ratio. The optimized SNEDDS (Smix 4:1, Smix:oil 9:1) produced droplets <200 nm with PDI ≤0.3, zeta potential ~–32 mV, and encapsulation efficiency >80%. In vitro release followed first-order (crocin and picrocrocin) and Higuchi (safranal) models. After one month, the formulation remains stable in appearance, droplet size, and PDI, though zeta potential stayed slightly below ideal. IC₅₀ is found 0.275 µg/mL, classifying it as highly toxic. Conclusion: The saffron-loaded SNEDDS showed promising physicochemical properties and stability, but its high cytotoxicity limits potential for human use.