Solid Self-nanoemulsifying Drug Delivery System (S-SNEDDS) for Improved Solubility of Enzalutamide

Abstract

The objective of this study was to develop a novel enzalutamide-loaded solidified self-nanoemulsifying drug delivery system formulation with enhanced solubility and dissolution rate. Various oil and surfactant were screened, then Medium Chain Triglyceride oil and Polysorbate 80 and Labrafil M2125CS were selected as oil and a surfactant. Pseudoternary phase diagram was constructed to detect the nanoemulsion zone. Among the SNEDDS formulations tested, SNEDDS consisted of MCT oil (oil), Polysorbate 80 (surfactant) and Labrafil M2125CS (co-surfactant) at a weight ratio of 20:70:10. The SNEDDS produced the emulsion droplet size 18.66±0.88 nm. Spray drying technique was used to convert the selected enzalutamide-loaded SNEDDS into solid SNEDDS with inert carrier such as silicon dioxide. Enzlautamide-loaded solid SNEDDS was characterized by scanning electron microscopy, transmission electron microscopy, powder X-ray diffractometry, dynamic light scattering, saturation solubility and in vitro dissolution study. The S-SNEDDS produced an emulsion droplet size of 15.37±0.49 nm and there was no change in particle size between with or without drug. SEM and PXRD results suggested that enzalutamide existed in amorphous form in enzalutamide-loaded solid SNEDDS. In addition, enzalutamide-loaded solid SNEDDS increased saturation solubility 42-fold and dissolution rates 23- fold compared to crystalline enzalutamide. Therefore, the solid SNEDDS could be a potential nano-sized drug delivery system for poorly water-soluble drug enzalutamide.