Effect of Co-Loaded Vitamin D3 on Intravenous Injectable Raloxifene Delivery System

Abstract

Owing to its promising advantages, including improved drug bioavailability and therapeutic efficiency at low doses and frequency, increased patient convenience and compliance, and prolonged storage life, nanomedicine has received heightened attention over conventional pharmaceuticals. Human serum albumin (HSA)-based nanoparticles have been used as drug carriers in injectable formulations, with great success and versatility. In this study, raloxifene and vitamin D3 were co-encapsulated in HSA-based nanoparticles (Ral/VitaD/HSA/PSS NPs) as an intravenously injected pharmaceutical formulation in order to enhance their availability in the body. The lyophilization–hydration method was utilized to develop the Ral/VitaD/HSA/PSS NPs. In addition, the characteristics and stability of the NP and the effect of the co-loading of vitamin D3 on raloxifene release in vitro and in vivo were discussed. The raloxifene and vitamin D3 molecules were successfully encapsulated and well dispersed in an amorphous state within Ral/VitaD/HSA/PSS NPs. The prepared Ral/VitaD/HSA/PSS NPs were lyophilized for long-term storage and were both biocompatible and hemocompatible, enhancing alkaline phosphtase activity in osteoblasts. Delivered via intravenous injection, Ral/VitaD/HSA/PSS NPs addressed the low bioavailability of raloxifene and vitamin D3 caused by oral administration, and improved their compatibility and residence time in the body. Overall, the established raloxifene–vitamin D3-co-loaded NPs may be a potential nanomedicine contender for treating postmenopausal osteoporosis.