Vitamin D-loaded lipid nanoparticles: antioxidant properties, preparation, optimization, and in vitro characterization.

Vitamin D3-loaded lipid nanoparticles (Vit D3-LNP), integrated into an azulene cream, were developed to enhance the topical delivery and stability of Vitamin D3. The LNP was formulated using a lipid mixture and hot homogenization-ultrasonication, with comprehensive characterization revealing a particle size of 153.9 nm, a high zeta potential (-54.3 mV), and a PDI of 0.216, which TEM confirmed. Encapsulation efficiency was high (96.98%), indicating successful incorporation of Vitamin D3 within the lipid matrix. Stability studies revealed the impact of light exposure on Vitamin D3 degradation. In vitro, release, and skin penetration studies using Franz diffusion cells and two-photon microscopy demonstrated enhanced drug permeation and retention in deeper skin layers with the cream formulation. Cell Viability test confirmed high cell viability (~ 80-100%) for both free Vitamin D3 and the LNP formulation; also inflammation test showed a significant reduction in ROS levels with Vitamin D3-LNP treatment. These findings highlight the therapeutic value of LNP in managing conditions like Vitiligo, providing insights into the design of stable, effective Vitamin D3 delivery systems for dermal applications, and offering a promising approach for advanced skin treatments.