Process-guided design of nanoliposomal vitamin D3: formulation, stability and quality by design mapping

The development of aqueous vitamin D₃ supplements remains challenging because the molecule is poorly soluble, chemically fragile, and prone to loss of potency during storage. In this work, we adopted a Quality-by-Design (QbD) strategy to construct a nanoliposomal structure able to protect and deliver vitamin D₃ while maintaining technological simplicity and high tolerability. As a first step, drug-free nanoliposomes were produced using a coaxial-jet mixer and systematically investigated through a Box-Behnken Design. This approach allowed us to identify the critical relationships between phosphatidylcholine concentration, solvent/antisolvent flow rates, and the resulting nanoliposomal architecture, thereby defining a robust design space for nano-vesicle formation. Vitamin D₃ was then introduced into the optimized system to verify process transferability. Encapsulation proved efficient and compatible with the micromixing-driven assembly of nanoliposomes, and the formulation was subsequently subjected to accelerated and real-time stability studies. These experiments revealed a clear hierarchy of stabilizing effects, highlighting the combined protective role of the liposomal bilayer and a carefully balanced antioxidant environment. Building on these findings, the research formulation was further refined into a commercially viable product, described in a dedicated patent, and benchmarked against leading marketed references. The final dispersion exhibited high structural uniformity, stable vitamin retention and manufacturing features consistent with large-scale implementation. Overall, this work demonstrates how a QbD-guided pathway - from mechanistic process mapping to stability-driven optimization and product translation - can yield a high-quality nanoliposomal vitamin D₃ with clear technological and practical advantages.