Development and characterization of solid lipid microparticles containing vitamin C for topical and cosmetic use

Solid lipid microparticles (SLMs), combined with the advantages of double emulsions (W/O/W) and water‐in‐oil micro emulsions, are developed for transdermal administration. A modified one‐step emulsification method was introduced, which made the industrial production of SLMs easier. Variables involved in preparation that may affect the solubility, stability, and entrapment efficiency of SLMs were investigated. With vitamin C as a model active, the advantages of SLMs in transdermal administration were studied further. Vitamin C, encapsulated by SLMs, exhibited an enhanced storage stability up to 1 month under 25°C and a sustained releasing profile over 24 h. Furthermore, the SLMs was very helpful in delivering vitamin C molecules into skin through stratum corneum. The result showed 5.52‐fold (p