Physicochemical and safety characteristics of novel microstructured lipid-based drug delivery system encapsulating miconazole nitrate

This study was designed to investigate an intravaginal drug delivery system based on biocompatible phytolipids [Softisan® 154 (SF) (hydrogenated palm oil) and super-refined sunseed oil (SO)] and polyethylene glycol (PEG)-4000 for improved physicochemical performance and safe delivery of miconazole nitrate (MN). Lipid matrices (LMs) consisting of optimized 1:9 blend of SO and SF with increasing amounts of PEG-4000 (0, 10, 20, 40 % w/w) were employed to formulate MN-loaded solid lipid microparticles (SLMs) by melt-homogenization. The SLMs were evaluated in terms of encapsulation efficiency (EE), loading capacity (LC), particle size, morphology, tolerability in female rabbits and stability. Results showed that SLMs based on SO:SF (1:9) and PEG-4000 (40 %w/w) gave highest EE (88.05%) and LC (25.00 g of MN per 100 g of lipid). This optimized formulation (DM) had the least particle size, mostly spherical microparticles. Moreover, the formulation was stable and histopathologically safe. This study has shown that the developed microstructured lipid-based formulation could be employed for improved physicochemical performance and safe intravaginal delivery of miconazole nitrate.Keywords: Miconazole nitrate, Softisan® 154, Intravaginal drug delivery, Physicochemical performance, vaginal tolerance test (VTT), Biocompatible phytolipid