Preparation, Optimization, and Evaluation of Hyaluronic Acid-Based Hydrogel Loaded with Miconazole Self-Nanoemulsion for the Treatment of Oral Thrush

Miconazole nitrate (MZ) is a BCS class II antifungal poorly water-soluble drug with limited dissolution properties and gastrointestinal side effects. Self-nanoemulsifying delivery system-based gel of MZ can improve both solubility and oral mucosal absorption with enhanced antifungal activity. The study aims to formulate MZ self-nanoemulsion (MZ-NE) and combine it within hyaluronic acid-based gel. MZ solubility in various oils, surfactants, and cosurfactant used in NE formulations were evaluated. Mixture design was implemented to optimize the levels of NE components as a formulation variable to study their effects on the mean globule size and antifungal inhibition zones. Further, the optimized MZ-NE was loaded into a hyaluronic acid gel base. Rheological behavior of the prepared gel was assessed. Ex vivo permeability of optimized formulation across buccal mucous of sheep and inhibition against Candida albicans were examined. Mixture design was used to optimize the composition of MZ-NE formulation as 22, 67, and 10% for clove oil, Labrasol, and propylene glycol, respectively. The optimized formulation indicated globule size of 113 nm with 29 mm inhibition zone. Pseudoplastic flow with thixotropic behavior was observed, which is desirable for oral gels. The optimized formulation exhibited higher ex vivo skin permeability and enhanced antifungal activity by 1.85 and 2.179, respectively, compared to MZ-SNEDDS, and by 1.52 and 1.72 folds, respectively, compared to marketed gel. Optimized MZ-NE hyaluronic acid-based oral gel demonstrated better antifungal activity, indicating its potential in oral thrush pharmacotherapy.