ABSTRACT:
This study focuses on the development and evaluation of a bigel system incorporating mupirocin-loaded solid lipid nanoparticles (SLNs) for topical antibacterial application. SLNs were prepared using the solvent diffusion–evaporation method, employing Phospholipon 90G as the lipid and Poloxamer 407 as the surfactant. A 3² full factorial design comprising nine experimental combinations was employed to investigate the effects of lipid and surfactant concentrations on particle size, entrapment efficiency, and zeta potential. The centre-point formulation was prepared in replicate to assess experimental variability, resulting in a total of 13 experimental batches. The optimized SLN formulation exhibited a particle size of 120.12 nm, entrapment efficiency of 86.57%, and zeta potential of -22.5 mV. The optimized SLNs were incorporated into a bigel system comprising hydrogel and oleogel phases. The prepared bigel was evaluated for pH, viscosity, spreadability, homogeneity, in-vitro drug release, skin irritation potential, and antibacterial activity. The optimized bigel exhibited suitable physicochemical characteristics, with a viscosity of 4929 cps and spreadability of 16.31 g·cm/sec. In-vitro drug-release studies demonstrated a sustained-release profile, with 55.5% drug release observed after 14 h. The formulation exhibited a 16 mm zone of inhibition against Staphylococcus aureus, compared with 17 mm for the marketed mupirocin formulation. The HET-CAM assay showed no observable signs of irritation, indicating good topical tolerability. Overall, the optimized mupirocin SLN-loaded bigel demonstrated favorable physicochemical characteristics, sustained in-vitro drug release, and antibacterial activity, indicating its potential as a topical delivery system for localized treatment of bacterial skin infections.