RESUMEN
Objective: Solid lipid nanoparticles (SLNs) are at the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery and research. The aim of this study was to develop and characterize SLNs formulae of Terbinafine HCl (TFH) for topical drug delivery applications. Methods: SLNs were prepared using the solvent injection technique. Glyceryl Monostearate (GMS) served as the lipid base. Three stabilizers; Tween 80, Cremophor RH40, and Poloxamer 188, were used. The effect of stabilizer type and concentration, as well as the lipid concentration, were studied, factorial design of 32*21was applied. The prepared SLNs were characterized regarding their particle size, zeta potential, polydispersity index (PDI), entrapment efficiency percent (EE %), and physicochemical stability. The selected formulae were subjected to further investigations such as morphological studies, in vitro release studies, and Infrared (IR) spectroscopy. They were compared with the marketed cream Lamifen® in term of their antifungal activity against Candida albicans. Results: Lipid concentration, together with the type and concentration of stabilizer, appeared to be the main cornerstones which affect the formation of SLNs. Smaller particle size was observed when increasing the stabilizer concentration and decreasing the lipid concentration. Higher EE% was observed when increasing both the stabilizer and the lipid concentrations. Formulae (F6, F12 andF19) were selected as the most suitable SLNs with optimum particle size of 480.2±18.89, 458.6±12.45 and 246.7±10.5 nm, respectively as well as the highest EE% of 87.13±0.19, 93.69±0.7 and 95.06±0.25, respectively. In vitro microbiological screening of their antifungal activity showed significantly larger zones of inhibition of diameters 25.9±0.25, 25±0.35 and 24.67±0.36 mm, respectively in comparison with the marketed Lamifen® cream which showed a zone of 11.2±0.44 mm diameter. Conclusion: Applying SLNs containing TFH as topical antifungal preparations may be considered as a very promising option as they show good physicochemical characterization with high antifungal activity, which delineates them as a promising dosage form for topical antifungal treatment.