Self-nanoemulsifying drug delivery system to improve transcorneal permeability of voriconazole: in-vivo studies.

OBJECTIVE: This study investigates the effectiveness of self-nanoemulsifying drug delivery system (SNEDDS) in improving voriconazole transcorneal permeability. METHODS: Voriconazole-SNEDDS was prepared with isopropyl myristate, PEG 400, Tween 80® and Span 80® and was subjected for physicochemical characterization after reconstitution with NaCl 0.9% (1/9; v/v). In-vitro antifungal activity was assessed and compared with the marketed formulation. In-vivo studies, namely ocular irritation test via modified Draize test and pharmacokinetic study, were investigated using rabbit as animal model. KEY FINDINGS: Voriconazole-SNEDDS presented a droplet size of 21.353 ± 0.065 nm, a polydispersity index of 0.123 ± 0.003, a pH of 7.205 ± 0.006 and an osmolarity of 342.667 ± 2.517 mOsmol/l after reconstitution with NaCl 0.9%. Voriconazole-SNEDDS minimum inhibitory concentration (MIC90 ) was similar to the one of marketed formulation for Candida species while it was significantly lower (P < 0.001) for Aspergillus fumigatus. Draize test revealed that Voriconazole-SNEDDS was safe for ocular administration. Voriconazole maximum concentration (5.577 ± 0.852 µg/ml) from SNEDDS was higher than marketed formulation (Cmax  = 4.307 ± 0.623 µg/ml), and the Tmax was delayed to 2 h. The area under the concentration-time curve value of Voriconazole-SNEDDS was improved by 2.419-fold. CONCLUSION: Our results suggest that SNEDDS is a promising carrier for voriconazole ocular delivery and this encourages further clinical studies.

Voriconazole-loaded self-nanoemulsifying drug delivery system (SNEDDS) to improve transcorneal permeability.

The aim of this study was to develop self- nanoemulsifying drug delivery system (SNEDDS) to improve the transcorneal permeability of voriconazole. A 'mixture design around a reference mixture' approach was applied. This latter included four components, namely, isopropyl myristate, PEG 400, Tween® 80 and Span® 80 as oil, co-solvent, surfactant and co-surfactant, respectively. Droplet size was selected as response. The effect of mixture components on droplet size was analyzed by means of response trace method. Optimal formulation was subjected to stability studies and characterized for droplet size, polydispersity index (PDI), pH, osmolarity, viscosity and percentage of transmittance. Ex-vivo transcorneal permeation of the optimal and the marketed formulations was carried out on excised bovine cornea using Franz cell diffusion apparatus. Optimal voriconazole loaded-SNEDDS showed moderate emulsification efficiency and was characterized by a droplet size of 21.447 ± 0.081 nm, a PDI of 0.156 ± 0.004, a pH of 7.205 ± 0.006, an osmolarity of 310 mosmol/Kg and a viscosity of 8.818 ± 0.076 cP. Moreover, it presented an excellent stability and exhibited a significant improvement (p < 0.05) in apparent permeability coefficient (1.982 ± 0.187 × 10-6 cm/s) when compared to commercialized formulation (1.165 ± 0.106 × 10-6 cm/s). These results suggest that SNEDDS is a promising carrier for voriconazole ocular delivery.