Nitazoxanide and quercetin co-loaded nanotransfersomal gel for topical treatment of cutaneous leishmaniasis with macrophage targeting and enhanced anti-leishmanial effect

Purpose: Anti-leishmanial medications administered by oral and parenteral routes are less effective for treatment of cutaneous leishmaniasis (CL) and cause toxicity, hence targeted drug delivery is an efficient way to improve drug availability for CL with reduced toxicity. This study aimed to develop, characterize and evaluate nitazoxanide and quercetin co-loaded nanotransfersomal gel (NTZ-QUR-NTG) for the treatment of CL. Methods: NTZ-QUR-NT were prepared by thin film hydration method and were statistically optimized using Box-Behnken design. To ease the topical delivery and enhance the retention time, the NTZ-QUR-NT were dispersed in 2 % chitosan gel. Moreover, in-vitro drug release, ex-vivo permeation, macrophage uptake, cytotoxicity and anti-leishmanial assays were performed. Results: The optimized formulation indicated mean particle size 210 nm, poly dispersity index (PDI) 0.16, zeta potential (ZP) −15.1 mV and entrapment efficiency (EE) of NTZ and QUR was 88 % and 85 %, respectively. NTZ-QUR-NT and NTZ-QUR-NTG showed sustained release of the incorporated drugs as compared to the drug dispersions. Skin permeation of NTZ and QUR in NTZ-QUR-NTG was 4 times higher in comparison to the plain gels. The NTZ-QUR-NT cell internalization was almost 10-folds higher than NTZ-QUR dispersion. The cytotoxicity potential (CC50) of NTZ-QUR-NT (71.95 ± 3.32 μg/mL) was reduced as compared to NTZ-QUR dispersion (49.77 ± 2.15 μg/mL. A synergistic interaction was found between NTZ and QUR. Moreover, in-vitro anti-leishmanial assay presented a lower IC50 value of NTZ-QUR-NT as compared to NTZ-QUR dispersion. Additionally, a significantly reduced lesion size was observed in NTZ-QUR-NTG treated BALB/c mice, indicating its antileishmanial potential. Conclusion: It can be concluded that nanotransfersomal gel has the capability to retain and permeate the incorporated drugs through stratum corneum and induce synergetic anti-leishmanial effect of NTZ and QUR against cutaneous leishmaniasis.