Co-delivery of trifluralin and miltefosin with enhanced skin penetration and localization in Leishmania affected macrophages

Abstract

In this study, Trifluralin (TRF) co-loaded with Miltefosine (MTF) in nano transfersomes (NTs) were prepared aiming their enhanced penetration topically with improved macrophage targeting and antileishmanial effects. Formulations were optimized in a series of experiments based on their particle size, polydispersity index (PDI), drug incorporation and deformability index. TEM analysis was performed to check morphology of NTs. TRF-MTF co-loaded NTs were further incorporated into chitosan gel to obtain better retention. In vitro release and Ex vivo permeation studies of the optimized TRF-MTF co-loaded NTs were conducted to check dissolution behavior and skin permeation of the developed formulation as compared to the drug solutions and TRF-MTF co-loaded NTs gel. Macrophage uptake and antileishmanial efficacy of the developed formulation was also investigated. The optimized formulation had a particle size of 188.5 nm with rounded morphology, PDI of 0.101, and deformability index of 0.987. The drug incorporation of TRF and MTF were respectively found as 91% and 88%. Controlled and significantly enhanced drug release and augmented skin penetration was observed from the TRF-MTF co-loaded NTs as compared to pure drugs. Significant uptake of the TRF-MTF co-loaded NTs by the macrophage proved greater intracellular infiltration via the skin barriers. In vitro anti-leishmanial study exhibited 6-folds and 5-folds decrease in the respective IC50 values of TRF-MTF co-loaded NTs when used against Leishmania (L.) tropica amastigotes and promastigotes. This study exhibited the efficacy of NTs when loaded with dual drugs for enhanced skin penetration and macrophage localization.