Formulation of topical NLCs to target macrophages for cutaneousleishmaniasis

Abstract

The present work aimed to synthesize drug loaded nanostructured lipid carriers (NLCs) for treatment of cutaneousleishmaniasis (CL). Topical drug delivery is a favourable option in treatment of localized cutaneousleishmaniasis (LCL) and is always considered superior over systemic therapy and intralesional antimony injections. Curcumin was chosen as model antileishmanial drug and drug loaded NLCs (Cur-NLCs) were prepared by hot homogenization followed by probe sonication technique. Prepared Cur-NLCs were characterized for particle size (312 ± 1.89 nm), encapsulation efficiency (88 ± 2.45%), zeta potential (−38 ± 0.93 mV) and Polydispersity index (0.305 ± 0.17). Blank and drug loaded NLCs were characterized for morphology using scanning electron microscopy (SEM) and FTIR was done to study any interaction between excipients. Cur-NLCs were also characterized for in vitro drug release and ex vivo skin permeation and deposition study. Moreover, targeting potential to macrophages and deeper skin layers was evaluated using fluorescence microscopy. A higher drug deposition in stratum corneum and deeper skin layers was achieved with Cur-NLCs gel as compared to curcumin reference gel (RG). The in vitro antileishmanial assay against promastigotes and axenic amastigote like cells (AALCs) demonstrated Cur-NLCs (IC50 values of 105 μg/ml and 190 μg/ml against promastigotes and AALCs respectively) to be superior as compared to plain curcumin solution (IC50 values of 165 μg/ml and 243 μg/ml against promastigotes and AALCs respectively). Results suggested that topical application of drug loaded NLCs can lead to targeted delivery of antileishmanial drugs to site of action i.e., infected macrophages residing in deeper skin layers.