Evaluation of a chloroquine hydrogel for topical treatment of leishmaniasis in BALB/c mice infected with Leishmania (L.) amazonensis.

Abstract

Leishmaniasis, a challenging disease to treat due to the intracellular location of the parasite and host immune modulation, requires innovative treatment solutions. This study evaluates a chloroquine-based hydrogel for topical use, targeting a localized and less invasive approach to leishmaniasis treatment. Thus, this study aimed at evaluating the skin permeation potential of the antimalarial chloroquine and also to evaluate the less invasive, topical treatment in murine models infected by Leishmania (Leishmania) amazonensis. For this end, a formulation was created, containing chloroquine (CQ), which had its release profile assessed through the ex vivo skin permeation assay using Sus scrofa domesticus skin. Afterward, the susceptibility profile of L. (L.) amazonensis in vivo in BALB/c mice was assessed over a 15-day treatment period. This study highlights the potential of chloroquine hydrogel as a topical treatment for tegumentary leishmaniasis, with significant reductions in parasite load and minimal side effects observed. The formulation demonstrated a 15% permeation rate during 12 h, with 20.26% on the 42nd day. A significant reduction in parasite load was observed in the treatment group. Thus, the results presented here point to the need for further pre-clinical trials with a higher concentration of the drug, other formulations and against other Brazilian species of Leishmania. Future studies should explore higher drug concentrations, alternative formulations, and other Leishmania species to expand the therapeutic potential of this approach.