Formulation, in vitro evaluation and therapeutic effect of chitosan coated pluronic F127 micelles containing miltefosine for the treatment of visceral leishmaniasis in domestic dogs naturally infected by Leishmania infantum.

There are a limited number of chemotherapeutic agents for the treatment canine visceral leishmaniasis (CVL). This study aimed to formulate and assess micellar formulation of miltefosine (MTF) to increase antileishmanial therapeutic effects in dogs naturally infected by Leishmania (L) infantum for the first time. MTF loaded pluronic F127 (PF/MTF) micelles were formulated and coated with chitosan (Cs/PF/MTF). Toxicity of compounds was evaluated. The in vitro and in vivo antileishmanial effect of Cs/PF/MTF was examined in L. infantum promastigotes and amastigotes as well as naturally infected dogs by L. infantum. In-vitro efficacy studies in promastigotes and amastigotes demonstrated that inhibitory concentration (IC50) of Cs/PF/MTF was significantly lower in comparison to miltefosine. In vivo data showed that Cs/PF/MTF is more effective against CVL compared with miltefosine alone. The result of this study indicated that intravenous injection of new formulation of Cs/PF/MTF was tolerated and treated on L. infantum naturally infected dogs with the dosages of 170 μg/kg daily for 28 days.