Leishmaniasis - Drugs, Nanotechnology Based Delivery Systems and Recent Patents Survey

Background: Leishmaniasis is one of the most abandoned tropical infectious diseases in terms of drug innovation and development. The disease can be characterized by at least four syndromes: cutaneous leishmaniasis (CL), muco-cutaneous leishmaniasis (MCL), visceral leishmaniasis (VL) - also known as kala-azar in the Indian sub-continent or black fever, which is the most firm form of the disease being lethal if untreated, and post-kala-azar dermal leishmaniasis (PKDL). Most antileishmanial drugs are highly lethal, present resistance issues or require hospitalization, being therefore not adequate to the field. Methods: The advancement in the development of new formulation against leishmaniasis is critically discussed here. Several efforts have been made to overcome the barriers involved in the treatment of leishmaniasis. Recently improvement have been achieved by combination therapy dropping the time and cost of treatment. Nonetheless, new drugs are still directly needed. Results: Colloidal carriers extensively represent the drug delivery systems (DDSs) for intracellular localization of antileishmanial compounds in macrophages rich organs like liver, spleen and bone marrow. These DDSs offer superior therapeutic efficacy over the conventional treatment in terms of site specific drug delivery with reduced side effects. They also express a new hope for the effective treatment of leishmaniasis. Conclusion: In this review, we describe the current leishmaniasis treatments and their limitations. We also discuss the promising antileishmanial natural products, nanotechnology based new strategies to deliver solid candidates specifically against VL, their mechanism of penetration and the recent patents related to leishmaniasis. Moreover, the present article is a compilation of the potent antileishmanial hybrids reported in number of patents.