NANOSTRUCTURED LIPID CARRIERS CONTAINING ANNATTO OIL (BIXA ORELLANA L.): AN ALTERNATIVE POTENTIAL AGAINST CUTANEOUS LEISHMANIASIS
Nanostructured Lipid Carriers, Bixa orellana L., cutaneous leishmaniasis.
Leishmaniasis is one of the leading Neglected Tropical Diseases (NTD). Every year millions of people are infected, however the drugs used have serious problems and low effectiveness. In this way the development of drug alternatives becomes necessary. Nanotechnology has been outstanding for presenting efficient solutions in the development of new drugs. For this reason, the objective of this work was to incorporate the oil fraction of annatto (Bixa orellana L.), a plant active with proven antileishmania activity, to Nanostructured Lipid Carriers (NLC), known to be the second generation of lipid nanoparticles. The nanoparticles were produced by the fusion-emulsification method and characterized in terms of particle size, polydispersity index, morphology, zeta potential, storage stability for 90 days, encapsulation efficiency, thermal stability, crystalline profile, in vitro cytotoxicity and activity antileishmania in vitro, in addition to the evaluation of the influence of 3% (m / m) of synthetic Laponite® clay on the system. The tests showed the effectiveness of the production method, with nanoparticles ranging from 173.73 nm ± 1.15 to 185.23 nm ± 1.80, polydispersity of less than 0.3 and zeta potential between -23.07 mV ± 0.15 and -39.13 mV ± 0.50 and stability maintained for 90 days, with no variation due to the presence of clay. Carriers remained stable when submitted to body temperature (32ºC - 37ºC), with mass loss at approximately 100ºC. The crystalline structure of the nanocarriers promoted the encapsulation of 78.92 ± 2.89 and 52.54 ± 3.41 in the formulations with 2% and 4% of annatto oil, respectively. Carriers presented antileishmania activity similar to Amphotericin B and higher than Glucantime® and unencapsulated annatto oil. These results demonstrate a stable system with proven biological activity and should therefore be seen as a potential therapeutic alternative for the treatment of cutaneous manifestations of leishmaniasis and therefore requiring further studies and investments.