Formulation and evaluation of oil-in-water emulsions of piperine in visceral leishmaniasis

Abstract

Present studies are aimed to find out the utility of oil-in-water emulsions also known as lipid nanospheres (LN) or fat emulsions for delivering piperine for the treatment of visceral leishmaniasis. Lipid nanosphere formulations of piperine were prepared using soybean oil, egg lecithin, cholesterol, stearylamine and phosphatidylethanolamine distearylmethoxypolyethyleneglycol (DSPE-PEG) by homogenization followed by ultrasonication of oil and aqueous phases. Antileishmanial activity of all the formulations was assessed in BALB/c mice infected with Leishmania donovani AG83 for 60 days. A single dose (5 mg/kg) of piperine, or lipid nanospheres of piperine (LN-P), or lipid nanosphere of piperine with stearylamine (LN-P-SA) or pegylated lipid nanospheres of piperine (LN-P-PEG) was injected intravenously. Mice were sacrificed after 15 days of treatment with piperine or formulations and Leishman Donovan Unit (LDU) is counted. Toxicity of formulations and pure piperine was assessed in normal mice. The size distribution of formulations ranged from 200 to 885 nm. Piperine reduced the parasite burden in liver and spleen by 38% and 31% after 15 days post infection respectively. LN-P reduced the parasite burden in liver and spleen by 63% and 52% after 15 days post infection, respectively. LN-P-PEG reduced the parasite burden in liver and spleen by 78% and 75% after 15 days post infection, respectively. LN-P-SA reduced the parasite burden in liver and spleen by 90% and 85% after 15 days post infection, respectively. LN-P, LN-P-PEG, LN-P-SA treated mice did not show any significant changes in the serum levels of SGOT, ALP, creatinine and urea compared to normal mice. Stable and sterile formulations of lipid nanospheres of piperine were developed. A single dose of 5 mg/kg of lipid nanospheres of piperine could significantly reduce the liver and splenic parasite burden.