Abstract:
Recently, we have reported the development of quinapyramine sulphate-loaded solid lipid nanoparticles, which showed significantly high drug loading (9.48 ± 0.62%) and sustained release of drug for 60 h. Hence, the objective of the present study was the preclinical evaluation of quinapyramine sulphate-loaded solid lipid nanoparticles for the trypanocidal effect against T. evansi parasite. Nanoformulation showed low haemolysis (<10%) of rat erythrocytes and also to be safe (>60% cell viability) as compared to free quinapyramine sulphate in THP-1 cells. Confocal and flow cytometry analysis confirmed enhanced cellular uptake of Coumarin-6 (C6) solid lipid nanoparticles (C6 SLN) compared to free Coumarin 6. Cellular uptake studies showed C6 SLN could be internalized by THP-1 cell by different mechanisms including lipid-raft, clathrin- and caveolin-mediated pathways. In vitro trypanocidal studies against T. evansi showed that quinapyramine sulphate-loaded solid lipid nanoparticles exhibited low IC50 compared to free quinapyramine sulphate. A confocal microscopy study confirmed that both quinapyramine sulphate and quinapyramine sulphate loaded solid lipid nanoparticles induced significant morphological changes in the T. evansi parasite after treatment. Quinapyramine sulphate equivalent to 7.5 mg/kg in quinapyramine sulphate loaded solid lipid nanoparticles treated T. evansi infected mice showed successful treatment without relapse of infection for 60-days, confirmed by the blood smear and DNA amplification by PCR assay. The present study demonstrated that the quinapyramine sulphate-loaded solid lipid nanoparticles could be a promising advanced veterinary formulation for the treatment of T. evansi infection in animals.