Comparison of classical, stealth and super-stealth liposomes for intravenous delivery of lumefantrine: Formulation, characterization and pharmacodynamic study

Purpose: To develop and compare classical liposomes (CL), stealth liposomes (SL) and super-stealth liposomes (SSL) encapsulating lumefantrine for intravenous administration. Method: CL, SL or SSL were prepared by thin-layer evaporation method and evaluated for particle size, polydispersity index (PdI), encapsulation efficiency and short-term stability. Pharmacodynamic study using mice infected with Plasmodium berghei was also carried out. Results: The particle sizes (nm) and PDI of the liposomes were: CL (248 ± 44.89; 0.78 ± 0.02), SL (235.8 ± 45.18; 0.39 ± 0.06) and SSL (238.2 ± 23.0; 0.24 ± 0.04). Encapsulation efficiency was highest in SSL (66 %), followed by SL (44.4 %) and then by CL (42.5 %). SSL was the most stable after 72 h of storage. In vivo, lumefantrine produced significant reduction in parasitaemia after 7 days (p < 0.05) by SSL (68.3 ± 8.9 %) followed by CL (55.8 ± 15.2 %) and then SL (53.4 ± 14.9 %). Conclusion: SSL formulation of lumefantrine exhibits good physicochemical and pharmacodynamic potentials and should be further investigated in future studies for the treatment of malaria.