Formulation, in vitro and in vivo evaluation of halofantrine-loaded solid lipid microparticles

Context: Formulation, characterization, in vitro and in vivo evaluation of halofantrine-loaded solid lipid microparticles (SLMs). Objective: The objective of the study was to formulate and evaluate halofantrine-loaded SLMs. Materials and methods: Formulations of halofantrine-loaded SLMs were prepared by hot homogenization and thereafter lyophilized and characterized using particle size, pH stability, loading capacity (LC) and encapsulation efficiency (EE). In vitro release of halofantrine (Hf) from the optimized SLMs was performed in SIF and SGF. In vivo study using Peter's Four day suppressive protocol in mice and the mice thereafter subjected to histological studies in kidney and liver. Results: Results obtained indicated that EE of 76.32% and 61.43% were obtained for the SLMs containing 7% and 3% of Hf respectively. The SLMs loaded with 3% of Hf had the highest yield of 73.33%. Time-dependent pH stability analysis showed little variations in pH ranging from 3.49 +/- 0.04 to 4.03 +/- 0.05. Discussion: The SLMs showed pH-dependent release profile; in SIF (43.5% of the drug for each of H-2 and H-3) compared with SGF (13 and 18% for H2 and H3 respectively) after 8 h. The optimized SLMs formulation and Halfan (R) produced a percentage reduction in parasitemia of 72.96% and 85.71% respectively. The histological studies revealed that the SLMs formulations have no harmful effects on the kidney and liver. Conclusion: SLMs formulations might be an alternative for patients with parasitemia as there were no harmful effects on vital organs of the mice.