Three months chemoprophylaxis of shistosomiasis using liposome encapsulated oxamniquine

ABSTRACT

Oxamniquine liposomes of the molar ratio 76, neutral and negatively charged, were prepared by the vortex dispersion method. Entrapped oxamniquine was estimated by HPLC analysis. Percentage drug encapsulated was found to range from 12.4% [neutral liposomes] to 20% [negative liposomes]. Drug-free and oxamniquine liposomes were characterized by particle-size analysis and Differential-scanning-calorimetry. Liver disposition of oxamniquine liposomes in mice, three-months post [s.c.] injection was investigated. Results reveal that oxamniquine liposomes are better liver-targeted than the free drug. Chemoprophylaxis of oxamniquine liposomes against S. mansoni in mice, was assessed for three months where drug liposomes displayed highly significant protection of 44%, unlike the free drug preparation; 1.3%. Stability study of oxamniquine liposomes was conducted on negative and neutral liposomes at -10, 4°, and 25°. Neutral liposomes displayed better sustained release of the drug over the negative ones. Storage at -10° provides more stable drug- liposomes. Sterilization of negatively charged oxamniquine liposomes was conducted employing four doses of gamma radiation of 10, 15, 20 and 25 KGy. Results revealed that 25 KGy is the optimum sterilizing dose, in addition to inferring high stability to the product