Abstract
Despite technological advances made in the pharmaceutical antimalarial field, malaria remains one of the major causes of mortality worldwide. Resistance of malaria parasites to nearly all current antimalarials in clinical use is one of the primary challenges that face researchers. In this study, the prophylactic efficacy of a single-dose in situ gel formulation containing chloroquine or silver sulfadiazine compared to drug alone was examined in Plasmodium berghei-infected Balb/c mice. Intramuscular injection of in situ 30% polylactide-co-glycolide (1:1) in N-methyl-2-pyrrolidone gel containing silver sulfadiazine (5.25 mg/kg body weight) or chloroquine phosphate (40 mg/kg body weight) failed to protect a challenge of 106 parasitized erthrocytes intraperotoneal injected 4 days following treatment. This failure was due to rapid release and clearance of the antimalarial before appearance of parasitemia. The presence of in situ antimalarial-cont aing gels was not detrimental to murine kidney and liver funcrion based on measurements of standard biochemical blood markers. Additional studies are warranted to determine the optimal in situ antimalarial gel formulation to generate appropriate drug pharmacokinetics for a prophylaxis against malaria infection.