Preparation of intravenous stealthy acyclovir nanoparticles with increased mean residence time

A major cause of thromboplebitis, during acyclovir (ACV) parenteral administration is the high pH of its reconstituted solution (pH 11). Its plasma half life is 2.5 h, requiring repeated administration which may result in excess of drug solubility leading to possible renal damage and acute renal failure. The present study reports the efficiency of stealthy ACV nanoparticles (NPs) to increase the mean residence time of the drug 29 times. It caused a marked decrease in thrombophlebitis when injected into rabbit's ear vein. The polymers used were (Poly lactic acid, polylactic-co-glycolic (PLGA) 85/15, PLGA 75/25, PLGA 50/50). Particles were evaluated for their encapsulation efficiency, morphology, particle size and size distribution, zeta potential, and in vitro drug release. Small NPs (280-300 nm) with 60% drug release after 48 h were obtained. Among the block copolymer used, poloxamer 407 was of superior coating properties with a coat thickness in the range of 1.5-8.3 nm and a decreased surface charge.