Preparation And Characterization Of Acyclovir Nanoparticles By Double Emulsion Technique
Acyclovir (ACV) is one of the most effective and selective agents against viruses of the Herpes group. Its t1/2 is about 2.5 hrs., hence repeated administration of high doses is required (200 mg 5 times daily). Parenteral ACV nanoparticles (NPs) for prolonged systemic delivery were prepared by w/o/w double emulsion (DE) technique using biodegradable polymers. The effect of formulation variables such as ratio of drug to polymer as well as the effect of polymer type [Polylactic acid (PLA), polylactic-co-glycolic (PLGA) 85/15, PLGA 75/25, PLGA 50/50] was studied. Dynamic light scattering system, transmission electron microscopy (TEM), zeta potential, differential scanning calorimetry (DSC) and X-ray powder diffractometry were employed to characterize the fabricated NPs for size and size distribution, surface morphology, surface charge and the physical state of drug in NPs respectively. Encapsulation efficiency (EE) and the in vitro release of ACV in NPs were investigated. Spherical NPs ranging between 590-770 nm in diameter with narrow size distribution were obtained. All particles exhibited a negative surface charge. ACV entrapped in NPs was found in the form of amorphous state. EE was in the range of 30.08% - 51.13%. The release behavior of ACV from the developed NPs exhibited an initial burst release within the first hour followed by a slower release (60% in 48 hrs).
Egyptian Journal of Biomedical Sciences Vol. 23 (1) 2007: pp. 218-236