Abstract
Abstract: :
The purpose of this work was to develop the sustained release formulation consisting of biodegradable microspheres of GCV using poly (DL–lactide–co–glycolide) (PLGA) and poly (L–lactide ) (PLLA) for intraocular delivery of GCV. Methods: Microspheres were prepared by dispersing ganciclovir in PLGA and PLLA solutions in methylene chloride at room temperature that were further dispersed in 4% PVA solution. The resulting microspheres were filtered, washed and dried under vacuum for 12 hours. Particle size measurement, size distribution, encapsulation efficiency and in vitro release study were subsequently carried out. Release studies were carried out in isotonic phosphate buffer saline (pH 7.4) in a shaking water bath at 37 °C and 60 rpm. Results:Ganciclovir loaded microspheres were found to be spherical and of uniform particle size. Drug entrapment loading efficiencies of about 50 – 55 % were observed for both PLGA and PLLA microparticles. In the in vitro release studies, controlled release pattern was observed after an initial burst phase. Drug release was observed over a period of 3 – 4 weeks from both PLGA and PLLA microspheres. Conclusion:A new method for preparation of microspheres of Ganciclovir has been developed that requires minimal use of toxic solvents. High drug entrapment efficiencies were observed for both PLGA and PLLA polymers through the current method. These microspheres could result in sustained delivery of ganciclovir to the posterior segment of the eye following intravitreal administration in treatment of Cytomegalovirus retinitis.
Keywords: cytomegalovirus • retina