DEVELOPMENT AND CHARACTERIZATION OF HBSAG LOADED PLGA MICROSPHERES FOR MUCO-ADHESIVE DELIVERY SYSTEMS

Abstract

This work was designed to develop muco-adhesive PLGA microspheres containing HBsAg and to characterize them. The Hepatitis B surface antigen was estimated by using BCA kit and by ELISA methods. Specific antibodies against HBsAg were measured using AUSAB®EIA Kit. Microspheres were prepared by double emulsion evaporation technique. Formulations PLGA1 to PLGA7 were prepared by changing the concentration of PLGA from 3 to 9% w/v, while the PVA concentration (6% w/v) was kept constant. In the case of formulations PVA1 to PVA10, PLGA concentration was kept constant at 4% w/v while varying the concentration of PVA from 2 to 11 % w/v. Surface morphology and size analysis of PLGA microspheres were done by using bright field microscope and by SEM analysis. The average size range of the microspheres varied from 2.56 µm to 41.27 µm. The size of the microspheres was directly proportional to the concentration of PLGA and was inversely proportional to the concentration of PVA. The percentage entrapment efficiency of the HBsAg was studied and was ranged from 28.36 to 34.54 for the formulations. Four microspheres formulations which have been produced within the size range of 1-10 µm have been selected for the in-vitro release studies. The in-vitro cumulative % release pattern of all the three formulations was very similar except PLGA2. The microspheres will be further improved for the entrapment efficiency and for a better in- vitro release profile.