In vitro release study of diphtheria toxoid loaded chitosan microspheres

The majority of available vaccines require several booster doses to induce effective immunity and these results in significance compliance problems, particularly in developing world. On basis of this, Tetanus toxoid (TT) has the model antigen encapsulated with in chitosan micropheres by emulsion cross-linking method, with an aim of targeting the drug to the site, of inflammation and for controlled release. The in vitro release studies of Tetanus toxoid encapsulated chitosan microspheres were evaluated by using limes flocculation test. In this case Tetanus toxoid started to release only on the 8th day and there after showed a pulsed release upto 40th day. The drug was released continuously over 60 d with no burst effect with a maximum release of 83.33 %. A single administration of chitosan microspheres showed better release kinetics when comparated to markedly available vaccine. These results indicated the possibility of drug being released at a controlled rate from chitosan micro spheres and targeted at the size.