Design of Single Dose Control Release Device for Antigen Delivery based on Poly (Lactic-Co- Glycolic Acid)

Vaccines are non pathogenic construct of pathogens, which exploit the ability of immune system to mount specific response against a particular pathogen, thereby protecting the host against that pathogen. The incidence of many infectious diseases have gone down considerably during last several decades as a consequence of vaccination, but successful vaccination often requires multiple immunizations. Thus the development of new vaccines, particularly the conversion of multiple dose vaccine into single dose vaccine has become an area of research. In order to be fully immunized against most infectious diseases like hepatitis B, tetanus, diphtheria, the successful administration of three doses is needed. To increase immunization coverage, to reduce excessive vaccine wastage, and to reduce the cost of immunization, vaccine in the formats other than the standard multidose formats is very much required. In the present article, we review key issues in developing single dose control release device for antigen delivery with special emphasis on design and use of poly (lactic-coglycolic acid) or (PLGA) microparticles for controlled delivery of antigen , difficulties in encapsulating antigen inside PLGA microparticles and the various approaches which have been used successfully to encapsulate antigen inside microparticles.