Formulation and Evaluation of Microparticulate System for the Development of Pneumonia and Influenza Vaccines

Abstract

In recent years vaccine research has gained a tremendous interest from both industries as well from the academic sectors. There are number of vaccines available in the market and still there is a scope of improvement in most of the marketed vaccines. The antigens used in vaccination are in general large molecules, either protein or polysaccharide based. These antigens can lead to specific antibodies that will protect our body from the infection. Some of the antigens are stable, however majority of them are instable and sensitive resulting in problems during formulation, storage.

Formulation of protein or polysaccharide has always been a challenge for scientists due to several characteristics of the antigen and the dosage from itself. Microparticle is on the the dosage forms that have shown promising results in several vaccine studies in the past. In this study we have evaluated microparticle formulations for two infectious diseases namely, Pneumonia and Influenza. Both these are respiratory infections and the vaccinations against these are highly recommended by the Center for Disease Control. In particularly for Influenza the vaccination is recommended every year.

In this research we have used two novel approaches to formulate these antigens using microparticles. The pneumococcal polysaccharide antigens are usually less immunogenic in nature and hence to potentiate their immune response the antigens were formulated in a cross linked albumin matrix. In case of Influenza vaccines, we have attempted to vaccinate via oral route of administration after formulating inactivated form of influenza virus in an enteric coated microparticle formulation.

Upon formulation both theses vaccines were characterized for their physical properties such as particle size, zeta potential and also the bioactivity of these antigens in microparticles were measured using antigen specific bio assays, Further invivo studies were carried out in mice to evaluate the adaptive immune responce elicited by microparticle based vaccines. The results have been promising with increase in antibody titers for vaccine formulations and also better protection was observed in case of Influenza vaccine, Overall these promising results further emphasize the use of microparticles as a tool to deliver vaccine antigens effectively.