Absorbable Gels for Modulated Bioavailability of Vaccines

Growing interest in vaccination and diversity of new vaccines which can be administered as a single dose for timely response and prolonged immunity evoked use of absorbable polymers for developing controlled delivery systems. Although absorbable microspheres were explored for controlled delivery of vaccines, poor reproducibility of these systems created a need for a unique single-shot vaccine formulations, which provide timely antibody response and prolonged immunity. Phase I study includes (1) review of available in-house data, that are being generated, on performance of novel gel formers in controlled release of antibiotics, polypeptides, and bovine serum albumin and select suitable compositions for vaccine formulation using ricin toxid (RT) vaccine as a model; (2) synthesis and characterization of selected polymeric compositions; (3) aseptic preparation and characterization of needed formulations; (4) determination of in-vitro release profile of different formulations; (5) determination of vaccine stability in key formulations; (6) completion of an immunization study in mice and determination of antibody response; and (7) use of immunized mice to assess the persistence of protection against an aerosol challenge with RT. Phase I data will be used in designing Phase II plans which emphasize identification, development, and scale-up of one vaccine formulation.