Physicochemical and immunological studies on the stability of free and microsphere-encapsulated tetanus toxoid in vitro

Formulation and Characterization of Immunoreactive Tetanus Toxoid Biodegradable Polymer Particles

“…More than 70% of the encapsulated TT was released in a continuous manner over an extended period of 140 days. The in vitro release pro les of immunopotent TT from polymer particles obtained in this study was more uniform in comparison to the previously reported information (Alonso et al 1993;Xing et al 1996;Johansen et al 1998).…”

“…In most of the reported observations on controlled release formulation of TT from PLA or PLGA polymers, the antibody response have always been lower than that obtained from two conventional doses of alum adsorbed TT (Xing et al 1996;Kersten et al 1996;Gupta et al 1997;Audran et al 1998;Tobio et al 2000). The low antibody response produced by PLA or PLGA encapsulated TT particles may be due to either altered immunological responses as a result of antigen degradation during particle formation or to biochemical changes in the toxoid originating from, particle loading and subsequent degradation during storage or following administration (Alonso et al 1993;Chang and Gupta 1996).…”

Comparison of the Diphtheria Mutant Toxin, Crm197, with a Haemophilus Influenzae Type‐b Polysaccharide‐Crm197 Conjugate by Optical Spectroscopy

“…Physico-chemical methods have been useful in determining the structural identity, purity and integrity of various vaccine components Xing et al, 1996). We have used optical methods to compare the glyco-conjugated CRM197 with native CRM197 and its parent molecule, diphtheria toxin.…”

Vaccine adjuvants: Current challenges and future approaches

“…The two most widely studied polymer classes for controlled release vaccines are polyesters [155][156][157][158][159][160][161][162][163][164] and polyanhydrides. 87,[165][166][167][168][169][170][171][172][173][174][175][176] Other classes of polymeric compounds have been evaluated and shown to successfully deliver antigen to laboratory animals.…”

“…Prolonged exposure to aqueous or acidic environments has been shown to be detrimental to the stability and immunogenicity of proteins, especially the proteins used in recombinant and subunit vaccines, for example, TT and DT. 162,163 Some attempts to minimize this acidity have been recently evaluated by incorporating a basic compound like magnesium carbonate (MgCO 3 ) into PLGA microspheres. 164 However, subsequent analysis indicated that while MgCO 3 did not significantly improve peptide stability, it did enhance the antibody production, acting as a potential adjuvant.…”