PREPARATION AND EVALUATION OF POROUS TABLETS FOR ORAL VACCINE FOR THE TREATMENT OF ENTEROTOXIGENIC ESCHERICHIA COLI INFECTION

Abstract

quotThe main objective of the present study was to develop a porous sodium alginate tablet formulation loaded with F4 fimbriae antigen for efficacy against Enterotoxigenic Escherichia coli (ETEC) infections in piglet models. Pre-compression parameters of the powder mixes and post compression parameters of tablets have been evaluated. A two-factor three-level full factorial design was employed to determine the optimum concentration of sodium alginate and camphor to develop porous tablets. The effect of subliming camphor on the structure of tablets was examined using a scanning electron microscope. The internal structure of the porous tablet was determined using computed tomography CT scanner. The Loading of F4 fimbrial antigen into the porous tablets was achieved by spiking the F4 fimbrial solution on the tablet surface. The loaded tablets have been coated with Eudragit L100 to protect the F4 fimbriae from acidic gastric environment, proteolytic cleavage by pepsin and to promote subsequent release in the intestine. The pigs were vaccinated with F4 fimbriae loaded porous tablets and the immune response evoked was compared with F4 fimbrial solution. newlineThe results of pre-compression parameters were found to be within prescribed limits. It was observed that both, orally administered F4 fimbrial porous tablets and F4 fimbrial solution induces mucosal immunity, however immunization using porous tablet loaded with F4 fimbriae induces more effective immune response than for the free f4 fimbriae, possibly due to a higher F4 antigen load in the jejunum of the pig. Moreover animals vaccinated with F4 fimbriae in porous tablets showed a significant reduction of F4+ E. coli in faeces which confirm the protection against ETEC contamination by porous tablet group. These results suggest that F4 fimbriae loaded porous tablets could be a promising candidate for an oral vaccine delivery system to induce mucosal and systemic immunity against ETEC infections. newlinequot newline