Development and evaluation of porous tablets of sodium alginate for treatment of Enterotoxigenic Escherichia coli infection

Enterotoxigenic Escherichia coli (ETEC) infections result in large mortality rate and usually a frequent cause of diarrhea in infants. To prevent enterotoxigenic escherichia coli infections animal needs an active mucosal immunity at the moment of weaning. In the present study, F4 loaded porous sodium alginate tablets were prepared by direct compression technique for oral vaccination using ammonium carbonate as a pore former. In order to prevent the release the antigen in upper GI tract and to release it at target site nanoparticles were coated with Eudragit S100 which will protect the antigen against the detrimental effects in the gastro-intestinal tract. Tablets were evaluated for pharmaco-technical properties and results were found to be satisfactory. SEM studies were conducted in order to show the porous surface of tablets. Ammonium carbonate as a pore forming agent proves to be promising and was successful in creating pores on surface of tablets through which F4 was loaded in tablets. SEM had given a clear picture showing major and minor pore with different pore size. It was found that an increase in pore forming agent leads to decrease in hardness and disintegration time of porous tablets. Mucosal immune response study revealed that, immune response was elicited and animals vaccinated with porous tablets group shows a significant reduction in excretion of F4(+) E coli. Studies indicate that a solid vaccine formulation will be more efficient and these systems can contribute to the development of oral vaccines in veterinary as well as in human medicines.