Encapsulated vaccines for the oral vaccination and boostering of fish and other animals
The invention relates to a composition comprising a pharmaceutically active agent and a bioadhesive delivery system that provides for the oral delivery of a vaccine to animals, particularly aquatic animals.
1. A method of preparing a composition for oral delivery of a pharmaceutically active ingredient comprising:
a) preparing an acidic aqueous solution comprising at least one bioadhesive polymer, wherein the acidic aqueous solution has a pH low enough to gelatinize the bioadhesive polymer;
b) combining an oligosaccharide into the solution with the gelatinized bioadhesive polymer to form an oligosaccharide-bioadhesive polymer solution;
c) combining an emulsifier with a sugar, wherein the sugar and emulsifier form a mediating compound;
d) introducing the mediating compound into the oligosaccharide-bioadhesive polymer solution to form a smooth emulsion while maintaining the acidic pH of the solution;
e) adding a pharmaceutically active agent into the smooth emulsion; and
f) precipitating the emulsion into a phosphate containing cross-linking solution.
2. The method of claim 1 , wherein the bioadhesive polymer is selected from the group consisting of chitosan, hyaluronic acid and cationic guar, and combinations thereof.
3. The method of claim 2 , wherein the bioadhesive polymer is present at a concentration of from between 1 and 10%.
4. The method of claim 1 , wherein the oligosaccharide is selected from the group consisting of inulin, fructooligosaccharide and dextrin.
5. The method of claim 4 , wherein the oligosaccharide is present at a concentration of from between 1% and 50%.
6. The method of claim 1 , wherein the mediating compound comprises at least one emulsifier selected from the group consisting of monoglycerides, sorbitan esters, propylene glycol esters, lecithin, polysorbates and sucrose esters, and/or at least one sugar selected from the group consisting of glucose, sucrose and trehalose.
7. The method of claim 1 , wherein the mediating compound comprises an emulsifier/sugar complex containing 0.5 to 12.5% w/w emulsifier and 5-30% w/w sugar.
8. The method of claim 1 , wherein the pharmaceutically active agent is selected from immunogenic peptides and proteins including recombinant vectors to deliver and express genes encoding immunogenic proteins, intact inactive, attenuated and infectious viral particles; intact killed, attenuated and infectious prokaryotes; intact killed, attenuated and infectious protozoans and intact killed, attenuated and infectious multicellular pathogens.
9. The method of claim 1 , wherein the pharmaceutically active agent is a Salmon Rickettsial Septicaemia vaccine.
10. The method of claim 1 , wherein the at least one bioadhesive polymer is selected from the group consisting of chitosan, hyaluronic acid, cationic guar, and combinations thereof; wherein the bioadhesive polymer is present at a concentration of between 1% and 10%, wherein the at least one oligosaccharide is selected from the group consisting of inulin, fructooligosaccharide and dextrin, wherein the oligosaccharide is present at a concentration of between 1% and 50%, wherein the at least one mediating compound comprises an emulsifier/sugar complex containing 0.5 to 12.5% w/w emulsifier and 5-30% w/w sugar.