Microencapsulation for the gastric passage and controlled intestinal release of immunoglobulin Y.

Avian immunoglobulin (Ig) Y is a promising alternative for the treatment and prevention of enteric infections, and has shown to be effective against a number of gastrointestinal pathogens, including Escherichia coli, Salmonella, and rotavirus. However, its application is limited by its sensitivity to human gastrointestinal conditions. Here, we report on the enteric coating of IgY-containing granules with a pH-sensitive methacrylic acid copolymer. A 35% (w/w) polymer coating was found to protect IgY from gastric inactivation in vitro, maintaining greater than 95% activity after 6 h in simulated gastric fluid. The IgY was slowly released from the microencapsulated granules upon exposure to simulated intestinal fluid, and retained 80% activity after 8 h exposure to pancreatic enzymes. In vivo, using pigs as a model of human digestion, the encapsulated IgY retained significantly more activity than non-encapsulated IgY, indicating that microencapsulation with a methacrylic acid copolymer may be an effective method of protecting IgY from gastrointestinal inactivation, enabling its use for oral passive immunotherapy.