Bilayer films for mucosal (genetic) immunization via the buccal route in rabbits.
OBJECTIVE
The oral buccal mucosa may be an ideal site for mucosal immunization, allowing for the needle-free administration of cost-effective vaccines. A novel mucoadhesive bilayer film was developed to test the feasibility of this route of immunization in rabbits.


METHODS
Bilayer films were developed using different ratios of Noveon and Eudragit S-100 as the mucoadhesive layer and a pharmaceutical wax as the impermeable backing layer. Optimal 3/8-inch films were post-loaded with 100 microg of plasmid DNA (CMV-beta-gal) or beta-galactosidase protein. The in vitro release rates and stability of the postloaded antigens were determined. The films were applied to the buccal pouch of rabbits on days 0. 7, and 14, and the humoral and splenocyte proliferative immune responses to beta-gal were determined through day 28 and compared to those responses after conventional subcutaneous injection of adjuvanted protein.


RESULTS
The weight ratio of Noveon and Eudragit S-100 had a significant effect on adhesion time of bilayer films. Postloaded plasmid DNA and beta-gal remained stable after being released from bilayer films (release of -60-80% in 2 h for both). Buccal immunization using novel bilayer films (109 +/- 6-microm thickness) containing plasmid DNA led to comparable antigen-specific IgG titer to that of subcutaneous protein injection. All rabbits immunized with plasmid DNA via the buccal route but none by the subcutaneous route with protein antigen demonstrated splenocyte proliferative immune responses.


CONCLUSIONS
The feasibility of buccal (genetic) immunization with these novel bilayer films was demonstrated.
Division of Pharmaceutical Sciences College of Pharmacy University of Kentucky, Lexington 40536-0082, USA.
Zhengrong
Z
Cui
Russell J
RJ
Mumper
D000269:Adhesives / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000278:Administration, Buccal; D000818:Animals; D016503:Drug Delivery Systems / Q000379:methods*; D005260:Female; D018014:Gene Transfer Techniques; D007114:Immunization / Q000379:methods*; D009061:Mouth Mucosa / Q000187:drug effects* / Q000378:metabolism; D010957:Plasmids / Q000008:administration & dosage / Q000235:genetics* / Q000493:pharmacokinetics; D011109:Polymethacrylic Acids / Q000008:administration & dosage / Q000493:pharmacokinetics; D011817:Rabbits; D014885:Waxes / Q000493:pharmacokinetics
D000269:Adhesives; D011109:Polymethacrylic Acids; D014885:Waxes; C038300:methylmethacrylate-methacrylic acid copolymer