Investigating the surface properties and bioadhesion of buccal patches.

By using a two-roll milling method, a new bioadhesive polymer patch formulation for drug controlled delivery and consisting of Carbopol 934P (CP), polyisobutylene (PIB), and polyisoprene (PIP) was prepared. The effects of different ratios of CP:PIB:PIP on the surface properties, adhesion, and swelling of buccal patches were investigated. It was found that the surface properties of buccal patches were not only dependent on the CP content but also dependent on the PIB:PIP ratio. The strongest peeling strength was found on the buccal patches with a CP:PIB:PIP ratio of 50:43.75:6.25. The maximum bioadhesion of patches was found following 2- to 8-h contact with the test medium, and this observation could be explained by the interpenetration of macromolecular chains at the polymer-polymer interface (based on the diffusion theory of polymer adhesion).