An in vitro assessment of bioadhesive zinc/carbomer complexes for antimicrobial therapy within the oral cavity

The effectiveness of antimicrobial agents in the oral cavity is limited by their retention at the site of action. In this work the antimicrobial cation zinc was complexed with the bioadhesive agent Carbopol 971P, in order to allow an extended antimicrobial effect. Zinc ions were shown to form stable complexes with the polymer, and were not released into distilled water. However, in the presence of other cations, it was possible to displace zinc over an extended period. A low pH was seen to enhance zinc release. The complexes were found to have similar bioadhesive properties to the polymer alone when tested using a buccal cell adsorption model and texture probe analysis. It was concluded that this complex shows promise as a means of allowing the extended delivery of zinc ions locally within the oral cavity.