Tensile bond strength of a polymeric intra-buccal bioadhesive: the mucin role.

The intra-bucal polymeric bioadhesive systems that can stay adhered to the oral soft tissues for drug programmed release, with the preventive and/or therapeutic purpose have been employed for large clinical situations. A system based on hydroxypropyl methyl cellulose/Carbopol 934 T M /magnesium stearate (HPMC/Cp/StMg), was developed with the sodium fluoride as an active principle. This kind of system was evaluated according to its resistance to the removal by means of physical test of tensile strength. Swine buccal mucosa extracted immediately after animals' sacrifice was employed as a substrate for the physical trials to obtain 16 test bodies. Artificial saliva with or without mucin was used to involve the substrate/bioadhesive system sets during the trials. Artificial salivas viscosity were determined by means of Brookfield viscometer, and they showed 10,0 cP artificial saliva with mucin, and 7,5 cP artificial saliva without mucin. The tensile strength assays showed the following averages: 12.89 Pa for the group "artificial saliva with mucin", and 12.35 Pa for the group "without mucin". Statistical analysis showed no signifficant difference between the assays for both artificial salivas, and we can conclude that the variable mucin did not interfer with the bioadhesion process for the polymeric devices.