Principle and investigation of the bioadhesion mechanism of solid dosage forms.

The development of bioadhesive tablets requires a good knowledge of their adhesion mechanism and the possibility of using an accurate in vitro evaluation technique. The bioadhesion mechanism is not basically different from the general adhesion mechanism, but it is necessary to take into account the biological nature of at least one of the two substrates involved in the process. The hydrated joint created at the molecular interface, resulting from the inter-penetration of the polymeric chains of the mucin and the bioadhesive product, is especially interesting, because its viscoelastic properties make it a damping device for the stresses transmitted to the bioadhesive surface.