Abstract
Bioadhesion could lead to the solution of bioavailability problems resulting from a too short stay of the pharmaceutical dosage form at the absorption or activity level of the active ingredient. Bioadhesion stages are: intimate contact resulting from a good wetting of the bioadhesion surface and the swelling of the bioadhesive polymer, then penetration of the bioadhesive into the crevice of the tissue surface or interpenetration of bioadhesive chains with those of the mucus, and finally low chemical bonds. date, the most important bioadhesive polymers are polycarbophil a Carbopol 934. Methods of studying bioadhesion are described as well as the existing bioadhesive dosage forms.