Mucoadhesion is the ability of polymers to adhere to mucosal membranes in the human body and provide a temporary retention. It has been widely used to develop polymeric dosage forms for buccal, oral, nasal, ocular and vaginal drug delivery. Excellent mucoadhesive proporties are typical for some water-soluble polymers that are capable to interact with mucins specifically via hydrogen bonding, electrostatic attraction and hydrophobic effects. This experiment will probe the structural changes occuring with porcine gastric mucin as a result of its specific interactions with poly(acrylic acid) and polyethyleneglycol.