Drug delivery systems contact time

Swelling is one of the functional properties used to characterize biopolymers required for modified or controlled drug delivery systems. The biopolymers employed for modified drug delivery applications are hydrogels that form three-dimensional polymeric networks when they come into contact with water, they absorb many times their weight of water but they do not dissolve. Swelling of the ceUulosics in different biorelevant media must be established. 

There is a tendency in ophthalmic drug delivery systems towards a combination of several drug delivery technologies to achieve not only prolonged contact time of the vehicle at the ocular surface, but also to slow down the elimination of the drug, so improving therapeutic response. 

---