Mucoadhesive hydrogels properties

The mucoadhesive properties of several classes of hydrogels have been identified, and two types of polymers have attracted special attention. Polyacrylates and their cross-linked modifications represent the anionic type, chitosan and its derivatives the cationic group. In addition, both types of polymers show a number of interesting characteristics beneficial for the administration of a wide range of therapeutics. 

Polyethylene oxide has been shown to be an excellent mucoadhesive polymer. Low levels of polyethylene oxide are effective thickeners, although alcohol is usually added to water-based formulations to provide improved viscosity stability see Table II. Polyethylene oxide films demonstrate good lubricity when wet. This property has been utilized in the development of coatings for medical devices. Polyethylene oxide can be radiation crosslinked in solution to produce a hydrogel that can be used in wound care applications. 

The above mentioned effects suggest the possible use of S. sclarea oil in the stomatological field to treat infective conditions which are often accompanied by inflammation. Since anti-inflammatory and analgesic effects require some drug absorption, some research [56-57] has been done recently to evaluate the capacity of the essential oil components to permeate the oral mucous in various mucoadhesive formulations of the oil (microemulsions, hydrogels and gelled microemulsions), useful in local treatments of stomatological ailments. The permeation properties of the... 

The improvement in residence time of ophthalmic semisolid hydrogels is primarily based on an increase in ocular residence time as a result of a reduction in drainage rate through enhanced viscosity and mucoadhesive properties. 

From a methodology point of view, the reological approach involves the investigation of the changes in rheological properties that mucoadhesive PE and hydrogels undergo when they are mixed with mucins. 

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