The investigators propose to develop and study the mucoadhesive behavior of hydrophilic polymer drug carriers that are modified by the addition of polyethylene glycols, as further described by their abstract: """"""""The primary goal of bioadhesive controlled drug delivery is to localize a delivery device within the body to enhance the drug absorption process in a site-specific manner. Bioadhesion is affected by the synergistic action of the biological environment, the properties of the polymeric controlled release device, and the presence of the drug itself. The delivery site and the device designed are dictated by the drug's molecular structure and its pharmacological behavior. Recent studies in our laboratory indicate that the mucoadhesive behavior of specific hydrophilic polymer structures used as carriers for drug delivery can be improved with the addition of poly(ethylene glycol) (PEG) as an adhesion promoter. PEG chains can be added to such structures by post-reaction grafting leading to PEG-tethered hydrogels. An additional method is by loading PEG into an already swollen hydrogel structure. In the present work we develop, characterize and evaluate new drug delivery systems containing PEG."""""""" """"""""The fracture energy required to separate layers of hydrogel films in control with mucin is investigated to evaluate the impact of promoter chain diffusion on device/mucin adhesion and to obtain molecular information on the fracture energy in drug carrier mucoadhesion. PEG is incorporated in a hydrogel and used as an adhesion promoter. The influence of PEG molecular weight and contact time on PEG diffusion across the hydrogel/mucin interface is investigated by using tensiometry and near-field FTIR microscopy. Fracture analysis provides details about the mechanism of muco-adhesion and conditions of improved adhesion. In our work, we concentrate also on the practical development of such PEG-tethered or PEG-promoted systems for transmucosal, buccal and nasal delivery systems.""""""""
