Title : HEA-HEMA hydrogels: Composition effect on physicochemical and pharmaceutical properties
Abstract:
Hydrogels have attracted considerable attention due to their capability to be used for numerous pharmaceutical and biomedical applications (i.e. drug delivery systems, contact lenses and wound dressings). Hydrogels are swellable polymeric materias capable of imbibing a large amount of liquid and, therefore, a large amount of drug. Recently we have described novel cross-linked 2-hydroxyethylacrylate-co-2-hydroxyethylmethacrylate (HEA-HEMA) hydrogels with different co-polymer compositions synthesized by three-dimensional free-radical copolymerisation. The aim of the present work is to characterize the physicochemical and pharmaceutical properties of HEA-HEMA hydrogels, which potentially can be used as sustain drug delivery systems. The effects of the hydrogel composition (HEA/HEMA ratios) and liquid medium (aqueous PEG and glycerol solutions) on morphology, swelling and mechanical properties were examined using different analytical techniques. The molecular dynamics results for hydrogels were obtained by Broadband Dielectric Spectroscopy. The current study has been specifically focused on the analysis of the free/bound water redistribution in the hydrogels using thermoanalytical techniques. Also the effect of different methods of sterilization was studied with respect to the stability of hydrogels. The pramaceutical aspect of this study included the analysis of drug loading and release for the cases of low molecular weigth drugs (riboflavin) and proteins (lysozyme). The results show that HEA-HEMA hydrogels can be used as a sustain drug delivery system for both small drugs and biomacromolecules. The variation of the HEA-HEMA composition as well as liquid medium permits controlling the properties of hydrogels allowing producing the hydrogels with the drug release rate desired.
