title: pH-sensitive hydrogel based on a novel photocross-linkable copolymer.
abstract: A pH sensitive hydrogel has been prepared by a UV irradiation technique. Starting polymer was the PHM (poly hydroxyethylaspartamide methacrylated) obtained from polyaspartamide (PHEA) partially derivatized with methacrylic anhydride (MA). This new copolymer has been further derivatized with succinic anhydride (SA) to obtain PHM-SA that has been cross-linked by UV irradiation to form a pH sensitive hydrogel. The network, recovered after washing as a powder, has been been characterized by FT-IR spectrophotometry and particle size distribution analysis. Moreover, to have information about water affinity of the prepared sample, swelling measurements have been carried out in aqueous media mimicking biological fluids. The possibility to employ the prepared hydrogel as a pH-sensitive drug delivery system (DDS) has been investigated. In particular, ibuprofen ((S)(+)4-isobutyl-alpha-methylphenyl-acetic acid), chosen as a model drug, has been entrapped into the PHM-SA hydrogel, and in vitro release studies have showed that its release rate depends on different swelling of the network as a function of the environmental pH.
authors.affiliation: Dipartimento di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi n.32, 90123, Italy.
authors.forename: Delia
authors.initials: D
authors.lastname: Mandracchia
authors.forename: Giovanna
authors.initials: G
authors.lastname: Pitarresi
authors.forename: Fabio S
authors.initials: FS
authors.lastname: Palumbo
authors.forename: Bianca
authors.initials: B
authors.lastname: Carlisi
authors.forename: Gaetano
authors.initials: G
authors.lastname: Giammona
mesh_terms: D003432:Cross-Linking Reagents / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D020100:Hydrogels / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D006863:Hydrogen-Ion Concentration; D011108:Polymers / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D003432:Cross-Linking Reagents; D020100:Hydrogels; D011108:Polymers