title: Differential scanning calorimetry study on drug release from an inulin-based hydrogel and its interaction with a biomembrane model: pH and loading effect.
abstract: Inulin has been derivatized with methacrylic anhydride (MA) and succinic anhydride (SA) to obtain a methacrylated/succinilated derivative (INU-MA-SA) able to produce a pH sensitive hydrogel after UV irradiation. The hydrogel was characterized and loaded with diflunisal (10.4, 17 and 24%, w/w) chosen as a model drug. The drug release from INU-MA-SA-based hydrogel to a biomembrane model made by unilamellar vesicles of dimyristoylphosphatidylcholine (DMPC) was investigated at pH 4.0 and 7.4 by differential scanning calorimetry (DSC) that appears to be a suitable technique to follow the transfer kinetics of a drug from a controlled release system to a biomembrane model. The drug release from the hydrogel was compared with the dissolution of drug solid form by examining the effects exerted on the thermotropic behaviour of the DMPC unilamellar vesicles. The transferred drug and the release rate were affected by the drug loading as well as by the pH of the external medium. In particular the release was not linearly related to the drug loading but an intermediate loading allowed a better release at both investigated pHs, with a faster and more complete release observed at pH 7.4.
authors.affiliation: Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale Andrea Doria 6, 95125 Catania, Italy. fcastelli@dipchi.unict.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Castelli
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Sarpietro
authors.forename: Dorotea
authors.initials: D
authors.lastname: Micieli
authors.forename: Sara
authors.initials: S
authors.lastname: Ottimo
authors.forename: Giovanna
authors.initials: G
authors.lastname: Pitarresi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Tripodo
authors.forename: Bianca
authors.initials: B
authors.lastname: Carlisi
authors.forename: Gaetano
authors.initials: G
authors.lastname: Giammona
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D002498:Centrifugation; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004061:Diflunisal / Q000737:chemistry; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000737:chemistry; D007339:Insulysin / Q000737:chemistry; D007444:Inulin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008567:Membranes, Artificial; D008970:Molecular Weight; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013386:Succinates / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D020100:Hydrogels; D007004:Hypoglycemic Agents; D008567:Membranes, Artificial; D013386:Succinates; D004061:Diflunisal; D007444:Inulin; D007339:Insulysin; D004134:Dimyristoylphosphatidylcholine