Differential scanning calorimetry study on drug release from an inulin-based hydrogel and its interaction with a biomembrane model: pH and loading effect.
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.
Castelli
Francesco
F
Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale Andrea Doria 6, 95125 Catania, Italy. fcastelli@dipchi.unict.it
Sarpietro
Maria Grazia
MG
Micieli
Dorotea
D
Ottimo
Sara
S
Pitarresi
Giovanna
G
Tripodo
Giuseppe
G
Carlisi
Bianca
B
Giammona
Gaetano
G
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
D000894:Anti-Inflammatory Agents, Non-Steroidal; D020100:Hydrogels; D007004:Hypoglycemic Agents; D008567:Membranes, Artificial; D013386:Succinates; D004061:Diflunisal; D007444:Inulin; D007339:Insulysin; D004134:Dimyristoylphosphatidylcholine