The mechanism of drug release from swellable polymer was studied. The model which can explain the drug release from glassy polymer was developed by coupling drug diffusion equation and solvent diffusion equation. The effect of viscoelastic stress of polymer was also considered. The Deborah number and swelling interface number were used to describe the mechanism of drug release, especially relax controlled mechanism.
Delayed-Action Preparations ; Diffusion ; Drug Delivery Systems ; Models, Chemical ; Polymers ; chemistry ; Tablets

Sugar-containing monomer vinylbenzylglycosylallyamide (VBG) was synthesized by vinylbenzyl amine and delta-gluconolactone in dimethylformamide(DMF) solution. The sugar-based hydrogel was prepared by free radical crosslinking copolymerization of VBG, itaconic acid (IA) and acrylamide (AM). The release properties of Aspirin from xerogels matrices and from hydrogel in different pH solutions and different concentration NaCl solutions were studied respectively. The release mechanism of Aspirin was further confirmed by evaluating the n value in Peppas equation. The results indicated that the drug release increased with the increase of pH values and with the decrease of NaCl concentration.
Acrylic Resins ; chemistry ; Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; chemistry ; Aspirin ; administration & dosage ; chemistry ; Delayed-Action Preparations ; chemical synthesis ; chemistry ; Humans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemical synthesis ; chemistry ; Hydrogen-Ion Concentration ; Succinates ; chemistry ; Vinyl Compounds ; chemistry

Sugar-containing monomer glycosylallylamide (AAG) was synthesized by allyl amine and delta-gluconolactone in dimethylformamide (DMF) solution. The sugar-based hydrogels were prepared by free radical crosslinking copolymerization of AAG and acrylamide (AM). The release properties of Aspirin from xerogels matrices were studied and the release mechanism of Aspirin was further identified by evaluating the n value in Peppas equation. The results indicate that the drug release decreases with the increase of the sugar content of hydrogel.
Acrylamide ; chemical synthesis ; chemistry ; Aspirin ; pharmacokinetics ; Delayed-Action Preparations ; Gluconates ; chemical synthesis ; chemistry ; Hydrogels ; chemical synthesis ; chemistry ; Lactones ; Polymers ; chemical synthesis ; chemistry