title: Lactitol-based poly(ether polyol) hydrogels for controlled release chemical and drug delivery systems.
abstract: The hydroxyl groups of lactitol were propoxylated to produce poly(ether polyol) (LPEP). The average pK(a) value of hydroxyl groups of the polyol was 1.63. Cross-linked hydrogels were synthesized by esterification with chlorinated poly(ethylene glycol) bis(carboxymethyl) ether (PEGBCOCl). The swelling ratio decreased with increasing cross-linking ratio (PEGBCOCl:LPEP) from 2:1 to 4:1 in the hydrogels and was sensitive to temperature change between 25 and 55 degrees C and concentrations of salt and glucose. The swelling ratio did not change significantly with pH in the range of 4-9. The release profiles of a model active agent, acetylsalicylic acid, from the hydrogels showed that the diffusional release rate had a half-order dependence on time, and the diffusivity decreased with increasing cross-linking ratio. This work demonstrated that LPEP-based hydrogels can be used for controlled delivery of drugs and agrochemicals and the release rates can be controlled with the cross-linking ratio of the hydrogel.
authors.affiliation: Department of Food Science and Technology, University of California, Davis, California 95616, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Han
authors.forename: J M
authors.initials: JM
authors.lastname: Krochta
authors.forename: M J
authors.initials: MJ
authors.lastname: Kurth
authors.forename: Y L
authors.initials: YL
authors.lastname: Hsieh
mesh_terms: D001241:Aspirin; D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D020100:Hydrogels / Q000138:chemical synthesis; D007700:Kinetics; D011108:Polymers; D013402:Sugar Alcohols
chemical_list: D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D020100:Hydrogels; D011108:Polymers; D013402:Sugar Alcohols; C024617:polyol; C014635:lactitol; D001241:Aspirin