A Thermo-Sensitive Hydrogel: Poly(ethylene oxide-dimethyl siloxane-ethylene oxide)/Poly(N-isopropyl acrylamide) Interpenetrating Polymer Networks II. On-Off Regulation of Solute Release from Thermo-Sensitive Hydrogel

Abstract

ABSTRACT:Interpenetrating polymer networks (lPNs) of poly(ethylene oxide-dimethyl siloxane-ethylene oxide) (PEO-PDMS-PEO) ABA triblock copolymer and poly(N-isopropyl acrylamide) (PIPAAm) has been synthesized as thermosensitive gels. Indomethacin andketoprofen were selected as model drugs and incorporated into thermosensitive gel. Pulsatile drug release produced from these thermosensitive gels was strongly influenced bytheswelling-deswelling kinetic properties of thermosensitive gels solubility dependence of drug as a function of temperature, and thetemperature applied. However, therelease behavior ofindomethacin andketoprofen at several fixed temperatures from the thermosensitive gel showed similar patterns. The exact initiation temperatures fordrug release of both drugs were similar andslightly below theswelling transition temperature of an unloaded gel.KEY WORDS Indomethacin / Ketoprofen / Pulsatile Drug Release / Solubility Dependence / Swelling Transition Temperature / Phase Continuity / Morphology / Swelling-Deswelling Kinetic / It is important to control drug release from delivery devices in order to produce a zero order release rate of sustained release. Therapeutically, the advantages of controlled release are ability to maintain drug levels constantly within an effective blood concentration range, to administer less drug to produce effective therapy and less frequent administration than with conventional dosage forms.Many efforts have been made to create new controlled release methods that sometimes emphasize the use of polymer.

UCST-Type Cononsolvency Behavior of Poly(2-methacryloxyethyl phosphorylcholine) in the Mixture of Water and Ethanol

“…12,13 The cononsolvency behavior of PNIPAM is used for the controlled release of alcohol soluble drugs from a thermosensitive gel consisting of interpenetrating polymer networks of PNIPAM and a triblock copolymer. 14 Kiritoshi and Ishihara 15 synthesized crosslinked PMPC gel and measured its strange swelling and shrinking behavior in the mixtures of water and ethanol caused by the cononsolvency of PMPC in water and ethanol.…”

Preparation and characterization of polysiloxane‐acrylate latexes with MPS‐PDMS oligomer as macromonomer

“…9,10 It is well known that within a proper range, the more siloxane in the copolymer, the more excellent properties of siloxane would be embodied, so the question of how to enhance the siloxane content in latexes is becoming more and more important. The most widely used method of introducing polysiloxane into the latexes is the group of SiAOH (caused by the hydrolysis of Si(OCH 3 ) 3 groups in the main chain) initiating the ring opening polymerization of D 4 , that is to say the hydrolysis and the ring opening polymerization happened at the same time.…”

Glutaraldehyde-crosslinked poly(glycidol-block-ethylene oxide-block-glycidol) networks with temperatureresponsive swelling behaviour

“…To modulate the temperature behaviour of PEO macromolecules, hydrophobic groups or segments have to be introduced [20][21][22][23][24]. PEO-containing thermosensitive materials are obtained via crosslinking of EO copolymers with another thermosensitive [25][26][27] 1 or hydrophobic polymer [6,28] or by mixing PEO with a second thermosensitive polymer [28,29]. The lack of reactive functional groups in the PEO chains, except for the end groups, makes proper adjustment of the hydrophilic-hydrophobic balance difficult.…”