title: pH- and temperature-sensitive release behaviors from polyelectrolyte complex films composed of chitosan and PAOMA copolymer.
abstract: This paper describes the pH and temperature effects on drug release from polyelectrolyte complex (PEC) films composed of a cationic polymer, chitosan, and an anionic polymer, polyalkyleneoxide-maleic acid copolymer (PAOMA). In this study, we prepared and investigated PEC films in terms of the drug release properties as pH- and temperature-sensitive drug carriers. Drug release rates were tested at pH 3.8 and 7.2, and at 25 and 50 degrees C. Salicylic acid and phenol were selected as model drugs. An increase in pH from 3.8 to 7.2 resulted in an increase in the rate of drug release because of the repulsive forces between carboxyl groups in PAOMA and anionic groups in model drugs. When the hydrophobic PAOMA was used as a polyanion, the drug release rate increased at 50 degrees C. This is attributed to the increase of release area due to the phase transition of PAOMA and the increase of repulsive forces between carboxyl groups in PAOMA and anionic groups in model drugs.
authors.affiliation: Department of International Development Engineering, Tokyo Institute of Technology, Tokyo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Yoshizawa
authors.forename: Yoshitsune
authors.initials: Y
authors.lastname: Shin-ya
authors.forename: Kyung-Jin
authors.initials: KJ
authors.lastname: Hong
authors.forename: Toshio
authors.initials: T
authors.lastname: Kajiuchi
mesh_terms: D048271:Chitosan / Q000737:chemistry / Q000493:pharmacokinetics*; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D008298:Maleates / Q000737:chemistry / Q000493:pharmacokinetics*; D008855:Microscopy, Electron, Scanning; D000071228:Polyelectrolytes; D011108:Polymers / Q000737:chemistry / Q000493:pharmacokinetics*; D011134:Polysaccharides / Q000737:chemistry / Q000493:pharmacokinetics / Q000648:ultrastructure; D013696:Temperature
chemical_list: D048271:Chitosan; D008298:Maleates; D000071228:Polyelectrolytes; D011108:Polymers; D011134:Polysaccharides; C030272:maleic acid