title: Clonazepam release from core-shell type nanoparticles of poly(epsilon-caprolactone)/poly(ethylene glycol)/poly(epsilon-caprolactone) triblock copolymers.
abstract: The triblock copolymer based on poly(epsilon-caprolactone) (PCL) as hydrophobic part and poly(ethylene glycol) (PEG) as hydrophilic one was synthesized and characterized. Core-shell type nanoparticles of poly(epsilon-caprolactone)/poly(ethylene glycol)/poly(epsilon-caprolactone) (CEC) block copolymer were prepared by a dialysis technique. According to the amphiphilic characters, CEC block copolymer can self-associate at certain concentration and their critical association concentration (CAC) was determined by fluorescence probe technique. CAC value of the CEC-2 block copolymer was evaluated as 0.0030 g/l. CAC values of CEC block copolymer decreased with the increase of PCL chain length, i.e. the shorter the PCL chain length, the higher the CAC values. From the observation of transmission electron microscopy (TEM), the morphologies of CEC-2 core-shell type nanoparticles were spherical shapes. Particle size of CEC-2 nanoparticles was 32.3+/-17.3 nm as a monomodal and narrow distribution. Particle size, drug loading, and drug release rate of CEC-2 nanoparticles were changed by the initial solvents and the molecular weight of CEC. The degradation behavior of CEC-2 nanoparticles was observed by 1H NMR spectroscopy. It was suggested that clonazepam (CNZ) release kinetics were dominantly governed by diffusion mechanism.
authors.affiliation: College of Pharmacy, Chosun University, #375 Seosuk-Dong, Dong-Gu, 501-759, Kwangju, South Korea.
authors.forename: J
authors.initials: J
authors.lastname: Ryu
authors.forename: Y I
authors.initials: YI
authors.lastname: Jeong
authors.forename: I S
authors.initials: IS
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.forename: J W
authors.initials: JW
authors.lastname: Nah
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
mesh_terms: D002998:Clonazepam / Q000008:administration & dosage / Q000737:chemistry*; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D009682:Magnetic Resonance Spectroscopy; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D011091:Polyesters; D011108:Polymers; C016240:polycaprolactone; D011092:Polyethylene Glycols; D002998:Clonazepam