title: Release kinetics of hydrophobic and hydrophilic model drugs from pluronic F127/poly(lactic acid) nanoparticles.
abstract: Poly(lactic acid) (PLA) was successfully grafted to both ends of Pluronic F127 block copolymers (PEO-PPO-PEO) to obtain amphiphilic PLA-F127-PLA block copolymers. The block composition and structure of PLA-F127-PLA block copolymers were studied by nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), differential scanning calorimetric (DSC) and wide angle X-ray diffraction (WXRD) techniques. Data from DSC and WXRD measurements indicated that Tg and Tm of PLA blocks in PLA-F127-PLA block polymers are lower than those of PLA homopolymer. Furthermore, Tm and crystallinity of PLA blocks decrease with decreasing PLA block length in PLA-F127-PLA block copolymers. The release behaviors of both hydrophobic 9-(methylaminomethyl)anthracene (MAMA) and hydrophilic procaine hydrochloride (PrHy) model drugs from PLA-F127-PLA nanoparticles with vesicular structure in PBS solution at 37 degrees C were examined by UV spectroscopy. The release kinetics of both MAMA and PrHy model drugs from PLA-F127-PLA nanoparticles exhibit burst release characteristics, which are believed to be controlled by concentration gradient resulting from the slow hydrolytic degradation of PLA segments.
authors.affiliation: School of Mechanical and Production Engineering, Nanyang Technological University 639798, Singapore.
authors.forename: X Y
authors.initials: XY
authors.lastname: Xiong
authors.forename: K C
authors.initials: KC
authors.lastname: Tam
authors.forename: L H
authors.initials: LH
authors.lastname: Gan
mesh_terms: D057927:Hydrophobic and Hydrophilic Interactions; D019344:Lactic Acid / Q000493:pharmacokinetics*; D008956:Models, Chemical; D049329:Nanostructures; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D020442:Poloxamer / Q000493:pharmacokinetics*; D011091:Polyesters; D011108:Polymers / Q000493:pharmacokinetics*
chemical_list: D004364:Pharmaceutical Preparations; D011091:Polyesters; D011108:Polymers; D020442:Poloxamer; D019344:Lactic Acid; C033616:poly(lactide)