title: Design and synthesis of pH-sensitive polymeric micelles for oral delivery of poorly water-soluble drugs.
abstract: pH-sensitive polymer poly (polylactide-co-methacrylic acid)-b-poly (acrylic acid) was synthesized using atom transfer radical polymerization and ring-opening polymerization and characterized by gel permeation chromatography and (1)H NMR. The polymers can self-assemble to form micelles in aqueous medium, which respond rapidly to pH change within the gastrointestinal relevant pH range. Critical micelle concentrations and pH response behavior of the polymeric micelle were investigated. Water-insoluble drug nifedipine was loaded and the drug-loading content can be controlled by tuning the composition of the polymers. The in vitro release studies indicate pH sensitivity enabled rapid drug release at the environment of simulated intestinal fluid (pH 7.36), the cumulative released amount of NFD reached more than 80% within 24 h, while only 35% in the simulated gastric fluid (pH 1.35). All the results showed that the pH-sensitive P(PLAMA-co-MAA)-b-PAA micelle may be a prospective candidate as oral drug delivery carrier for hydrophobic drugs with controlled release behavior.
authors.affiliation: a State Key Laboratory of Organic-Inorganic Composites , Beijing University of Chemical Technology , Beijing , People's Republic of China.
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Yang
authors.affiliation: a State Key Laboratory of Organic-Inorganic Composites , Beijing University of Chemical Technology , Beijing , People's Republic of China.
authors.forename: Rongrong
authors.initials: R
authors.lastname: Fan
authors.affiliation: a State Key Laboratory of Organic-Inorganic Composites , Beijing University of Chemical Technology , Beijing , People's Republic of China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Wang
authors.affiliation: a State Key Laboratory of Organic-Inorganic Composites , Beijing University of Chemical Technology , Beijing , People's Republic of China.
authors.forename: Jiexin
authors.initials: J
authors.lastname: Wang
authors.affiliation: a State Key Laboratory of Organic-Inorganic Composites , Beijing University of Chemical Technology , Beijing , People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Le
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D065546:Drug Liberation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008823:Micelles; D009543:Nifedipine / Q000737:chemistry*; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D058105:Polymerization; D012995:Solubility; D014867:Water
chemical_list: D000180:Acrylic Resins; D004337:Drug Carriers; D008823:Micelles; D011091:Polyesters; D014867:Water; D009543:Nifedipine
keywords: oral administration; pH-sensitive; polymeric micelles