title: Growth and shrinkage of pluronic micelles by uptake and release of flurbiprofen: variation of pH.
abstract: The micellization of Pluronic triblock copolymers (P103, P123, and L43) in the presence of flurbiprofen at different pH was studied by small-angle neutron scattering (SANS), pulsed-field gradient stimulated-echo nuclear magnetic resonance (PFGSE-NMR), and surface tension measurements. Addition of flurbiprofen to the Pluronic at low pH leads to an increase in the fraction of micellization, aggregation number, and the core radius of the micelles. However, changing the pH to above the pKa of flurbiprofen in an ethanol/water mixture (∼6.5) reduces the fraction of micellization and results in a weaker interaction between the drug and micelles due to the increased drug solubility in aqueous solution.
authors.affiliation: School of Chemistry, University of Bristol , Bristol BS8 1TS, U.K.
authors.forename: Shirin
authors.initials: S
authors.lastname: Alexander
authors.forename: Wiebe M
authors.initials: WM
authors.lastname: de Vos
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Castle
authors.forename: Terence
authors.initials: T
authors.lastname: Cosgrove
authors.forename: Stuart W
authors.initials: SW
authors.lastname: Prescott
mesh_terms: D005480:Flurbiprofen / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D008958:Models, Molecular; D015394:Molecular Structure; D011060:Poloxalene; D011108:Polymers / Q000737:chemistry*; D013500:Surface Tension
chemical_list: D008823:Micelles; D011108:Polymers; C464484:pluronic block copolymer P123; D005480:Flurbiprofen; D011060:Poloxalene