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.
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http://dx.doi.org/10.1021/la204262w | DOI Listing |
J Pharm Sci
December 2024
Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark. Electronic address:
Physiological and artificial solubilizing agents usually enhance apparent solubility of poorly soluble drugs, and in many cases also oral drug exposure. However, exposure may decrease in cases where micellization reduces the molecularly dissolved drug fraction, overriding the solubility advantage. While this information is critical to accurately anticipate the effect of drug micellization on oral absorption, the experimental determination of molecularly dissolved drug concentrations is complex and time consuming.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Department of Medicinal Chemistry, Uppsala University, P.O. Box 547, 751 23, Uppsala, Sweden. Electronic address:
We have investigated the effect of length and chemical structure of phospholipid tails on the spontaneous formation of unilamellar liposomal vesicles in binary solute mixtures of cationic drug surfactant and zwitterionic phosphatidylcholine phospholipids. Binary drug surfactant-phospholipid mixtures with four different phospholipids with identical headgroups (two saturated phospholipids 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC, 14:0) and 1,2-Dipalmitoyl-sn-glycero-3-phosphocholine (DPPC, 16:0), and two unsaturated lipids 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC, 18:1) and 1,2-Dierucoyl-sn-Glycero-3-Phosphatidylcholine (DEPC, 22:1)) combined with two different tricyclic antidepressant drugs (amitriptyline hydrochloride (AMT) and doxepin hydrochloride (DXP)) have been investigated with small-angle neutron scattering (SANS) and cryo-transmission electron microscopy (cryo-TEM). We observe a conspicuous impact of phospholipid tail structure on both micelle-to-vesicle transition point and vesicle size.
View Article and Find Full Text PDFExtracell Vesicles Circ Nucl Acids
May 2024
MILCH and Novel Therapeutics Lab, Division of Epidemiology, Department of Environmental and Public Health Sciences, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
This study aimed to systematically compare four casein micelle removal methods on the particle and protein characteristics of the isolated human milk EVs. The defatted milk was treated with 1% sodium citrate, 20 mM ethylenediaminetetraacetic acid (EDTA), 1% acetic acid, or 1% chymosin/calcium chloride for 30 min at 4 °C to remove casein micelles. EV isolation was performed using qEV size exclusion chromatography.
View Article and Find Full Text PDFFood Chem
December 2024
Human Nutrition Program, The Ohio State University, Columbus, OH 43210, United States; Foods for Health Discovery Theme, The Ohio State University, Columbus, OH 43210, United States. Electronic address:
Previous results have been mixed as to whether the emulsifying agent lecithin increases carotenoid bioaccessibility and Caco-2 cellular uptake. The dose-response effect of lecithin (0-5 mg) on carotenoid bioaccessibility and Caco-2 cellular uptake was investigated in vitro using a mixture of β-carotene, lycopene, lutein, zeaxanthin and astaxanthin. Resulting micelles were incubated with Caco-2 cells for 4 h.
View Article and Find Full Text PDFFoods
November 2024
Midwest Dairy Foods Research Center, Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108, USA.
The influence of heating as a pretreatment on the structural and functional attributes of milk protein concentrate (MPC) powders derived from ultrafiltered/diafiltered (UF/DF) skim milk is under-reported. This research delves into the impact of pH and heat treatment on skim milk's properties before UF/DF and how these changes affect the resulting MPC powders. By adjusting the pH of skim milk to 6.
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