h-point standard addition method (hpsam) was applied for the simultaneous determination of v(v) and fe(iii). the method is based on the complex formation of v(v) and fe(iii) with chromazurol s (cas) in acidic media and in the presence of cetyltrimethylammonium bromide (ctab) as a micellizing agent. acidic media and the presence of a micellar system improve selectivity and sensitivity. fe (iii) ...

Structural and dynamical properties of a micellar solution are studied mainly through examining its rheological behavior in the semidilute regime. The micellar solution is made of a zwitterionic surfactant N-tetradecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate, sodium dodecyl sulfate, and salty water. In particular, we are interested in how the system is affected when the ionic strength of the ...

Vitamin D is an essential nutrient with important immunomodulatory properties. As a fat-soluble compound, (and its D3 form) immiscible water, which presents challenges to absorption. In in vitro setting, the current study characterizes novel micellar formulations of designed improve Techniques used evaluate and compare against non-micellar formula include following: cryo-SEM determine morpholog...

In this work the acidity constants of Thiamine in water and water-Triton X-100 micelle media solutions, at 25 °C, have been determined spectrophotometrically. To evaluate the pH- absorbance data, a resolution based on the combination of soft-and hard-modeling is applied. The acidity constants of all related equilibria are estimated using the whole spectral fitting of the collected data to a...

The optical properties (absorption and fluorescence) of fluorescein sodium were investigated with changing the bulk pH value in aqueous, water-methanol mixed and dodecylammonium propionate reversed micellar solutions. A strong buffer action was found in the reversed micellar solutions. The pK a values for the equilibrium between fluorescein monoand di-anions in the ground and excited singlet st...

The relationship between intestinal bile acids and the micellar solubilization of lipids was studied by determining micellar bile acids and distribution of cholesterol and 0-sitosterol, their esters, and of hydrolysis products of triglycerides (labeled with H-tristearate), free fatty acids, monoglycerides and diglycerides between the micellar and oil phases of the intestinal contents for 1% h a...

The selection of media in dissolution method development can sometimes be an arbitrary decision. The case studies in this article give a practical rationale that should help in selecting media, especially surfactants. Three cases were studied: (1) the role of surfactants versus compound stability in the dissolution medium during dissolution method development, (2) the selection of a surfactant ...