On Interactions of Sulfamerazine with Cyclodextrins from Coupled Diffusometry and Toxicity Tests.

This scientific study employs the Taylor dispersion technique for diffusion measurements to investigate the interaction between sulfamerazine (NaSMR) and macromolecular cyclodextrins (-CD and HP--CD). The results reveal that the presence of -CD influences the diffusion of the solution component, NaSMR, indicating a counterflow of this drug due to solute interaction. However, diffusion data indicate no inclusion of NaSMR within the sterically hindered HP--CD cavity.

Interactions of Sodium Salicylate with β-Cyclodextrin and an Anionic Resorcin[4]arene: Mutual Diffusion Coefficients and Computational Study.

The interaction between sodium salicylate (NaSal) and the two macrocycles 5,11,17,23-tetrakissulfonatomethylene-2,8,14,20-tetra(ethyl)resorcinarene (NaEtRA) and β-cyclodextrin (β-CD) has been studied by the determination of ternary mutual diffusion coefficients, and spectroscopic and computational techniques. The results obtained by the Job method suggest that the complex formation is given in a 1:1 ratio for all systems. The mutual diffusion coefficients and the computational experiments have shown that the β-CD-NaSal system presents an inclusion process, whereas the NaEtRA-NaSal system forms an outer-side complex.

Interactions between Sodium Hyaluronate and β-Cyclodextrin as Seen by Transport Properties.

Knowledge of mass transport parameters, diffusion, and viscosity of hyaluronic acid (HA) in the presence of cyclodextrins is of considerable importance for areas such as food packaging and drug delivery, among others. Despite a number of studies investigating the functionalization of HA or the corresponding sodium salt by cyclodextrins, only a few studies have reported the effect of cyclodextrins on the mass transport of HA in the presence of these oligosaccharides. Here, we report the tracer binary and ternary interdiffusion coefficients of sodium hyaluronate (NaHy) in water and aqueous β-cyclodextrin solutions.

Diffusion of Vanadium Ions in Artificial Saliva and Its Elimination from the Oral Cavity by Pharmacological Compounds Present in Mouthwashes.

In this study, diffusion coefficients of ammonium vanadate at tracer concentrations in artificial saliva with and without sodium fluoride, at different pH values, were measured using an experimental model based on the Taylor dispersion technique. Ternary mutual diffusion coefficients (, , , and ) for four aqueous systems {NHVO (component 1) + β-cyclodextrin (β-CD) (component 2),} {NHVO (component 1) + β-cyclodextrin (HP-β-CD) (component 2)}, {NHVO (component 1) + sodium dodecyl sulphate (SDS) (component 2)} and {NHVO (component 1) + sodium hyaluronate (NaHy) (component 2)} at 25.00 °C were also measured by using the same technique.

Complexation of 5-Fluorouracil with -Cyclodextrin and Sodium Dodecyl Sulfate: A Useful Tool for Encapsulating and Removing This Polluting Drug.

The formation of complexes of the drug 5-fluorouracil (5-FU) with -cyclodextrin (-CD) and sodium dodecyl sulphate (SDS) was studied through experimental measurements of the ternary mutual diffusion coefficients (, , , and ) for the systems {5-FU (component 1) + -CD (component 2) + water} and {5-FU (component 1) + SDS (component 2) + water} at 298.15 K and at concentrations up to 0.05 mol dm by using the Taylor dispersion method, with the objective of removing this polluting drug from the residual systems in which it was present.

Effect of Cobalt and Chromium Ions on the Chlorhexidine Digluconate as Seen by Intermolecular Diffusion.

Metal ions such as cobalt (II) and chromium (III) might be present in the oral cavity, as a consequence of the corrosion of Co-Cr dental alloys. The diffusion of such metal ions into the organism, carried by saliva, can cause health problems as a consequence of their toxicity, enhanced by a cumulative effect in the body. The effect of the chlorhexidine digluconate, which is commonly used in mouthwash formulations, on the transport of these salts is evaluated in this paper by using the Taylor dispersion technique, which will allow an assessment of how the presence of chlorhexidine digluconate (either in aqueous solution or in a commercial formulation) may affect the diffusion of metal ions.

Transport properties in aqueous ethambutol dihydrochloride.

Mutual diffusion coefficients, densities and viscosities are reported for aqueous solutions of ethambutol as its dihydrochloride (EMBDHC) at finite concentrations and at 298.15K. From these experimental results and by using the appropriate models (Stokes-Einstein and Hartley), the hydrodynamic radii Rh, the diffusion coefficient at infinitesimal concentration D(0) and the thermodynamic factors, FT, have been estimated, permitting us to have a better understanding of the transport behavior of ethambutol dihydrochloride in solution.

Mass transport techniques as a tool for a better understanding of the structure of L-Dopa in aqueous solutions.

Mutual diffusion coefficients, D, densities, ρ, and viscosities, η, are reported for aqueous solutions of L-3,4-dihydroxyphenylalanine (L-Dopa) at 298.15K and 310.15K at concentrations from (0.

Effect of HP-β-cyclodextrin in the diffusion behaviour of hydrocortisone in aqueous solutions at T=298.15 K.

Binary (D) and ternary (D(11), D(22), D(12) and D(21)) mutual diffusion coefficients determined by the Taylor dispersion method are reported for two aqueous systems, pure hydrocortisone (HC/H(2)O) and HC plus HP-β-cyclodextrin (HC/HP-βCD/H(2)O), at T=298.15 K. From these data, some thermodynamic information as well as conclusions about the influence of that carbohydrate in the diffusion of this drug are given.

Calculations of Diffusion Coefficients of Iron Salts in Aqueous Solutions at 298.15 K: A Useful Tool for the Knowledge of the Structure of these Systems.

Diffusion coefficients, thermodynamic and mobility factors of iron salts in aqueous solutions are estimated from Onsager-Fuoss model. The influence of the ion size parameter a, "mean distance of closest approach of ions", determined from different approaches, on the variation of diffusion coefficients with concentration, is also discussed. The aim of this work is to have a better understanding of the structure of these systems and of the thermodynamic behaviour of iron salts in aqueous media.