Transport properties of nonelectrolyte liquid mixtures. X. Limiting mutual diffusion coefficients of fluorinated benzenes inn-hexane

1996 ◽  
Vol 17 (4) ◽  
pp. 759-769 ◽  
Author(s):  
M. A. Awan ◽  
J. H. Dymond
Keyword(s):  
Transport Properties ◽  
Diffusion Coefficients ◽  
Liquid Mixtures ◽  
Mutual Diffusion

scholarly journals Transport Properties for Pharmaceutical Controlled-Release Systems: A Brief Review of the Importance of Their Study in Biological Systems

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 178 ◽  
Author(s):  
Ana C. F. Ribeiro ◽  
Miguel A. Esteso
Keyword(s):  
Controlled Release ◽  
Transport Properties ◽  
Diffusion Coefficients ◽  
Drug Carrier ◽  
Strong Association ◽  
Mutual Diffusion ◽  
Mixed Electrolytes ◽  
Coupled Transport ◽  
Concentration Gradients ◽  
Enhanced Solubility

: The goal of this work was to comprehensive study the transport properties of controlled-release systems for the safe and reliable delivery of drugs. Special emphasis has been placed on the measurement of the diffusion of drugs, alone or in combination with carrier molecules for enhanced solubility and facilitated transport. These studies have provided detailed comprehensive information—both kinetic and thermodynamic—for the design and operation of systems for the controlled release and delivery of drugs. Cyclodextrins are among the most important carriers used in these systems. The basis for their popularity is the ability of these materials to solubilize poorly soluble drugs, generally resulting in striking increases in their water solubilities. The techniques used in these investigations include pulse voltammetry, nuclear magnetic resonance (NMR) and Raman spectroscopy, ultrasonic relaxation, and dissolution kinetics. Transport in these systems is a mutual diffusion process involving coupled fluxes of drugs and carrier molecules driven by concentration gradients. Owing to a strong association in these multicomponent systems, it is not uncommon for a diffusing solute to drive substantial coupled fluxes of other solutes, mixed electrolytes, or polymers. Thus, diffusion data, including cross-diffusion coefficients for coupled transport, are essential in order to understand the rates of many processes involving mass transport driven by chemical concentration gradients, as crystal growth and dissolution, solubilization, membrane transport, and diffusion-limited chemical reactions are all relevant to the design of controlled-release systems. While numerous studies have been carried out on these systems, few have considered the transport behavior for controlled-release systems. To remedy this situation, we decided to measure mutual diffusion coefficients for coupled diffusion in a variety of drug–carrier solutions. In summary, the main objective of the present work was to understand the physical chemistry of carrier-mediated transport phenomena in systems of controlled drug release.

Mutual diffusion coefficients in some binary liquid mixtures

1987 ◽  
Vol 32 (1) ◽  
pp. 48-50 ◽  
Author(s):  
Mohammad Aslam Siddiqi ◽  
Werner Krahn ◽  
Klaus Lucas
Keyword(s):  
Diffusion Coefficients ◽  
Liquid Mixtures ◽  
Binary Liquid Mixtures ◽  
Mutual Diffusion ◽  
Binary Liquid

The mutual diffusion coefficient of ethanol–water mixtures: determination by a rapid, new method

1974 ◽  
Vol 336 (1606) ◽  
pp. 393-406 ◽  
Keyword(s):  
Experimental Data ◽  
Diffusion Coefficient ◽  
Laminar Flow ◽  
Diffusion Coefficients ◽  
Entire Range ◽  
Liquid Mixtures ◽  
Mutual Diffusion ◽  
Mutual Diffusion Coefficient ◽  
Mechanical Theory ◽  
Statistical Mechanical

Mutual diffusion coefficients for liquid mixtures of ethanol and water have been measured over the entire range of composition and for temperatures from 25 to 65 °C at a pressure of 1 bar (10 5 Pa). At the lowest temperature, the results establish the validity of a new experimental method based upon Taylor’s analysis of solute dispersion in laminar flow. The method offers advantages of simplicity and speed over other techniques, and allows direct measurement of diffusion coefficients at well-defined mixture compositions. The experimental data have an estimated uncertainty of ±2.5% . The results have been utilized to evaluate friction coefficients arising in the statistical mechanical theory of transport in liquid mixtures.

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