Probing drug solubilization patterns in the gastrointestinal tract after administration of lipid‐based delivery systems: A phase diagram approach

2004 ◽  
Vol 93 (2) ◽  
pp. 332-348 ◽  
Author(s):  
Greg A. Kossena ◽  
William N. Charman ◽  
Ben J. Boyd ◽  
Dave E. Dunstan ◽  
Christopher J.H. Porter
Keyword(s):  
Phase Diagram ◽  
Gastrointestinal Tract ◽  
Delivery Systems ◽  
Drug Solubilization ◽  
Diagram Approach

Calculation of physical properties of glass via the phase diagram approach

2017 ◽  
Vol 457 ◽  
pp. 36-43 ◽  
Author(s):  
Q.Y. Zhang ◽  
W.J. Zhang ◽  
W.C. Wang ◽  
Z.H. Jiang
Keyword(s):  
Phase Diagram ◽  
Physical Properties ◽  
Diagram Approach

DETERMINATION OF THE OPTIMAL CONCENTRATIONS OF PECTIN AND CALCIUM CHLORIDE FOR THE SYNTHESIS OF CHITOSAN-PECTIN MICROPARTICLES

2021 ◽  
Author(s):  
Alla Krasnoshtanova ◽  
Anastasiya Bezyeva
Keyword(s):  
Drug Delivery ◽  
Gastrointestinal Tract ◽  
Calcium Chloride ◽  
Active Substance ◽  
Drug Delivery Systems ◽  
Oral Drug Delivery ◽  
Oral Route ◽  
Delivery Systems ◽  
Oral Drug ◽  
Oral Drug Delivery Systems

"The oral route of drug inclusion is the most convenient for the patient. In addition to ease of use, this method of drug inclusion has such advantages as non-invasiveness of inclusion, absence of complications during injection; comparative safety for the organism due to the passage of the active substance and auxiliary compounds through the gastrointestinal tract; the possibility of introducing larger doses of the drug at one time. However, despite the obvious advantages, the oral route of inclusion has a number of significant disadvantages that significantly limit its use for a number of drugs. Among them are: relatively slow therapeutic action of the drug with this route of inclusion; the aggressive effect of a number of drugs (for example, antibiotics) on the gastrointestinal tract; low bioavailability of a number of substances (especially high molecular weight hydrophilic compounds), caused by poor permeability of the intestinal epithelium for hydrophilic and large molecules, as well as enzymatic and chemical degradation of the active substance in the gastrointestinal tract. There are various approaches used in the development of oral drug delivery systems. In particular, for the targeted delivery of drugs, it is proposed to use nano- and microcapsules with mucoadhesive properties. Among the polymers used for the synthesis of these microparticles, it is preferable to use pH-dependent, gelable biopolymers that change their structure depending on the acidity of the environment. Microcapsules obtained from compounds with the above properties are capable of protecting the active substance (or from the active substance) in the stomach environment and ensuring its release in the intestine. These properties are possessed by such polysaccharides as alginate, pectin, carrageenan, xylan, etc. The listed biopolymers are non-toxic, biocompatible, and biodegradable, which makes microparticles containing these polysaccharides promising as oral drug delivery systems. To impart mucoadhesive properties to nanoparticles, complexes of the listed polymers with chitosan are used. In this research, pectin, a polysaccharide formed mainly by residues of galacturonic acid, was used as a structural polymer. The concentrations of substances in the initial solutions were selected that were optimal for the synthesis of microcapsules. The main parameters for evaluating the resulting microparticles were the size of the capsules (less than 1 μm for oral inclusion), the zeta-potential, showing the tendency of the microparticles to stick together, and the completeness of the binding of the microparticles to chitosan. It was found that the optimal solutions for the synthesis of microparticles are: 15.7 ml of a solution of pectin 0.093% by weight, 3.3 ml of a solution of chitosan 0.07% by weight and 1.0 ml of a solution of CaCl2 20 mM. The diameter of the microparticles obtained by this method was 700-800 nm, and the value of their zetta-potential, equal to - (34 ± 3) mV, does not cross the particle adhesion threshold. It was also found that the synthesis of microparticles at these concentrations of calcium chloride provides the most complete binding of chitosan to their surface, which increases the mucoadhesive properties of microparticles."

scholarly journals Thermodynamic reassessment of the Mn-Ni-Si system

2015 ◽  
Vol 51 (2) ◽  
pp. 125-132 ◽  
Author(s):  
B. Hu ◽  
Y. Du ◽  
J.J. Yuan ◽  
Z.F. Liu ◽  
Q.P. Wang
Keyword(s):  
Experimental Data ◽  
Phase Diagram ◽  
Phase Diagrams ◽  
Thermodynamic Parameters ◽  
Ternary Phase ◽  
Sublattice Model ◽  
Diagram Approach ◽  
Measured Phase

Iased on the new experimental data available in the literature, the Mn-Ni-Si system has been reassessed using the CALPHAD (CALculation of PHAse Diagram) approach. Compared with the previous modeling, the ?8 and ?12 ternary phases were treated as the same phase according to the new experimental data. The Mn3Si phase was described with two sublattice model (Mn, Ni)3(Si)1. The reported new ternary phase ? was not considered in the present work. Comprehensive comparisons between the calculated and measured phase diagrams showed that a set of thermodynamic parameters of the Mn-Ni-Si system obtained in this work was more accurate than the previous one.

A phase diagram approach to study liquation cracking in alloy 718

1991 ◽  
Vol 22 (4) ◽  
pp. 887-902 ◽  
Author(s):  
B. Radhakrishnan ◽  
R. G. Thompson
Keyword(s):  
Phase Diagram ◽  
Alloy 718 ◽  
Liquation Cracking ◽  
Diagram Approach

Quantitative Prediction of Structure and Luminescent Properties of (Mg1-x-yBaxSry)1.95SiO4∶0.05Eu via Phase Diagram Approach

2019 ◽  
Vol 40 (12) ◽  
pp. 1494-1504
Author(s):  
汪 雨 WANG Yu ◽  
罗 岚 LUO Lan ◽  
郭 锐 GUO Rui ◽  
孙传耀 SUN Chuan-yao ◽  
高明远 GAO Ming-yuan
Keyword(s):  
Phase Diagram ◽  
Luminescent Properties ◽  
Quantitative Prediction ◽  
Diagram Approach

Weldability Approach to Duplex Stainless Steels Using Multicomponent Phase Diagrams

2005 ◽  
Vol 475-479 ◽  
pp. 2765-2768 ◽  
Author(s):  
Antonio J. Ramirez ◽  
Sérgio Duarte Brandi
Keyword(s):  
Phase Diagram ◽  
Phase Transformations ◽  
Phase Diagrams ◽  
Stainless Steels ◽  
Equilibrium Phase ◽  
Duplex Stainless Steels ◽  
Pseudobinary Phase Diagram ◽  
Equilibrium Process ◽  
Diagram Approach ◽  
Joint Microstructures

Welding is a non-equilibrium process. However, some weldability issues, as the extension of the heat-affected zone (HAZ) can be addressed using equilibrium phase diagrams. The 70 wt% Fe-Cr-Ni pseudo-binary phase diagram is commonly used to establish the phase transformations during welding of duplex stainless steels. The predicted results are assumed to be reasonably good for most of the duplex stainless steels. Thermodynamic calculations were used to determine multicomponent phase diagrams and volumetric fraction of phases present as a function of temperature several commercial duplex stainless steels. Results showed that simplified pseudobinary phase diagram approach is valid to estimate welded joint microstructures only for the low alloy duplex stainless steels as UNS S32304, but phase transformations and mainly solidification paths of high alloy duplex stainless steels should predicted only using a multi-component phase diagram.

scholarly journals The self assembly of proteins; probing patchy protein interactions

2015 ◽  
Vol 17 (7) ◽  
pp. 5413-5420 ◽  
Author(s):  
Susan James ◽  
Michelle K. Quinn ◽  
Jennifer J. McManus
Keyword(s):  
Phase Diagram ◽  
Thermodynamic Properties ◽  
Protein Interactions ◽  
Self Assembly ◽  
The Self ◽  
Protein Surface ◽  
Competing Interactions ◽  
Diagram Approach

Anisotropy is central to protein self-assembly. The kinetic and thermodynamic properties of proteins in which competing interactions exist due to the anisotropic or patchy nature of the protein surface have been explored using a phase diagram approach.

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