The Use of Xanthan Gum in An Ophthalmic Liquid Dosage Form: Rheological Characterization of the Interaction With Mucin

2002 ◽  
Vol 91 (4) ◽  
pp. 1117-1127 ◽  
Author(s):  
Jens Ceulemans ◽  
Inge Vinckier ◽  
Annick Ludwig
2020 ◽  
Vol 30 (1) ◽  
pp. 27-38
Author(s):  
Mingyang Tan ◽  
Yating Mao ◽  
Travis W. Walker

AbstractThis investigation proposes a synthetic biofluid, artificial sputum medium (ASM) and xanthan gum (XG), that mimics the mucus from a patient with cystic fibrosis, and investigates the rheological properties both macroscopically and microscopically. Macroscopic rheological characterization cannot address the heterogeneity or the behavior of particle transport inside the mucus. Microscopic rheology enables the characterization of the microenvironment by using microparticles as probes.The addition of XG to ASM provides a tunable parameter that enables the mechanical properties to be consistent with real mucus. Particles that were suspended in a media of ASM with XG displayed a subdiffusive behavior at short timescales with a diffusive exponent that decreases with an increase in concentration of XG. At long timescales, particles that were suspended in ASM+XG with a concentration of XG of 0.1% to 0.4% displayed diffusive behavior. While in more concentrated samples (0.5% and 1.0%), the particles were constrained inside local elastic “cages”. The microscopic moduli that were calculated showed consistently lower moduli than rotational rheometry. This discrepancy suggests that the solutions of XG have a hierarchical structure that better represents the weakly associated microstructure of mucus that is found in real sputum.


TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 641-649
Author(s):  
JOSHUA OMAMBALA ◽  
CARL MCINTYRE

The vast majority of tissue production uses creping to achieve the required set of properties on the base sheet. The Yankee coating helps to develop the desired crepe that in turn determines properties such as bulk and softness. The adhesion of the sheet to the Yankee surface is a very important characteristic to consider in achieving the desired crepe. The coating mix usually consists of the adhesive, modifier, and release. A good combination of these components is essential to achieving the desired properties of the tissue or towel, which often are determined by trials on the machine that can be time consuming and lead to costly rejects. In this paper, five compositions of an industrial Yankee coating adhesive, modifier, and release were examined rheologically. The weight ratio of the adhesive was kept constant at 30% in all five compositions and the modifier and release ratios were varied. The normal force and work done by the different compositions have been shown at various temperatures simulating that of the Yankee surface, and the oscillatory test was carried out to explain the linear and nonlinear viscoelastic characteristic of the optimal coating composition.


Author(s):  
Luiz Eduardo Rodrigues Vieira ◽  
Leonardo Rosa Ribeiro da Silva ◽  
Felipe Chagas Rodrigues de Souza ◽  
Wisley Sales ◽  
Álisson Rocha Machado

Author(s):  
Joel López Bonilla ◽  
Cesar Celis ◽  
Danmer Maza

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