Effect of montmorillonite on the swelling behavior and drug‐release behavior of nanocomposite hydrogels

Lee, Wen‐Fu; Fu, Yu

doi:10.1002/app.12624

Cited by 177 publications

(121 citation statements)

References 29 publications

Supporting

Mentioning

115

Contrasting

Unclassified

Order By: Relevance

“…Algumas empresas comercializam esmectitas de grau farmacêutico como, por exemplo, as argilas Veegum ® e a Polargel ® , que passam por um processo de lavagem em água. 44 Embora muitos trabalhos relatem a preparação de híbridos a partir de argilas organofílicas 45 ou a partir de nanocompósitos polímero-argila, 46 nos ateremos aqui ao caso específico da intercalação direta dos fármacos nas argilas. Nesse caso, as moléculas de interesse são imobilizadas entre as lamelas por um processo de troca catiônica.…”

Section: Fármacosunclassified

Modificação química de argilas: desafios científicos e tecnológicos para obtenção de novos produtos com maior valor agregado

Teixeira‐Neto¹,

Teixeira-Neto²

2009

Quím. Nova

View full text Add to dashboard Cite

Section: Fármacosunclassified

Modificação química de argilas: desafios científicos e tecnológicos para obtenção de novos produtos com maior valor agregado

Teixeira‐Neto¹,

Teixeira-Neto²

2009

Quím. Nova

View full text Add to dashboard Cite

“…The relative movement of the boundary was extracted via image processing of a large series of images taken during polymerization. If these data are plotted double logarithmically as suggested by Lee et al, 29 when they measured swelling kinetics of PNIPAAM-Montmorillonite gels, the slope of the regression line through the data points would give the exponent n in the heuristic equation (3) n t…”

Section: Swelling Kineticsmentioning

confidence: 99%

Oxygen-Controlled Phase Segregation in Poly(N-isopropylacrylamide)/Laponite Nanocomposite Hydrogels

et al. 2012

View full text Add to dashboard Cite

The combination of nanoparticles and polymers into nanocomposite gels has been shown to be a promising route to create soft materials with new or improved properties. In the present work we have made use of Laponite nanoparticles in combination with a poly(N-isopropylacrylamide) (PNIPAAM) polymer, and describe a phenomenon taking place during polymerization and gelling of this system. The presence of small amounts of oxygen in the process induce two distinctly separated phases, one polymer rich and one polymer deficient water-clay phase. Complex interactions between clay, oxygen and the polymer are found to govern the behavior of these phases. It is also observed that the initial clay concentration can be used to directly control the volume fraction of the polymer-deficient phase. The dynamics of the phase boundary is found to be dependent on water penetration, and in general to present 2 a non-Fickian behavior. An approach using video recording for monitoring hydrogel swelling is also presented and its advantages addressed.

show abstract

“…The application of such nanocomposites is diverse, ranging from coating 9 to pharmaceutical drug delivery systems. 10,11 Several studies have investigated the effect of intercalation of ionic surfactants on the flow behavior of montmorillonite clays. The large surface area of the platelet faces, and their negative charge, may favor the aggregation of cationic surfactant molecules as hemimicelles and micelles.…”

Section: Abend and Lagalymentioning

confidence: 99%

Effect of selected non-ionic surfactants on the flow behavior of aqueous veegum suspensions

Kennedy

2007

AAPS PharmSciTech

View full text Add to dashboard Cite

The aim of this work was to investigate the influence of some non-ionic surfactants, Tween 80 and Brij 98, on the viscosity and flow behavior of a commercial montmorillonite clay, Veegum Granules. The effect of different concentrations of the surfactants on the shear stress-shear rate rheograms of hydrated concentrated clay suspensions was determined by shear viscometry. The addition of either surfactant increased the plastic viscosity and the yield stress of the suspensions. Furthermore, both surfactants altered the thixotropy of the suspensions to an extent that depended on both the surfactant concentration and the time of equilibration of the surfactant and Veegum. Brij 98 had a greater and more rapid effect. It is proposed that the surfactant polar head-groups anchor at the tetrahedral sheet surface, leaving the alkyl chains extending away from the edges and faces. Consequently, the alkyl chains undergo hydrophobic interactions that facilitate the association between the platelets and increase the physical structure within the suspension. Stereochemical differences between the polar groups may lead to differences in the way the surfactants associate with the tetrahedral sheet and hence their ultimate effect on the rheological behavior. There is a significant interaction between these surfactants and montmorillonite clays, and the rheological changes that occur could have a major impact on any pharmaceutical formulation that uses these ingredients.

show abstract

Effect of montmorillonite on the swelling behavior and drug‐release behavior of nanocomposite hydrogels

Cited by 177 publications

References 29 publications

Modificação química de argilas: desafios científicos e tecnológicos para obtenção de novos produtos com maior valor agregado

Modificação química de argilas: desafios científicos e tecnológicos para obtenção de novos produtos com maior valor agregado

Oxygen-Controlled Phase Segregation in Poly(N-isopropylacrylamide)/Laponite Nanocomposite Hydrogels

Effect of selected non-ionic surfactants on the flow behavior of aqueous veegum suspensions

Contact Info

Product

Resources

About