pH-Sensitive Polymer Blends Used as Coating Materials to Control Drug Release from Spherical Beads: Elucidation of the Underlying Mass Transport Mechanisms

2005 ◽  
Vol 22 (7) ◽  
pp. 1129-1141 ◽  
Author(s):  
Florence Lecomte ◽  
Juergen Siepmann ◽  
Mathias Walther ◽  
Ross J. MacRae ◽  
Roland Bodmeier
Keyword(s):  
Drug Release ◽  
Mass Transport ◽  
Polymer Blends ◽  
Ph Sensitive ◽  
Transport Mechanisms ◽  
Coating Materials ◽  
Control Drug ◽  
Ph Sensitive Polymer ◽  
Mass Transport Mechanisms ◽  
Control Drug Release

pH-Sensitive Polymer Blends used as Coating Materials to Control Drug Release from Spherical Beads:  Importance of the Type of Core

2005 ◽  
Vol 6 (4) ◽  
pp. 2074-2083 ◽  
Author(s):  
Florence Lecomte ◽  
Juergen Siepmann ◽  
Mathias Walther ◽  
Ross J. MacRae ◽  
Roland Bodmeier
Keyword(s):  
Drug Release ◽  
Polymer Blends ◽  
Ph Sensitive ◽  
Coating Materials ◽  
Control Drug ◽  
Ph Sensitive Polymer ◽  
Control Drug Release

Aqueous HPMCAS coatings: Effects of formulation and processing parameters on drug release and mass transport mechanisms

2006 ◽  
Vol 63 (3) ◽  
pp. 262-269 ◽  
Author(s):  
Florence Siepmann ◽  
Juergen Siepmann ◽  
Mathias Walther ◽  
Ross MacRae ◽  
Roland Bodmeier
Keyword(s):  
Drug Release ◽  
Mass Transport ◽  
Processing Parameters ◽  
Transport Mechanisms ◽  
Mass Transport Mechanisms

Drug release from lipid-based implants: Elucidation of the underlying mass transport mechanisms

2006 ◽  
Vol 314 (2) ◽  
pp. 137-144 ◽  
Author(s):  
C. Guse ◽  
S. Koennings ◽  
F. Kreye ◽  
F. Siepmann ◽  
A. Goepferich ◽  
...  
Keyword(s):  
Drug Release ◽  
Mass Transport ◽  
Transport Mechanisms ◽  
Mass Transport Mechanisms

Control drug release behavior by highly stable and pH sensitive poly(N-vinylpyrrolidone)-block-poly(4-vinylpyridine) copolymer micelles

Polymer ◽  
2021 ◽  
Vol 213 ◽  
pp. 123329
Author(s):  
Avnish Kumar Mishra ◽  
Junsub Lim ◽  
Jaeyong Lee ◽  
Soyeong Park ◽  
Yeseong Seo ◽  
...  
Keyword(s):  
Drug Release ◽  
Ph Sensitive ◽  
Release Behavior ◽  
Control Drug ◽  
Drug Release Behavior ◽  
Copolymer Micelles ◽  
Control Drug Release

Microencapsulation and Nanoencapsulation: A Review

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
V. Suganya ◽  
V. Anuradha
Keyword(s):  
Drug Release ◽  
New Technology ◽  
Inert Material ◽  
Food Industries ◽  
Control Drug ◽  
Advantages And Disadvantages ◽  
Nano Scale ◽  
Pharmaceutical Industries ◽  
The Difference ◽  
Control Drug Release

Encapsulation is a process of enclosing the substances within an inert material which protects from environment as well as control drug release. Recently, two type of encapsulation has been performed in several research. Nanoencapsulation is the coating of various substances within another material at sizes on the nano scale. Microencapsulation is similar to nanoencapsulation aside from it involving larger particles and having been done for a greater period of time than nanoencapsulation. Encapsulation is a new technology that has wide applications in pharmaceutical industries, agrochemical, food industries and cosmetics. In this review, the difference between micro and nano encapsulation has been explained. This article gives an overview of different methods and reason for encapsulation. The advantages and disadvantages of micro and nano encapsulation technology were also clearly mentioned in this paper.

Cassava starch bionanocomposites for control drug release

2018 ◽  
Vol 2 (5) ◽  
pp. 20-26
Author(s):  
Debi Prasanna Mohanty ◽  
Keyword(s):  
Drug Release ◽  
Cassava Starch ◽  
Control Drug ◽  
Control Drug Release

scholarly journals Temperature Effects on the Crystallization and Coarsening of Nano-CeO2 Powders

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
H. F. Lopez ◽  
H. Mendoza
Keyword(s):  
Activation Energy ◽  
Mass Transport ◽  
Ostwald Ripening ◽  
Effect Of Temperature ◽  
Transport Mechanisms ◽  
X Ray Diffraction ◽  
Measured Activation Energy ◽  
Measured Activation ◽  
Mass Transport Mechanisms ◽  
Nanoparticle Sizes

The effect of temperature on nano-CeO2 particle coarsening is investigated. The nanoceria powders were synthesized using the microemulsion method and then exposed to temperatures in the range of 373–1273 K. It was found that the nanoparticles exhibited a strong tendency to form agglomerates and through the application of ultrasound these agglomerates could be broken into smaller sizes. In addition average nanoparticle sizes were determined by powder X-ray diffraction (XRD). The outcome of this work indicates that the initial nano-CeO2 powders are amorphous in nature. Annealing promotes CeO2 crystallization and a slight shift in the (111) XRD intensity peaks corresponding to CeO2. Moreover, at temperatures below 773 K, grain growth in nano-CeO2 particles is rather slow. Apparently, mass transport through diffusional processes is not likely to occur as indicated by an estimated activation energy of 20 kJ/mol. At temperatures above 873 K, the measured activation energy shifted to 105 kJ/mol suggesting a possible transition to Ostwald-Ripening type mass transport mechanisms.

scholarly journals The ABCG2 multidrug transporter is a pump gated by a valve and an extracellular lid

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Narakorn Khunweeraphong ◽  
Daniel Szöllősi ◽  
Thomas Stockner ◽  
Karl Kuchler
Keyword(s):  
Drug Release ◽  
Molecular Mechanism ◽  
Salt Bridge ◽  
Multidrug Transporter ◽  
Peristaltic Pump ◽  
Disulfide Bridges ◽  
Control Drug ◽  
Atp Binding Cassette Transporter ◽  
Extracellular Loops ◽  
Control Drug Release

AbstractThe human ATP-binding cassette transporter ABCG2 is a key to anticancer resistance and physiological detoxification. However, the molecular mechanism of substrate transport remains enigmatic. A hydrophobic di-leucine motif in the ABCG2 core separates a large intracellular cavity from a smaller upper cavity. We show that the di-leucine motif acts as a valve that controls drug extrusion. Moreover, the extracellular structure engages the re-entry helix and all extracellular loops to form a roof architecture on top of the upper cavity. Disulfide bridges and a salt bridge limit roof flexibility, but provide a lid-like function to control drug release. We propose that drug translocation from the central to the upper cavities through the valve is driven by a squeezing motion, suggesting that ABCG2 operates similar to a peristaltic pump. Finally, the roof contains essential residues, offering therapeutic options to block ABCG2 by either targeting the valve or essential residues in the roof.

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