Long-Term Release Kinetics of Colloidal Particles from Natural Porous Media

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

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Analysis of process of emulsions transport in hydrophilic/oleophilic granular porous media driven by capillary force

Technical Sciences ◽

10.31648/ts.2719 ◽

2018 ◽

Vol 2 (21) ◽

pp. 85-101

Author(s):

Olga Shtyka ◽

Łukasz Przybysz ◽

Mariola Błaszczyk ◽

Jerzy P. Sęk

Keyword(s):

Porous Media ◽

Experimental Research ◽

Granular Media ◽

Single Phase ◽

Influential Factor ◽

Dispersed Phase ◽

Porous Structures ◽

Phase Concentration ◽

Granular Porous Media ◽

Kinetics Of

The research focuses on the issues concerning a process of multiphase liquids transport in granular porous media driven by the capillary pressure. The current publication is meant to introduce the results of experimental research conducted to evaluate the kinetics of the imbibition and emulsions behavior inside the porous structures. Moreover, the influence of the dispersed phase concentration and granular media structure on the mentioned process was considered. The medium imbibition with emulsifier-stabilized emulsions composed of oil as the dispersed phase in concentrations of 10 vol%, 30 vol%, and 50 vol%, was investigated. The porous media consisted of oleophilic/hydrophilic beads with a fraction of 200–300 and 600–800 μm. The experimental results provided that the emulsions imbibition in such media depended stronger on its structure compare to single-phase liquids. The increase of the dispersed phase concentration caused an insignificant mass decreasing of the imbibed emulsions and height of its penetration in a sorptive medium. The concentrations of the imbibed dispersions exceeded their initial values, but reduced with permeants front raise in the granular structures that can be defined as the influential factor for wicking process kinetics.

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Analysis of K+ release kinetics of biomass ash with different pH

CHINESE JOURNAL OF ECO-AGRICULTURE ◽

10.3724/sp.j.1011.2014.30916 ◽

2014 ◽

Vol 22 (2) ◽

pp. 171-176

Author(s):

Kan WANG ◽

Zifang WANG ◽

Ming GAO ◽

Yaohua HUANG ◽

Xiaofei HAN ◽

...

Keyword(s):

Release Kinetics ◽

Biomass Ash ◽

Kinetics Of ◽

K Release

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Design and release kinetics of liposomes containing abiraterone acetate for treatment of prostate cancer

Sensors International ◽

10.1016/j.sintl.2020.100077 ◽

2021 ◽

Vol 2 ◽

pp. 100077

Author(s):

Sudipta Das ◽

Arnab Samanta ◽

Shouvik Mondal ◽

Debatri Roy ◽

Amit Kumar Nayak

Keyword(s):

Prostate Cancer ◽

Release Kinetics ◽

Abiraterone Acetate ◽

Kinetics Of

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Risk Assessment of Agricultural Plastic Films Based on Release Kinetics of Phthalate Acid Esters

Environmental Science & Technology ◽

10.1021/acs.est.0c07008 ◽

2021 ◽

Vol 55 (6) ◽

pp. 3676-3685

Author(s):

Yu Wang ◽

Fang Wang ◽

Leilei Xiang ◽

Chenggang Gu ◽

Marc Redmile-Gordon ◽

...

Keyword(s):

Risk Assessment ◽

Release Kinetics ◽

Plastic Films ◽

Kinetics Of ◽

Acid Esters ◽

Phthalate Acid Esters

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Dual release kinetics of antimalarials from soy protein isolate-carbopol-polyacrylamide based hydrogels

Journal of Applied Polymer Science ◽

10.1002/app.43918 ◽

2016 ◽

Vol 133 (37) ◽

Cited By ~ 9

Author(s):

Blessing Atim Aderibigbe ◽

Zandile Mhlwatika

Keyword(s):

Soy Protein ◽

Release Kinetics ◽

Soy Protein Isolate ◽

Protein Isolate ◽

Dual Release ◽

Kinetics Of

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Halloysite nanotubes filled with salicylic acid and sodium diclofenac: effects of vacuum pumping on loading and release properties

Journal of Nanostructure in Chemistry ◽

10.1007/s40097-021-00391-z ◽

2021 ◽

Author(s):

Lorenzo Lisuzzo ◽

Giuseppe Cavallaro ◽

Stefana Milioto ◽

Giuseppe Lazzara

Keyword(s):

Salicylic Acid ◽

Release Kinetics ◽

Halloysite Nanotubes ◽

Drug Molecules ◽

Sodium Diclofenac ◽

Tunable Release ◽

Feature Based ◽

Kinetics Of ◽

Filling Mechanism

AbstractIn this work, we investigated the effects of the vacuum pumping on both the loading efficiencies and the release kinetics of halloysite nanotubes filled with drug molecules dissolved in ethanol. As model drugs, salicylic acid and sodium diclofenac were selected. For comparison, the loading of the drug molecules was conducted on platy kaolinite to explore the key role of the hollow tubular morphology on the filling mechanism of halloysite. The effects of the pressure conditions used in the loading protocol were interpreted and discussed on the basis of the thermodynamic results provided by Knudsen thermogravimetry, which demonstrated the ethanol confinement inside the halloysite cavity. Several techniques (TEM, FTIR spectroscopy, DLS and $$\zeta$$ ζ -potential experiments) were employed to characterize the drug filled nanoclays. Besides, release kinetics of the drugs were studied and interpreted according to the loading mechanism. This work represents a further step for the development of nanotubular carriers with tunable release feature based on the loading protocol and drug localization into the carrier. Graphic abstract The filling efficiency of halloysite nanotubes is enhanced by the reduction of the pressure conditions used in the loading protocol.

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