Gelation behavior, drug solubilization capacity and release kinetics of poloxamer 407 aqueous solutions: The combined effect of copolymer, cosolvent and hydrophobic drug

2020 ◽  
Vol 303 ◽  
pp. 112639 ◽  
Author(s):  
Ljiljana Djekic ◽  
Bojan Čalija ◽  
Đorđe Medarević
2017 ◽  
Vol 240 ◽  
pp. 622-629 ◽  
Author(s):  
Wannisa Boonlai ◽  
Vimon Tantishaiyakul ◽  
Namon Hirun ◽  
Suppalak Phaisan ◽  
Thitima Uma

2014 ◽  
Vol 22 (2) ◽  
pp. 171-176
Author(s):  
Kan WANG ◽  
Zifang WANG ◽  
Ming GAO ◽  
Yaohua HUANG ◽  
Xiaofei HAN ◽  
...  

1981 ◽  
Vol 46 (3) ◽  
pp. 693-700 ◽  
Author(s):  
Milan Strašák ◽  
Jaroslav Majer

The kinetics of oxidation of alkenes by thallic sulphate in aqueous solutions, involving the two reaction steps-the hydroxythallation and the dethallation - was studied, and the effect of salts on the kinetics was examined; this made it possible to specify more precisely the reaction mechanism and to suggest a qualitative model of the reaction coordinate. It was found that in homogeneous as well as in heterogeneous reaction conditions, the reaction can be accelerated appreciably by adding tetraalkylammonium salts. These salts not only operate as catalysts of the phase transfer, but also exert a significant kinetic effect, which can be explained with a simplification in terms of a stabilization of the transition state of the reaction.


1995 ◽  
Vol 60 (4) ◽  
pp. 568-575
Author(s):  
Karel Sporka ◽  
Jiří Hanika ◽  
Vladimír Jůn

Preparation of skeletal Co-Mo catalysts by controlled impregnation of aluminosilicate skeletons containing deposited gamma-alumina with aqueous solutions of active component precursors has been investigated. The activity of the laboratory catalysts in gas oil hydrodesulfurization has been determined. Kinetics of impregnation of skeletal supports, the effect of their type, and the dependence of catalyst activity on the content of cobalt and molybdenum sulfides are reported. HDS skeletal catalysts prepared were compared with the extruded types. It was found that skeletal HDS catalysts show the higher activity (related to the content of alumina and Co-Mo sulfides) than the extruded ones due to the less significant effect of internal diffusion. However, if the activity is related to the same volume of catalyst bed, the activity of skeletal catalysts is only one fourth of that of the extruded types.


1990 ◽  
Vol 55 (2) ◽  
pp. 345-353 ◽  
Author(s):  
Ivan Halaša ◽  
Milica Miadoková

The authors investigated periodic potential changes measured on oriented sections of Al single crystals during spontaneous dissolution in dilute aqueous solutions of KOH, with the aim to find optimum conditions for the formation of potential oscillations. It was found that this phenomenon is related with the kinetics of the reaction investigated, whose rate also changed periodically. The mechanism of the oscillations is discussed in view of the experimental findings.


2021 ◽  
Vol 2 ◽  
pp. 100077
Author(s):  
Sudipta Das ◽  
Arnab Samanta ◽  
Shouvik Mondal ◽  
Debatri Roy ◽  
Amit Kumar Nayak

2021 ◽  
Vol 55 (6) ◽  
pp. 3676-3685
Author(s):  
Yu Wang ◽  
Fang Wang ◽  
Leilei Xiang ◽  
Chenggang Gu ◽  
Marc Redmile-Gordon ◽  
...  

Author(s):  
Lorenzo Lisuzzo ◽  
Giuseppe Cavallaro ◽  
Stefana Milioto ◽  
Giuseppe Lazzara

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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