scholarly journals Potential application of surfactant systems in formulation of dosage forms with slightly soluble substances

2012 ◽  
Vol 66 (5) ◽  
pp. 667-676
Author(s):  
Mladen Milovic ◽  
Jelena Djuris ◽  
Dragana Vasiljevic ◽  
Zorica Djuric ◽  
Svetlana Ibric
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Castor Oil ◽  
High Specific Surface Area ◽  
Homogeneous Distribution ◽  
Dissolution Profile ◽  
Commercial Products ◽  
Hydrogenated Castor Oil ◽  
Surfactant Systems

In order to achieve fast release of ibuprofen, slightly soluble model substance (0.52104 mol/l), surfactant systems for oral use with different PEG-40 hydrogenated castor oil (C)/diethylene glycol monoethyl ether (T) ratios were investigated. Comparison between dissolution profiles for ibuprofen from formulated systems and from two commercial products, film tablets and soft capsules, is presented in this paper. Photon correlation spectroscopy has shown that after high dilution with water, surfactant systems were able to form micellar solutions. The size of micelles varies from 14.8 ? 0,075 nm to 16.2 ? 0,021 nm with increasing C/T ratio from 1:2 to 2:1. Although with increasing content of PEG-40 hydrogenated castor oil larger micelles have formed, lower values of polydispersity index indicated that more homogeneous distribution of micelles size was gained. Conductometric analysis has demonstrated that system composing of C/T ratio 2:1, has shown most pronounced interaction between droplets, which can be seen as high rise of electrical conductivity with increasing water content (% (wwater/wtotal)) in the sample. No significant difference in percolation threshold between formulations with different C/T ratios was observed. Different surfactant systems were adsorbed on magnesium aluminometasilicate, as adsorbent with high specific active surface (?300 m2/g), in order to investigate potential influence of adsorbent on ibuprofen dissolution rate. Formulated systems, with or without adsorbent were filled in hard gelatin capsules. The dissolution profiles of ibuprofen from different formulations were obtained in 30 minutes by dissolution apparatus with rotating baskets and compared with dissolution profiles of ibuprofen from commercial products. For formulations without adsorbent faster release of ibuprofen in first minutes of dissolution test, showed formulations with C/T ratio 2:1 and 1:1. Magnesium aluminometasilicate, as adsorbent with high specific surface area, significantly improved release rate of ibuprofen from formulation with C/T ratio 2:1, but, for formulation with C/T ratio 1:1, significantly lower release of ibuprofen was observed. Formulations with other C/T ratios in terms of fast ibuprofen release did not give satisfying results. Obtained results show that in comparison to dissolution profile of ibuprofen from commercial products proper C/T ratio as well as magnesium aluminometasilicate, as adsorbent with high specific surface area, can significantly increase release of ibuprofen.

scholarly journals Nanoporous Quasi-High-Entropy Alloy Microspheres

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
Author(s):  
Lianzan Yang ◽  
Yongyan Li ◽  
Zhifeng Wang ◽  
Weimin Zhao ◽  
Chunling Qin
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Hierarchical Porous

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.

KCl-assisted activation: Moringa oleifera branch-derived porous carbon for high performance supercapacitor

2021 ◽  
Vol 45 (12) ◽  
pp. 5712-5719
Author(s):  
Yongxiang Zhang ◽  
Peifeng Yu ◽  
Mingtao Zheng ◽  
Yong Xiao ◽  
Hang Hu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
High Performance ◽  
Moringa Oleifera ◽  
High Specific Surface Area ◽  
Porous Carbons

Porous carbons with a high specific surface area (2314–3470 m2 g−1) are prepared via a novel KCl-assisted activation strategy for high-performance supercapacitor.

Carbon material with high specific surface area and high pseudocapacitance: Possible application in supercapacitors

2021 ◽  
Vol 319 ◽  
pp. 111063
Author(s):  
Yury M. Volfkovich ◽  
Valentin E. Sosenkin ◽  
Alexei Y. Rychagov ◽  
Alexandr V. Melezhik ◽  
Alexei G. Tkachev ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Material ◽  
High Specific Surface Area

Efficient conversion of CO2 to methane using thin-layer SiOx matrix anchored nickel catalysts

2019 ◽  
Vol 43 (33) ◽  
pp. 13217-13224 ◽  
Author(s):  
Xieyi Huang ◽  
Peng Wang ◽  
Zhichao Zhang ◽  
Shaoning Zhang ◽  
Xianlong Du ◽  
...  
Keyword(s):  
Thin Layer ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Geometric Structure ◽  
Nickel Catalysts ◽  
High Specific Surface Area ◽  
Efficient Conversion

Thin-layer SiOx matrix anchored nickel catalysts with high specific surface area and a unique electronic/geometric structure were fabricated for efficient CO2 methanation.

High specific surface area LaFeCo perovskites—Synthesis by nanocasting and catalytic behavior in the reduction of NO with CO

2009 ◽  
Vol 90 (3-4) ◽  
pp. 441-450 ◽  
Author(s):  
R.K.C. de Lima ◽  
M.S. Batista ◽  
M. Wallau ◽  
E.A. Sanches ◽  
Y.P. Mascarenhas ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Catalytic Behavior ◽  
Reduction Of No
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