Chitosan–Magnesium Aluminum Silicate Nanocomposite Coatings

2016 ◽  
pp. 101-124
Author(s):  
Thaned Pongjanyakul
Keyword(s):  
Nanocomposite Coatings ◽  
Aluminum Silicate ◽  
Magnesium Aluminum Silicate

Novel chitosan−magnesium aluminum silicate nanocomposite film coatings for modified-release tablets

2011 ◽  
Vol 407 (1-2) ◽  
pp. 132-141 ◽  
Author(s):  
Wanwisa Khunawattanakul ◽  
Satit Puttipipatkhachorn ◽  
Thomas Rades ◽  
Thaned Pongjanyakul
Keyword(s):  
Nanocomposite Film ◽  
Aluminum Silicate ◽  
Modified Release ◽  
Film Coatings ◽  
Magnesium Aluminum Silicate

scholarly journals Enhanced foam-stabilizing performance by the addition of clays: A comparison of magnesium aluminum silicate with sodium bentonite

2020 ◽  
Vol 189 ◽  
pp. 105558
Author(s):  
Tengda Wang ◽  
Lili Yang ◽  
Guancheng Jiang ◽  
Paul F. Luckham ◽  
Xiao Yang
Keyword(s):  
Aluminum Silicate ◽  
Sodium Bentonite ◽  
Magnesium Aluminum Silicate

scholarly journals Reaction products of Sm2Zr2O7 with calcium-magnesium-aluminum-silicate (CMAS) and their evolution

2021 ◽  
Author(s):  
Yinghua Wang ◽  
Zhuang Ma ◽  
Ling Liu ◽  
Yanbo Liu
Keyword(s):  
Solid Solution ◽  
Aluminum Silicate ◽  
Thermal Barrier ◽  
Reaction Products ◽  
Barrier Coatings ◽  
Magnesium Aluminum Silicate ◽  
Composition Segregation ◽  
Calcium Magnesium ◽  
New Generation ◽  
Sand Dust

AbstractDuring flight, many silicates (sand, dust, debris, fly ash, etc.) are ingested by an engine. They melt at high operating temperatures on the surface of thermal barrier coatings (TBCs) to form calcium-magnesium-aluminum-silicate (CMAS) amorphous settling. CMAS corrodes TBCs and causes many problems, such as composition segregation, degradation, cracking, and disbanding. As a new generation of TBC candidate materials, rare-earth zirconates (such as Sm2Zr2O7) have good CMAS resistance properties. The reaction products of Sm2Zr2O7 and CMAS and their subsequent changes were studied by the reaction of Sm2Zr2O7 and excess CMAS at 1350 °C. After 1 h of reaction, Sm2Zr2O7 powders were not completely corroded. The reaction products were Sm-apatite and c-ZrO2 solid solution. After 4 h of reaction, all Sm2Zr2O7 powders were completely corroded. After 24 h of reaction, Sm-apatite disappeared, and the c-ZrO2 solid solution remained.

Reduced Tetracycline Bioavailability Caused by Magnesium Aluminum Silicate in Liquid Formulations of Bismuth Subsalicylate

1997 ◽  
Vol 31 (12) ◽  
pp. 1460-1464 ◽  
Author(s):  
Daniel P Healy ◽  
Richard J Dansereau ◽  
Alisha B Dunn ◽  
Chris E Clendening ◽  
Anthony W Mounts ◽  
...  
Keyword(s):  
Tap Water ◽  
Linear Regression Analysis ◽  
Active Agent ◽  
Tetracycline Hydrochloride ◽  
Aluminum Silicate ◽  
Liquid Formulation ◽  
Maximum Serum ◽  
Bismuth Subsalicylate ◽  
Magnesium Aluminum Silicate

RATIONALE: Bismuth subsalicylate, tetracycline hydrochloride, and metronidazole are widely used in combination for the treatment of Helicobacter pylori infections. As a result, there is renewed interest in the interaction between tetracycline and bismuth subsalicylate. OBJECTIVE: To determine whether the observed decrease in tetracycline bioavailability is due to the active drug bismuth subsalicylate via complexation, or to magnesium aluminum silicate (Veegum), an inactive excipient present only in the liquid formulation of bismuth subsalicylate, which might adsorb the tetracycline, rendering it unavailable for systemic absorption. METHODS: Eleven healthy volunteers participated in a randomized three-period, three-treatment complete crossover study with a 7-day washout interval between treatments. After an overnight fast, subjects received a 500-mg capsule of tetracycline hydrochloride with either tap water, 30 mL of bismuth subsalicylate (525 mg) liquid containing Veegum (Pepto-Bismol), or 30 mL of a specially formulated bismuth subsalicylate (525 mg) liquid without Veegum. Blood was collected for 24 hours after each dose of tetracycline. Serum was assayed for tetracycline concentration by HPLC. In addition, standard in vitro ultraviolet spectrophotometric methods were used to determine the capacity for complexation of bismuth with tetracycline and for adsorption of tetracycline to Veegum. RESULTS: Compared with the reference treatment of tetracycline hydrochloride with water, the liquid formulation of bismuth subsalicylate containing Veegum decreased the maximum serum concentration (Cmax) of tetracycline by 21% and the serum tetracycline AUC by 27% (p < 0.001). The bismuth subsalicylate formulation without Veegum resulted in decreases in Cmax and AUC of 11% and 13%, respectively (p > 0.05 vs. tetracycline hydrochloride with water). Multiple linear regression analysis of the spectral absorbance data demonstrated a calculated recovery of tetracycline of 100.9% and, therefore, a lack of in vitro complexation with bismuth. At pH 1.2, the amount of tetracycline adsorbed to Veegum ranged from 91.5% to 97.2% over the concentration range of 0.25 to 2 mg/mL. At pH 7.0, the values ranged from 82.9% to 83.9% over the concentration range of 0.25 to 1 mg/mL. CONCLUSIONS: In vitro and in vivo data from this study indicate that Veegum, a suspending agent, and not the active agent bismuth subsalicylate, is the primary ingredient in liquid formulations of bismuth subsalicylate responsible for a decrease in tetracycline bioavailability. In addition, the mechanism of interaction is not likely due to complexation between tetracycline and bismuth subsalicylate, as previously postulated, but rather is caused by adsorption of tetracycline to the excipient Veegum, which is present only in the liquid formulation of bismuth subsalicylate. The clinical relevance of this interaction has not been determined.

Characterization of chitosan–magnesium aluminum silicate nanocomposite films for buccal delivery of nicotine

2013 ◽  
Vol 55 ◽  
pp. 24-31 ◽  
Author(s):  
Thaned Pongjanyakul ◽  
Wanwisa Khunawattanakul ◽  
Clare J. Strachan ◽  
Keith C. Gordon ◽  
Satit Puttipipatkhachorn ◽  
...  
Keyword(s):  
Nanocomposite Films ◽  
Aluminum Silicate ◽  
Buccal Delivery ◽  
Magnesium Aluminum Silicate

scholarly journals Investigations on the mechanism, kinetics and isotherms of ammonium and humic acid co-adsorption at low temperature by 4A-molecular sieves modified from attapulgite

RSC Advances ◽  
2017 ◽  
Vol 7 (28) ◽  
pp. 17095-17106 ◽  
Author(s):  
Nan Sun ◽  
Wenxin Shi ◽  
Lixin Ma ◽  
Shuili Yu
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Humic Acid ◽  
Low Temperature ◽  
Molecular Sieves ◽  
Co Adsorption ◽  
Aluminum Silicate ◽  
Silicate Mineral ◽  
Magnesium Aluminum Silicate ◽  
Kinetics And Isotherms

Attapulgite (ATP) is a type of natural magnesium aluminum silicate mineral and has been applied as an adsorbent to remove organic pollutants and heavy metals in aqueous solution.

scholarly journals Deterioration and Microstructural Evolution of the Fly Ash Geopolymer Concrete against MgSO4Solution

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Tao Long ◽  
Qingyuan Wang ◽  
Zhongwei Guan ◽  
Yu Chen ◽  
Xiaoshuang Shi
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Magnesium Sulfate ◽  
Strength Loss ◽  
Sulfate Attack ◽  
Aluminum Silicate ◽  
Geopolymer Concrete ◽  
Portland Cement Concrete ◽  
Sodium Aluminum Silicate ◽  
Magnesium Aluminum Silicate

Fly ash geopolymer concrete (FAGC) and ordinary Portland cement concrete (OPCC) specimens were immersed in 5% MgSO4solution undergoing 32 wetting-drying and heating-cooling cycles. Their compressive behavior was investigated after every 8 cycles. Several microstructure analysis techniques were applied on the samples to identify the materials formed due to magnesium sulfate attack, including XRD, FTIR, SEM, and EDS. Experimental results elucidated that the compressive strength loss ratio in the heating group of FAGC was 12.7%, while that of OPCC was 17.8%, which means that FAGC had better magnesium sulfate resistance than OPCC. The compressive strength loss of OPCC was due to the formation of gypsum under the magnesium sulfate attack exposed to wetting-drying and heating-cooling cycles. The deterioration mechanisms of FAGC against MgSO4solution were discovered to be that sodium aluminum silicate hydrate (N-A-S-H) gels reacted with MgSO4, leading to the creation of low strength magnesium aluminum silicate hydrate (M-A-S-H) gels.

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