Adsorbed Tween 80 is unique in its ability to improve the stability of gold nanoparticles in solutions of biomolecules

Nanoscale ◽  
2010 ◽  
Vol 2 (10) ◽  
pp. 2114 ◽  
Author(s):  
Yuyun Zhao ◽  
Zhuo Wang ◽  
Wei Zhang ◽  
Xingyu Jiang
Keyword(s):  
Gold Nanoparticles ◽  
Tween 80 ◽  
The Stability

scholarly journals Effects of pH and Electrolytes on Castor Oil Emulsions with Various Stabilisers Using Khaya senegalensis Gum as an Emulsifier

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Deryl Nii Okantey Kuevi ◽  
Noble Kuntworbe ◽  
Enoch Ayertey
Keyword(s):  
Castor Oil ◽  
Xanthan Gum ◽  
Hydroxypropyl Methylcellulose ◽  
Physical Stability ◽  
Tween 80 ◽  
Volume Data ◽  
Emulsifying Property ◽  
Khaya Senegalensis ◽  
Effects Of Ph ◽  
The Stability

Dispersed systems such as emulsions are easily destabilised during processing and storage since they are thermodynamically unstable systems. It is for this reason emulsifiers/stabilisers are frequently employed in pharmaceutical emulsion formulations to increase their short- and long-term kinetic stability. This current study seeks to investigate the potential emulsifying property of gums obtained from Khaya senegalensis (family: Meliaceae) trees. Gums were collected, authenticated, oven-dried, milled, filtered, and purified using 96% ethanol. The microbial quality of the gum was assessed following the BP (2013) specifications. The purified gum was free from some selected pathogenic microorganisms, rendering the gum safe for consumption. The emulsifying property was investigated by formulating emulsions using castor oil and employing the dry gum method. The ratios of oil-to-water-to-gum for the formulation of a stable emulsion were determined. The stability of the emulsion was evaluated, and an effort was made to improve the stability by incorporating Tween 80, hydroxypropyl methylcellulose, and xanthan gum. From the results, it can be inferred that Tween 80 (0.5%) was able to stabilise the emulsion. Addition of xanthan gum worsened the creaming. The effects of pH (4.0, 5.5, 7.2, 9.0, and 11.0) and electrolytes (0.1 M of NaCl, KCl, and CaCl2) on the physical stability of oil-in-water emulsions were studied during 12 weeks of storage. Percentage creaming volume and whether there was phase inversion were the criteria used as the evaluation parameter. From the percentage creaming volume data, emulsions formulated with both gums showed the lowest creaming volumes at pH of 7.2, followed by the acidic regions (pH 4.0, 5.5), with the basic regions (pH 9.0, 11.0) recording the highest creaming volumes. The effects of the various electrolytes at a constant concentration of 0.1 M on the o/w emulsions were found in this order NaCl < KCl < CaCl2. This study proves that Khaya senegalensis gum can successfully be employed as an emulsifying agent in pharmaceutical formulations.

scholarly journals Surface Adsorption of the Alpha-Emitter Astatine-211 to Gold Nanoparticles Is Stable In Vivo and Potentially Useful in Radionuclide Therapy

2021 ◽  
Vol 2 (4) ◽  
pp. 196-207
Author(s):  
Emanuel Sporer ◽  
Christian B. M. Poulie ◽  
Sture Lindegren ◽  
Emma Aneheim ◽  
Holger Jensen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Surface Adsorption ◽  
Radiochemical Yield ◽  
Gold Surface ◽  
Mouse Serum ◽  
Control Group ◽  
Alpha Emitter ◽  
Before And After ◽  
The Stability

Targeted α-therapy (TAT) can eradicate tumor metastases while limiting overall toxicity. One of the most promising α-particle emitters is astatine-211 (211At). However, 211At-carbon bonds are notoriously unstable in vivo and no chelators are available. This hampers its adoption in TAT. In this study, the stability of 211At on the surface of gold nanoparticles (AuNPs) was investigated. The employed AuNPs had sizes in the 25–50 nm range. Radiolabeling by non-specific surface-adsorption in >99% radiochemical yield was achieved by mixing 211At and AuNPs both before and after polyethylene glycol (PEG) coating. The resulting 211At-AuNPs were first challenged by harsh oxidation with sodium hypochlorite, removing roughly 50% of the attached 211At. Second, incubation in mouse serum followed by a customized stability test, showed a stability of >95% after 4 h in serum. This high stability was further confirmed in an in vivo study, with comparison to a control group of free 211At. The AuNP-associated 211At showed low uptake in stomach and thyroid, which are hallmark organs of uptake of free 211At, combined with long circulation and high liver and spleen uptake, consistent with nanoparticle biodistribution. These results support that gold surface-adsorbed 211At has high biological stability and is a potentially useful delivery system in TAT.

Stability of carbon monoxide oxidation process on gold nanoparticles

2020 ◽  
Vol 8 (1) ◽  
pp. 116-124
Author(s):  
P. P. Kostrobij ◽  
◽  
I. A. Ryzha ◽  
Keyword(s):  
Carbon Monoxide ◽  
Gold Nanoparticles ◽  
Reaction Mechanisms ◽  
Structural Changes ◽  
Oxidation Process ◽  
Lyapunov Method ◽  
Catalyst Surface ◽  
Carbon Monoxide Oxidation ◽  
One Step ◽  
The Stability

The stability conditions for mathematical models of carbon monoxide oxidation on the surface of gold nanoparticles are investigated. The cases of reaction mechanisms of one-step and step-by-step transformation of reagents are consecutively considered. Using the stability analysis by Lyapunov method, it is shown that models which take into account the possibility of structural changes of the catalyst surface can predict the occurrence of oscillatory mode in the system as a result of Hopf instability.

Evaluation of the phase solubility of inclusion complexes of diisopropylphenol (INN) with hydroxypropyl-β-cyclodextrin

2021 ◽  
pp. 27-32
Author(s):  
Olga Mikhailovna Balakhonova ◽  
Viktoriya Sergeevna Tyukova ◽  
Stanislav Anatolievich Kedik
Keyword(s):  
Aqueous Solution ◽  
Inclusion Complex ◽  
Inclusion Complexes ◽  
Tween 80 ◽  
Phase Solubility ◽  
Cyclodextrin Inclusion ◽  
Solubility Method ◽  
Cyclodextrin Inclusion Complex ◽  
The Stability ◽  
Solubility Profiles

The paper presents the results of a study of the stability of aqueous solutions of inclusion complexes of hydroxypropyl-β-cyclodextrin with diisopropylphenol in various systems by the Higuchi-Connors phase solubility method. The phase solubility profiles for each system corresponding to the AN type are determined graphically, and the stability constants of the resulting inclusion complexes are calculated. An aqueous solution containing 0.2 % Tween 80 and 0.2 % mannitol was selected as the optimal condition for obtaining the hydroxypropyl-β-cyclodextrin inclusion complex with diisopropylphenol.

scholarly journals SYNTHESIS AND STABILITY OF RESVERATROL-CONJUGATED GOLD NANOPARTICLES MODIFIED WITH POLYETHYLENE GLYCOL

2020 ◽  
pp. 230-236
Author(s):  
RADITYA ISWANDANA ◽  
RICHA NURSELVIANA ◽  
SUTRIYO SUTRIYO
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Zeta Potential ◽  
High Performance ◽  
Entrapment Efficiency ◽  
Test Results ◽  
Novel Method ◽  
The Stability ◽  
Phosphate Buffered Saline

Objective: Gold nanoparticles (AuNPs) are highly useful for drug delivery, but their application is limited by their stability as they readily aggregate.This issue can be prevented by adding a stabilizing agent such as resveratrol (RSV), which is a polyphenol derived from plants, that is used to preventcancer. Therefore, we propose a novel method to prepare stable RSV-conjugated nanoparticles modified with polyethylene glycol (RSV-AuNP-PEG).Methods: In the first step, the Turkevich method was used to synthesize the AuNPs. Then, PEG was added as stabilizer agent and conjugated with RSV.The synthesized conjugates were characterized using ultraviolet-visible spectrophotometry, Fourier transform infrared spectroscopy, particle sizeanalysis, and high-performance liquid chromatography.Results: The obtained RSV-AuNP-PEG had a particle size of 83.93 nm with a polydispersity index (PDI) of 0.562 and formed a translucent purple-redfluid in solution. The zeta potential was −22.9 mV, and the highest entrapment efficiency was 75.86±0.66%. For comparison, the RSV-AuNP solutionwas purple and turbid, the particle size was 51.97 nm with a PDI of 0.694, and the zeta potential was −24.6 mV. The stability test results showed thatthe storage stability of RSV-AuNP-PEG was better than that of AuNP-RSV. Further, the RSV-AuNP-PEG was shown to be most stable in 2% bovine serumalbumin (BSA) while the AuNP-RSV was most stable in 2% BSA in phosphate-buffered saline pH 7.4.Conclusion: These results show that modification of RSV-conjugated AuNPs with PEG effectively prevents their aggregation in storage, but only incertain mediums.

scholarly journals Uji Stabilitas Sediaan Mikroemulsi Menggunakan Hidrolisat Pati (DE 35–40) Sebagai Stabilizer

2006 ◽  
Vol 3 (1) ◽  
pp. 8-21
Author(s):  
Mahdi Jufri ◽  
◽  
Effionora Anwar ◽  
Putri Margaining Utami
Keyword(s):  
Drug Delivery ◽  
Dosage Form ◽  
Tween 80 ◽  
Microemulsion System ◽  
Hydrophobic Drug ◽  
Dextrose Equivalent ◽  
Oil In Water ◽  
External Phase ◽  
The Stability ◽  
Made In

Various solubilization techniques have been developed to enhance the bioavailability of hydrophobic drugs. One of the solubilization techniques is preparation of microemulsion. Microemulsion is a potential carrier in drug delivery system because it has many advantageous characteristics. In this research, hydrophobic drug was made in a dosage form of oil in water (O/W) microemulsion using ketoprofen as a model and investigated the influence of adding starch hydrolisates with dextrose equivalent (DE) 35-40 in variety concentrations (0,0%; 1,5%; 2,0%; 2,5%) to the stability of this microemulsion system. This microemulsion consisted of isopropyl miritate as oil phase, tween 80 and lechitin as surfactants, ethanol as cosurfactant, propylene glycol as cosolvent, starch hydrolisates DE 35–40 as stabilizer, and water as external phase. The evaluation was stability test both phisically and chemically. The result showed that the stability of microemulsion system increased significantly by adding starch hydrolisates DE 35-40 at 2,5%.

scholarly journals PREPARATION, CHARACTERIZATION AND ANTIOXIDANT ACTIVITY OF XANTHONE-LOADED MAKING (HODGSONIA HETEROCLITA) MICROEMULSIONS

2017 ◽  
Vol 9 (3) ◽  
pp. 262
Author(s):  
Sunee Chansakaow ◽  
Panee Sirisa-ard ◽  
Ruttiros Khonkarn
Keyword(s):  
Antioxidant Activity ◽  
Propylene Glycol ◽  
Droplet Size ◽  
Tween 80 ◽  
Screw Press ◽  
Pharmaceutical Applications ◽  
Microemulsion Based Gel ◽  
Release Study ◽  
The Stability

Objective: The aim of this study was to incorporate xanthone into Making (Hodgsonia heteroclita) microemulsions and to evaluate the antioxidant activity of the formulations.Methods: Making oil was obtained from the seed of Hodgsonia heteroclite by a screw press machine. The solubility of xanthone in various oils, surfactants, and co-surfactants was investigated. Stable Making microemulsion and microemulsion-based gel were simultaneously loaded with xanthone. Finally, an in vitro xanthone release study was carried out and antioxidant activity was determined.Results: The optimal formulations of the Making microemulsion consisted of Making oil, capryol 90, tween 80, propylene glycol, and water. The average droplet size of xanthone-loaded Making microemulsion was around 110–130 nm. It was found that the stability of the xanthone-loaded Making microemulsion-based gel was higher than the xanthone-loaded Making microemulsion. Besides, the release of xanthone from the Making microemulsion-based gel was lower than that of the Making microemulsion. Moreover, it was found that the antioxidant activity of both xanthone-loaded Making microemulsion (TEAC and EC values of 9.8 mmol/mg and 14.8 mmol/mg, respectively) and microemulsion-based gel (TEAC and EC values of 9.4 mmol/mg and 18.5 mmol/mg, respectively) remained high even after extended storage conditions.Conclusion: It was concluded that Making oil is an attractive material to deliver xanthone in pharmaceutical applications.

Novel Bionic Biomembrane Supported by Gold Nanoparticles/Cellulose Hybrid Films

2012 ◽  
Vol 84 ◽  
pp. 13-18 ◽  
Author(s):  
Zhi Ming Liu ◽  
Yuan Lin An ◽  
Wen Jian Wu
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Solutions ◽  
Lipid Membranes ◽  
Hybrid Film ◽  
Bilayer Lipid Membranes ◽  
Hybrid Films ◽  
Bilayer Lipid ◽  
Long Period ◽  
Highly Active ◽  
The Stability

As one of the main methods to study biomembranes, the construction of highly active bionic biomembrane systems is very important. Based on the hybrid film of gold nanoparticles and cellulose, a novel system of bionic biomembrane is demonstrated. The ratio effects of lecithin to cholesterin on the stability of bilayer lipid membranes are studied. Lipid solutions that can form stable membranes in the air and in some aqueous solutions are prepared. The bionic biomembranes composed of bilayer lipid membranes and hybrid films of gold nanoparticles and cellulose can be sustained for a long period in aqueous solutions. The bionic biomembranes also exhibit some interesting electrochemical properties.

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