scholarly journals Rapid Kinetics of Size and pH-Dependent Dissolution and Aggregation of Silver Nanoparticles in Simulated Gastric Fluid

2015 ◽  
Vol 119 (35) ◽  
pp. 20632-20641 ◽  
Author(s):  
Jessica L. Axson ◽  
Diana I. Stark ◽  
Amy L. Bondy ◽  
Sonja S. Capracotta ◽  
Andrew D. Maynard ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Ph Dependent ◽  
Rapid Kinetics ◽  
Kinetics Of

scholarly journals Dexamethasone-Loaded Chitosan Beads Coated with a pH-Dependent Interpolymer Complex for Colon-Specific Drug Delivery

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Jomarien García-Couce ◽  
Nancy Bada-Rivero ◽  
Orestes D. López Hernández ◽  
Antonio Nogueira ◽  
Pablo C. Caracciolo ◽  
...  
Keyword(s):  
Gastric Fluid ◽  
Vinyl Pyrrolidone ◽  
Simulated Gastric Fluid ◽  
Interpolymer Complex ◽  
Simulated Intestinal Fluid ◽  
Chitosan Beads ◽  
Oil Emulsion ◽  
Ph Dependent ◽  
Poly Vinyl Pyrrolidone ◽  
A Site

Chitosan (CS) microparticles loaded with dexamethasone were prepared by spray drying, followed by coating with a pH-dependent interpolymer complex based on poly(acrylic acid)/poly(vinyl pyrrolidone) using an water-in-oil emulsion technique. The aim of this research was to evaluate the influence of PAA/PVP coating on the release of dexamethasone from loaded chitosan microparticles, in simulated gastric fluid (SGF, pH=1.2) and simulated intestinal fluid (SIF, pH=6.8). The release of dexamethasone from uncoated loaded CS microparticles was similar in both fluids, and almost complete release of the drug was achieved in 5 hours. In the coated loaded CS microparticles, the release of dexamethasone in SGF was reduced considerably, very close to zero, due to the interpolymer complex formation at low pH, demonstrating that this system applied as pH-dependent coating has a potential as a site-specific delivery system.

scholarly journals Protein corona-induced modification of silver nanoparticle aggregation in simulated gastric fluid

2016 ◽  
Vol 3 (6) ◽  
pp. 1510-1520 ◽  
Author(s):  
Andrew P. Ault ◽  
Diana I. Stark ◽  
Jessica L. Axson ◽  
Justin N. Keeney ◽  
Andrew D. Maynard ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
Protein Corona ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Nanoparticle Aggregation

This works shows enhanced aggregation of silver nanoparticles in simulated gastric fluid when pepsin protein is present.

scholarly journals In Vitro Study of Adsorption Kinetics of Dextromethorphan Syrup onto Activated Charcoal in Simulated Gastric and Intestinal Fluids

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Shobha Regmi ◽  
Balmukunda Regmi ◽  
Sajan Lal Shyaula ◽  
Shiva Pathak ◽  
Bishnu Prasad Bhattarai ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Activated Charcoal ◽  
In Vitro Study ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Simulated Intestinal Fluid ◽  
Intestinal Fluids ◽  
Vitro Model ◽  
Kinetics Of

Adsorption kinetics of dextromethorphan (DXM) syrup in simulated gastric and intestinal fluids onto activated charcoal (AC) were investigated in an in vitro model. The adsorption studies were performed as a function of time, initial concentration, and temperature. The quantification of DXM adsorbed onto AC was obtained from the Langmuir adsorption isotherms using HPLC. The maximum adsorption capacities (at 95% confidence limits) of AC for DXM were 111.615 [106.38; 126.85] mg in simulated intestinal environment (pH 6.8) and 78.314 [86.206; 70.422] mg in simulated gastric environment (pH 1.2). The adsorption capacity of AC for DXM in simulated gastric fluid (pH 1.2) was not significantly different from the adoption capacity of AC for DXM in simulated intestinal fluid (pH 6.8). Moreover, the adsorption kinetics behavior of dextromethorphan onto AC followed pseudo-second-order kinetics. Our results show that AC in therapeutically acceptable doses can be beneficial in the majority of oral overdose of DXM.

Pepsin-induced modification of silver nanoparticles in simulated gastric fluid

2021 ◽  
Vol 44 ◽  
pp. 100491
Author(s):  
Tae Hyeon Jeong ◽  
Kyung Bin Kim ◽  
Su Yeon Kim ◽  
Yu Ra Kim ◽  
Jong Hoon Kim ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid

Iodoacetate inactivation of rape alcohol dehydrogenase

1980 ◽  
Vol 45 (5) ◽  
pp. 1601-1607 ◽  
Author(s):  
Marie Stiborová ◽  
Sylva Leblová
Keyword(s):  
Alcohol Dehydrogenase ◽  
Protein Molecule ◽  
Sulfhydryl Groups ◽  
Inactivation Rate ◽  
First Order ◽  
Ph Dependent ◽  
Kinetics Of

Iodoacetate inactivates rape alcohol dehydrogenase (ADH, EC 1.1.1.1). The inactivation rate follows the kinetics of the first order, is pH-dependent, and decreases below pH 7.5. Besides irreversible alkylation of the sulfhydryl groups of the enzyme iodoacetate also forms a reversible complex with rape ADH. The coenzyme (NAD) and its analogs (ATP, ADP, AMP) competitively protect the enzyme against alkylation; o-phenanthroline also protects the enzyme against alkylation yet noncompetitively with respect to iodoacetate. Imidazole and o-phenanthroline compete with one another for binding to the protein molecule of rape ADH. Whereas o-phenanthroline decreases the inactivation rate imidazole increases the rate of iodoacetate inactivation.

scholarly journals Formulation of Quaternized Aminated Chitosan Nanoparticles for Efficient Encapsulation and Slow Release of Curcumin

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 449
Author(s):  
Ahmed M. Omer ◽  
Zyta M. Ziora ◽  
Tamer M. Tamer ◽  
Randa E. Khalifa ◽  
Mohamed A. Hassan ◽  
...  
Keyword(s):  
Slow Release ◽  
Sodium Tripolyphosphate ◽  
Chitosan Nanoparticles ◽  
Gastric Fluid ◽  
Release Profile ◽  
Simulated Gastric Fluid ◽  
Maximum Value ◽  
Structure Surface ◽  
Drug Encapsulation Efficiency

An effective drug nanocarrier was developed on the basis of a quaternized aminated chitosan (Q-AmCs) derivative for the efficient encapsulation and slow release of the curcumin (Cur)-drug. A simple ionic gelation method was conducted to formulate Q-AmCs nanoparticles (NPs), using different ratios of sodium tripolyphosphate (TPP) as an ionic crosslinker. Various characterization tools were employed to investigate the structure, surface morphology, and thermal properties of the formulated nanoparticles. The formulated Q-AmCs NPs displayed a smaller particle size of 162 ± 9.10 nm, and higher surface positive charges, with a maximum potential of +48.3 mV, compared to native aminated chitosan (AmCs) NPs (231 ± 7.14 nm, +32.8 mV). The Cur-drug encapsulation efficiency was greatly improved and reached a maximum value of 94.4 ± 0.91%, compared to 75.0 ± 1.13% for AmCs NPs. Moreover, the in vitro Cur-release profile was investigated under the conditions of simulated gastric fluid [SGF; pH 1.2] and simulated colon fluid [SCF; pH 7.4]. For Q-AmCs NPs, the Cur-release rate was meaningfully decreased, and recorded a cumulative release value of 54.0% at pH 7.4, compared to 73.0% for AmCs NPs. The formulated nanoparticles exhibited acceptable biocompatibility and biodegradability. These findings emphasize that Q-AmCs NPs have an outstanding potential for the delivery and slow release of anticancer drugs.

Effect of CTABr (surfactant) on the kinetics of formation of silver nanoparticles by Amla extract

2021 ◽  
Vol 329 ◽  
pp. 115537
Author(s):  
Nazia Iqbal ◽  
S.M. Shakeel Iqubal ◽  
Aejaz Abdullatif Khan ◽  
Tasneem Mohammed ◽  
Ali Mohamed Alshabi ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Kinetics Of Formation ◽  
Kinetics Of

Modelling inactivation of wild‐type and clinical Escherichia coli O26 strains using UV‐C and thermal treatment and subsequent persistence in simulated gastric fluid

2019 ◽  
Vol 127 (5) ◽  
pp. 1564-1575 ◽  
Author(s):  
V.S. Castro ◽  
D.K.A. Rosario ◽  
Y.S. Mutz ◽  
A.C.C. Paletta ◽  
E.E.S. Figueiredo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Thermal Treatment ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Wild Type ◽  
Uv C

scholarly journals Fabrication of Multi-Layered Microspheres Based on Phase Separation for Drug Delivery

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 723
Author(s):  
He Xia ◽  
Ang Li ◽  
Jia Man ◽  
Jianyong Li ◽  
Jianfeng Li
Keyword(s):  
Aqueous Solution ◽  
Phase Separation ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Sustained Drug Release ◽  
Simulated Intestinal Fluid ◽  
Glycol Diacrylate ◽  
Emulsion Droplets ◽  
Collection Tube ◽  
Poly Ethylene

In this work, we used a co-flow microfluidic device with an injection and a collection tube to generate droplets with different layers due to phase separation. The phase separation system consisted of poly(ethylene glycol) diacrylate 700 (PEGDA 700), PEGDA 250, and sodium alginate aqueous solution. When the mixture droplets formed in the outer phase, PEGDA 700 in the droplets would transfer into the outer aqueous solution, while PEGDA 250 still stayed in the initial droplet, breaking the miscibility equilibrium of the mixture and triggering the phase separation. As the phase separation proceeded, new cores emerged in the droplets, gradually forming the second and third layers. Emulsion droplets with different layers were polymerized under ultraviolet (UV) irradiation at different stages of phase separation to obtain microspheres. Microspheres with different layers showed various release behaviors in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). The release rate decreased with the increase in the number of layers, which showed a potential application in sustained drug release.

scholarly journals Rapid kinetics of myo-inositol trisphosphate binding and dissociation in cerebellar microsomes.

1994 ◽  
Vol 269 (47) ◽  
pp. 29642-29649
Author(s):  
Z Hannaert-Merah ◽  
J F Coquil ◽  
L Combettes ◽  
M Claret ◽  
J P Mauger ◽  
...  
Keyword(s):  
Inositol Trisphosphate ◽  
Rapid Kinetics ◽  
Kinetics Of
Sign in / Sign up

Export Citation Format

Share Document