scholarly journals Influence of Internal Structure of the Sorbents on Diazepam Sorption from Simulated Intestinal Fluid

2021 ◽  
Vol 11 (3) ◽  
pp. 1158
Author(s):  
Mircea Stefan ◽  
Ioana Stefan ◽  
Ioana-Alexandra Negoita ◽  
Viorel Ordeanu ◽  
Daniela Simina Stefan
Keyword(s):  
Internal Structure ◽  
Activated Charcoal ◽  
Good Description ◽  
Zero Point ◽  
Sorption Process ◽  
Intestinal Fluid ◽  
Simulated Intestinal Fluid ◽  
Zero Point Of Charge ◽  
Langmuir Isotherm Model ◽  
Positively Charged

The capacity of natural Na-montmorillonite and activated charcoal for sorption of diazepam from simulated intestinal fluid (SIF) was studied. The main characteristics of the sorbents were determined. In order to characterize the sorption process of diazepam the influence of the pH, contact time and ethanol presence in SIF was analyzed. Adsorption isotherms for the diazepam-activated charcoal and diazepam-natural Na-montmorillonite systems were determined. The Langmuir isotherm model provided a very good description of diazepam sorption. Furthermore, the pH-drift method was used to determine the specific pH at zero point of charge (pHzpc) of the sorbents. The obtained results show that the internal structure of the sorbents and pH of the SIF solutions are very important for diazepam sorption. Both the surface of the activated charcoal and natural Na-montmorillonite are positively charged below the pHzpc so the sorption of diazepam is higher below this point and occur by van der Waals forces. The presence of ethanol in simulated intestinal fluid lowers the adsorption of diazepam on both sorbents.

THE ZERO POINT OF CHARGE OF OXIDES1

1962 ◽  
Vol 66 (6) ◽  
pp. 967-973 ◽  
Author(s):  
G. A. Parks ◽  
P. L. de Bruyn
Keyword(s):  
Zero Point ◽  
Zero Point Of Charge

Development and Validation of UV-Visible Spectrophotometric method for the Estimation of Curcumin and Tetrahydrocurcumin in Simulated Intestinal Fluid

2021 ◽  
pp. 2971-2975
Author(s):  
Jai Bharti Sharma ◽  
Sherry Sherry ◽  
Shailendra Bhatt ◽  
Vipin Saini ◽  
Manish Kumar
Keyword(s):  
Drug Release ◽  
Spectrophotometric Method ◽  
Tween 80 ◽  
Solvent System ◽  
Intestinal Fluid ◽  
Simulated Intestinal Fluid ◽  
Validation Parameters ◽  
Administration Method ◽  
Uv Visible ◽  
Development And Validation

Background: Due to solubility issues of curcumin and tetrahydrocurcumin, there is a need for the development of a UV-Visible spectrophotometric method that can estimate the drug release precisely and accurately. The addition of surfactant in the dissolution medium in low concentration achieved bio-comparable surface activity and can be used to estimate the drug release from formulations by avoiding sink conditions. Objective: The purpose of the present investigation was to develop a simple and précise UV-Visible spectrophotometric method for the determination of curcumin and tetrahydrocurcumin after oral administration. Method: A UV-Visible spectrophotometric method was developed using an appropriate solvent system for the estimation of curcumin and tetrahydrocurcumin. The solvent system having simulated intestinal fluid and particular concentration of surfactant was selected and further validated according to guidelines of the international conference on harmonization (ICH), the analytical parameter like linearity, precision and accuracy, etc. were studied. Results: Simulated intestinal fluid pH 7.4 with tween 80 at 1 % concentration satisfied all the conditions relative to peak quality at the stated wavelength for curcumin and intestinal fluid pH 7.4 with tween 80 at 0.5% concentration satisfied all the conditions relative to Peak quality at the stated wavelength for tetrahydrocurcumin. The developed methods were found within the range of all the validation parameters. Conclusion: The proposed method was found to be very simple and precise and can be used for routine quantitative analysis of curcumin and tetrahydrocurcumin.

Short note: Infliximab recovery in a simulated intestinal fluid of the upper intestine tract

2019 ◽  
Vol 27 (4) ◽  
pp. 241-246 ◽  
Author(s):  
Donatella Volpatti ◽  
Eleonora Gulisano ◽  
Mauro Spanghero
Keyword(s):  
Short Note ◽  
Intestinal Fluid ◽  
Simulated Intestinal Fluid

Bovine Serum Albumin Nanoparticle Promotes the Stability of Quercetin in Simulated Intestinal Fluid

2011 ◽  
Vol 59 (11) ◽  
pp. 6292-6298 ◽  
Author(s):  
Ru Fang ◽  
Ruifang Hao ◽  
Xia Wu ◽  
Qi Li ◽  
Xiaojing Leng ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Intestinal Fluid ◽  
Simulated Intestinal Fluid ◽  
The Stability

Lead(II) Adsorption by Raw and Acid-Activated Vermiculite

2012 ◽  
Vol 557-559 ◽  
pp. 1127-1130 ◽  
Author(s):  
Wen Jun Xiang
Keyword(s):  
Specific Surface ◽  
Surface Charge ◽  
Langmuir Isotherm ◽  
Cation Exchange Capacity ◽  
Zero Point ◽  
Exchange Capacity ◽  
Zero Point Of Charge ◽  
Adsorption Capacities ◽  
Adsorption Data ◽  
Hcl Solution

Acid-activated vermiculite (AAV) was prepared by treating raw vermiculite (RV) at 80°C with HCl solution. The surface properties and Pb(II) adsorption characteristics of RV and AAV were studied. The specific surface area (SSA), cation exchange capacity (CEC), pH at zero point of charge (pHZPC), and surface charge at pH 5.8 of AAV were 287.62 m2/g, 24.85 cmol/kg, pH 3.06, and -0.361 mmol/g, respectively. Compared to RV, the SSA, CEC and surface charge of AAV increased, but the value of pHZPC decreased. At pH 5.8, the maximum adsorption capacities (qmax) for Pb(II) of RV and AAV were 10.72 and 18.53 mg/g, respectively. The adsorption data for Pb(II) by RV and AAV could be well fitted using Langmuir isotherm (R2 =0.990 and 0.995, respectively)

1. The fly in the cathedral

2015 ◽  
Author(s):  
Frank Close
Keyword(s):  
Internal Structure ◽  
Nuclear Physics ◽  
Positive Charge ◽  
X Rays ◽  
Ernest Rutherford ◽  
Nuclear Atom ◽  
Positively Charged

‘The fly in the cathedral’ charts the discovery of the nuclear atom and the start of modern atomic and nuclear physics. It began in 1895 with the discovery of X-rays by Wilhelm Roentgen and radioactivity by Henri Becquerel. In 1897, J.J. Thomson discovered the electron and realised they were common to all atoms, which implied that atoms have an internal structure. Negatively-charged electrons are bound to positively-charged entities within the atom, but what carries this positive charge and how is it distributed? It was Ernest Rutherford, in 1911, who announced his solution: all of an atom’s positive charge and most of its mass are contained in a compact nucleus at the centre.

scholarly journals New crosstalk between probiotics Lactobacillus plantarum and Bacillus subtilis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tao Yu ◽  
Jian Kong ◽  
Li Zhang ◽  
Xinyi Gu ◽  
Mingyu Wang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Bacillus Subtilis ◽  
Lactobacillus Plantarum ◽  
Bile Salts ◽  
Intestinal Tract ◽  
Molecular Mechanisms ◽  
Oxygen Species ◽  
Intestinal Fluid ◽  
Simulated Intestinal Fluid

Abstract It was reported that oral administration of Bacillus favored the growth of Lactobacillus in the intestinal tract. Here, this phenomenon was confirmed by co-cultivation of Bacillus subtilis 168 and Lactobacillus plantarum SDMCC050204-pL157 in vitro. To explain the possible molecular mechanisms, B. subtilis 168 cells were incubated in simulated intestinal fluid at 37 °C for 24 h, and up to 90% of cells autolysed in the presence of bile salts. Addition of the autolysate to medium inoculated with Lb. plantarum SDMCC050204 decreased the concentration of H2O2 in the culture, alleviated DNA damage and increased the survival of Lb. plantarum, as like the results of exogenous heme addition. These results suggested that the autolysate provided heme, which activated the heme-dependent catalase KatA in Lb. plantarum SDMCC050204. HPLC confirmed the presence of heme in the autolysate. Disruption of the Lb. plantarum SDMCC050204 katA gene abolished the protective effect of the B. subtilis 168 autolysate against H2O2 stress. We thus hypothesized that the beneficial effect of Bacillus toward Lactobacillus was established through activation of the heme-dependent catalase and remission of the damage of reactive oxygen species against Lactobacillus. This study raised new crosstalk between the two frequently-used probiotics, highlighting heme-dependent catalase as the key mediator.

scholarly journals Colloid Formation by Drugs in Simulated Intestinal Fluid

2010 ◽  
Vol 53 (10) ◽  
pp. 4259-4265 ◽  
Author(s):  
Allison K. Doak ◽  
Holger Wille ◽  
Stanley B. Prusiner ◽  
Brian K. Shoichet
Keyword(s):  
Intestinal Fluid ◽  
Simulated Intestinal Fluid ◽  
Colloid Formation
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