Chemical Forms of Mercury and Selenium in Fish Following Digestion with Simulated Gastric Fluid

2008 ◽  
Vol 21 (11) ◽  
pp. 2106-2110 ◽  
Author(s):  
Graham N. George ◽  
Satya P. Singh ◽  
Roger C. Prince ◽  
Ingrid J. Pickering
Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 449
Author(s):  
Ahmed M. Omer ◽  
Zyta M. Ziora ◽  
Tamer M. Tamer ◽  
Randa E. Khalifa ◽  
Mohamed A. Hassan ◽  
...  

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.


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 ◽  
...  

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 723
Author(s):  
He Xia ◽  
Ang Li ◽  
Jia Man ◽  
Jianyong Li ◽  
Jianfeng Li

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.


1994 ◽  
Vol 83 (11) ◽  
pp. 1543-1547 ◽  
Author(s):  
Tian Jian Yang ◽  
Quan Long Pu ◽  
Shen K. Yang

2012 ◽  
Vol 560-561 ◽  
pp. 434-437 ◽  
Author(s):  
Lan Wang ◽  
Wen Ji Guo ◽  
Yan Zhao Zhao

The objective of this paper was to prepare the composite of crefradine/montmorillionite in the method of solution intercalation. The drug load and intercalation rate varied with the drug concentration. X-ray diffraction (XRD), Fourier transformed infrared (FT-IR) Spectroscopy, and thermal analysis (TG-DSC) were applied to characterize composite mentioned above. Together with drug release tests, results indicate cefradine intercalated into montmorillionite.The release profiles of cefradine/MMT in simulated gastric fluid (pH 1.2) and simulated intestinal fluid (pH 7.4) at 37°Cduring 10h are shown in Fig. 4. The amount of cefradine in the beginning 2h came up to 35% and 50%, and in the following time, cefradine released slowly. The release behaviors met the requirements of sustained release.


2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Djaenudin ◽  
Endang Saepudin ◽  
Muhamad Nasir

 Chitosan-coated L. casei containing alginate capsules (shortened as L. casei capsules) were prepared by extruding L. casei containing alginate solution at different extrusion voltage and and flow rate followed by coating the wet capsules in chitosan solution. This study aimed to determine the effect of extrusion voltage and sodium alginate liquid flow rate on the viability of L. casei bacteria in the encapsulation process. The encapsulation process in this study was carried out by the extrusion method using sodium alginate of 1% (w/v) and chitosan of 0.2% (w/v). The resulted beads were immersed in a simulated gastric fluid (SGF) (NaCl 0.2%; HCl 0.5 M with a pH of 1.5) for 1, 60, and 120 min at 37 °C. The number of L. casei cells before encapsulation was 12.3 log CFU. After encapsulation, the maximum viability of L. Casei obtained by voltage variations of 0 kV and flow rate 5 mL/min were 12.26 log CFU.  After testing the beads in SGF for 1 min, the results obtained indicate that viability of L.casei in the sodium alginate - chitosan beads with an extrusion voltage of 0 kV and 5 mL/min was 11.8 log CFU/g. The result indicated that encapsulated L. casei in the sodium alginate - chitosan beads with a voltage of 0 kV and 5 mL/min was the highest survivability level of 97.38 %. The conclusions of the study were The higher extrusion voltage can kill more L. casei while the higher extrusion flow rate can protect more L. casei.


2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Djaenudin ◽  
Endang Saepudin ◽  
Muhamad Nasir

Alginate, nano chitin, and chitosan polymers can be used to protect the Lactobacillus casei  from gastric conditions. The goal of this study was to determine the effect of alginate, nano chitin, and chitosan as encapsulation materials of  L. casei  on their survivability in simulated gastric fluid (SGF). The encapsulation  process in this study was carried out by the extrusion  method. The resulted beads were soaked  in SGF (pH of 1.2 and 3) for 1 and 60  min at 37°C. In SGF pH 1.2 for 60 min, the survivability of L.casei in all variations of the experiment was 0% except those encapsulated from alginate (1%), nano chitin (0.2%), and chitosan (0.2) % of 75.35%. In SGF pH 3 for 60 min, the survivability of L.casei was 0% for beads unencapsulation and encapsulation made from alginate, while the highest survivability of L.casei was 81.22% obtained in various encapsulation experiments using alginate (1%), nano chitin (0.2%), and chitosan (0.2%). The addition of nano chitin or chitosan to L.casei encapsulation material can increase the survivability of L.casei, also showed that the combination of alginate, nano chitin, and chitosan  in the encapsulated material significantly increased the survivability of L.casei at SGF pH 1.2 and 3.


2011 ◽  
Vol 393-395 ◽  
pp. 119-122
Author(s):  
Dong Hua Wan ◽  
Fen Lin ◽  
Qu Xiang Liao

It’s well known that curcumin is practically insoluble in water. Therefore, to improve the drug dissolution rate, fusion approach was employed to prepare curcumin solid dispersions (SDs) in the carrier Pluronic F68 with three different drug loads. The dissolution rate of curcumin from the SDs was measured at simulated gastric fluid. The concentration of the dissolved drug in the medium was determined by HPLC. The dissolution rates of the formulations were dependent on the drug loading in SDs. 92.2% CUR was dissolved in 10 min from the SDs with 8.97% drug load, whereas the amounts of drug released were 65.8% and 84.2% within 120 min from the SDs with 18.9% and 29.0% drug loads, respectively. The Fourier transform infrared spectra indicated hydrogen bond between the drug and carrier. Furthermore, their physicochemical properties were well investigated using differential scanning calorimetry and X-ray diffraction. In the dispersions containing 8.97% CUR, the drug was in the molecular state. At a composition of approximately 18.9%, CUR was dispersed as micro-fine crystals. These interesting results indicate that the physical states of the drug in the carrier, which are governed by the drug loading, can affect the dissolution rate improvement.


Cosmetics ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 53 ◽  
Author(s):  
Joana Ramis ◽  
Catarina Coelho ◽  
Alba Córdoba ◽  
Paulo Quadros ◽  
Marta Monjo

Hydroxyapatite nanoparticles (HAP-NP) are incorporated in oral care products such as toothpastes and mouthwashes to treat dental sensitivity or to promote enamel remineralisation. Despite the good performance of HAP-NP in this application, it is important to ensure its safety for consumers. For that reason, the Scientific Committee on Consumer Safety (SCCS) evaluated the safety of HAP-NP as an oral care ingredient, but the issued opinion was not completely conclusive and the SCCS recommended that additional tests should be performed. Here, we used a commercially available human gingival epithelium (HGE) as a non-animal alternative and MTT cell viability, LDH activity, and IL-1alpha production were evaluated after 3.1% HAP-NP treatment for 10 min, 1 h, and 3 h. Moreover, the absorption of HAP-NP in the gingival tissue was assessed by transmission electron microscopy (TEM) analysis. Finally, the dissolution behaviour of HAP-NP in simulated gastric fluid was also investigated. No deleterious effect was observed for HGE tissues incubated with HAP-NP for all time-points and parameters evaluated. Moreover, a complete dissolution of 3.1% HAP-NP in simulated gastric fluid was observed after 7.5 min at 37 °C. In conclusion, our results evidence the safety of HAP-NP for oral care products with the use of an in vitro replacement alternative for human gingival epithelium and a simulated gastric fluid assay.


Sign in / Sign up

Export Citation Format

Share Document