Effect of solvent pre-treatment on the structures and dissolution of microcrystalline cellulose in lithium chloride/dimethylacetamide

Cellulose ◽  
2019 ◽  
Vol 26 (5) ◽  
pp. 3095-3109 ◽  
Author(s):  
Weiku Wang ◽  
Yinhui Li ◽  
Weijie Li ◽  
Baohua Zhang ◽  
Yaodong Liu
2021 ◽  
Vol 11 (11) ◽  
pp. 1465
Author(s):  
Weifeng Peng ◽  
Yijun Shen ◽  
Qiang Wang ◽  
Jing Ding ◽  
Xin Wang

Epileptogenesis may be responsible for both of recurrent seizures and comorbid depression in epilepsy. Disease-modifying treatments targeting the latent period before spontaneous recurrent seizures may contribute to the remission of seizures and comorbid depression. We hypothesized that pre-treatment with 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU), a soluble epoxide hydrolase (sEH) inhibitor, which has anti-inflammatory and neuroprotective effects might rescue status epilepticus (SE)-induced dendritic spine loss and alleviate depressive behaviours. Rats were either pre-treated with TPPU (0.1 mg/kg/d) intragastrically or with vehicle (40% polyethylene glycol 400) from 7 days before to 7 days after SE that was induced with lithium chloride and pilocarpine intraperitoneally. Rats in the Control group were given saline instead. The forced swim test (FST) was performed on the 8th day after SE to evaluate the depression-like behaviours in rats. The results showed that seizures severity during SE was significantly decreased, and the immobility time during FST was significantly increased through TPPU pre-treatment. Moreover, pre-treatment with TPPU attenuated inflammations including microglial gliosis and the level of proinflammatory cytokine IL-1β in the hippocampus; in addition, neuronal and dendritic spine loss in the subfields of hippocampus was selectively rescued, and the expression of NR1 subunit of N-methyl-D-aspartate (NMDA) receptor, ERK1/2, CREB, and their phosphorylated forms involved in the dendritic spine development were all significantly increased. We concluded that pre-treatment with TPPU attenuated seizures severity during SE and depressive behaviours during the period of epileptogenesis probably by rescuing dendritic spine loss in the hippocampus.


2018 ◽  
Vol 3 (1) ◽  
pp. 87-96
Author(s):  
Muhammad Arif Fahmi Supian ◽  
Khairatun Najwa Mohd Amin ◽  
Saidatul Shima Jamari ◽  
Shahril Mohamad

In this study, microcrystalline cellulose (MCC) was extracted from empty fruit bunch (EFB) with alkaline treatment, bleaching and acid hydrolysis treatment and its properties were compared with commercial MCC. Two conditions were optimized in this study which are fiber consistency and sodium hydroxide (NaOH) concentration in alkaline pretreatment. The obtained optimum consistency and alkaline concentration are 5% and 20%respectively. The physicochemical and morphological characteristics, elemental composition and size distribution of the obtained alpha cellulose and MCC were analyzed in this work. Fourier transform infrared spectroscopy (FTIR) analysis provided clear evidence that the characteristic peak of lignin and hemicellulose were absent in the spectrum of the alpha cellulose and MCC. The difference in surface morphology and aggregation between alpha cellulose, MCC and commercialized MCC were observed by scanning electron microscopy (SEM). The mean length of approximately 251.3 μm, 41.4 μm and 138.6 μm were measured for alpha cellulose, MCC and commercialized MCC respectively. Thus, the isolated MCC from EFB has a good potential to be utilized as reinforcing agent in green composites and may be a precursor for future roselle derived nanocellulose, and thus a promising subject in nanocomposite research.


2015 ◽  
Vol 9 (7) ◽  
pp. 16 ◽  
Author(s):  
Ian Eka Pramudita ◽  
Marcella Lauditta Noviana ◽  
Henky Muljana

The aim of this work is to investigate the potential used of pressurized CO2 in the pre-treatment and the enzymatic hydrolysis of waste HVS A4 paperto produce a monomeric sugars (C5 and C6 sugars) which is a precursor for bioethanol production. Prior to the utilization of waste HVS A4 paper, the microcrystalline cellulose and HVS A4 paper were first used in the experiments as model compound in order to gain better insights of the process. The experiment consists of two main parts which are the preliminary experimentsto determine the best pretreatment conditionsbetween two selected pressure values (80 and 100 bar) at a fixed temperature (T = 75 oC) and the enzymatic hydrolysis experiments. In the latter, the microcrystalline and HVS A4 paper were hydrolyzed at different pressures (100 bar, 125 bar, and 150 bar) and at different cellulase intakes (1% (v/v), 3% (v/v), and 5% (v/v)) with a fixed temperature (50°C). The hydrolyzed products were analyzed with a High Performance Liquid Chromatography (HPLC) to quantify the monomeric sugars and to determine the presence of the side products (furfural, HMF and levulinic acid). Within the experimental range, a maximum glucose concentration of 7602.35 ppm and 4560.79 ppm are obtained for microcrystalline and HVS A4 paper, respectively. In addition, there are no furfural, HMF and levulinic acid detected in the products This study shows a potential used of pressurized CO2 in the pretreatment and enzymatic hydrolysis of the model compound and gives a better insight for further application.


2021 ◽  
Vol 57 (2) ◽  
pp. 84-92
Author(s):  
Teodora DRĂGAN ◽  
◽  
Luca Liviu RUS ◽  
A. MUNTEAN ◽  
A.L. VONICA-TINCU ◽  
...  

This study aims to develop and validate NIR-chemometric methods for quantifying the API (quetiapine) and two excipients in extended-release tablets without sample preparation. The calibration samples were prepared following an experimental design with three variables (quetiapine, HPMC and microcrystalline cellulose) and five levels (concentration 80-90-100-110-120% of API). The validation set included three concentration levels (90-100-110%). The best calibration algorithms have used the same pre-treatment method (SNV), and different factors: 7 PLS factors (R² -0,966 and RMSEP-6,84) for quetiapine, 8 PLS factors (R²-0,927 and RMSEP 6,84) for HPMC and 3 PLS factors (R²-0,983 and RMSEP-7,26) for microcrystalline cellulose. The methods were fully validated according to the ICH guidance using these calibration models. Regarding the trueness of the methods, the recovery was between 98.51 and 99.43 for quetiapine, between 98.61 and 100.85 for HPMC, and between 100.61 and 101.78 for microcrystalline cellulose. According to data obtained, the accuracy profile was ± 5 for quetiapine and HPMC, and ± 6 for microcrystalline cellulose. Linearity profile was also in establish intervals at accuracy and the R2 value was 0.983 for quetiapine, 0.948 for HPMC and 0.997 for microcrystalline cellulose. In conclusion, the developed NIR-chemometric methods have suitable reproducibility, accuracy, linearity and can be used for quantitative characterisation of extended-release tablets with quetiapine, with any sample preparation.


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