scholarly journals Quantitative characterisation of extended-release tablets with quetiapine using NIR-chemometric methods

2021 ◽  
Vol 57 (2) ◽  
pp. 84-92
Author(s):  
Teodora DRĂGAN ◽  
◽  
Luca Liviu RUS ◽  
A. MUNTEAN ◽  
A.L. VONICA-TINCU ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Microcrystalline Cellulose ◽  
Extended Release ◽  
Treatment Method ◽  
Chemometric Methods ◽  
Calibration Models ◽  
Quantitative Characterisation ◽  
Calibration Samples ◽  
Pre Treatment ◽  
Validation Set

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.

EELS characterization of “Smut” layer films on steel surface prepared for chrome plating by anodic etching

1995 ◽  
Vol 53 ◽  
pp. 538-539
Author(s):  
E Y. Wang ◽  
J. T. Cherian ◽  
A. Madsen ◽  
R. M. Fisher
Keyword(s):  
Steel Surface ◽  
Surface Preparation ◽  
Treatment Method ◽  
Chrome Plating ◽  
Transmission Electron ◽  
Alloy Steels ◽  
Pre Treatment ◽  
Hard Chrome ◽  
Electron Energy Loss

Many steel parts are electro-plated with chromium to protect them against corrosion and to improve their wear-resistance. Good adhesion of the chrome plate to the steel surface, which is essential for long term durability of the part, is extremely dependent on surface preparation prior to plating. Recently, McDonnell Douglas developed a new pre-treatment method for chrome plating in which the steel is anodically etched in a sulfuric acid and hydrofluoric acid solution. On carbon steel surfaces, this anodic pre-treatment produces a dark, loosely adhering material that is commonly called the “smut” layer. On stainless steels and nickel alloys, the surface is only darkened by the anodic pre-treatment and little residue is produced. Anodic pre-treatment prior to hard chrome plating results in much better adherence to both carbon and alloy steels.We have characterized the anodic pre-treated steel surface and the resulting “smut” layer using various techniques including electron spectroscopy for chemical analysis (ESCA) on bulk samples and transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) on stripped films.

scholarly journals The effect of drying temperature on the properties of gelatin from carps (Cyprinus carpio) skin

2019 ◽  
Vol 37 (No. 4) ◽  
pp. 246-251 ◽  
Author(s):  
Joanna Tkaczewska ◽  
Maciej Wielgosz ◽  
Piotr Kulawik ◽  
Marzena Zajac
Keyword(s):  
Cyprinus Carpio ◽  
Freeze Drying ◽  
Treatment Method ◽  
Thermal Hydrolysis ◽  
Gel Properties ◽  
Drying Temperature ◽  
Freeze Dried ◽  
Different Temperatures ◽  
Pre Treatment ◽  
Hydrolysis Of

The influence of drying temperature on the characteristics and gel properties of gelatine from Cyprinus carpio L. skin was studied. Gelatine was extracted from the carp skin using NaOH and ethanol pre-treatment method, extracted in water in 45°C and then dried in 4 different temperatures: 50, 70, 80°C and freeze-dried. The  electrophoresis and functional properties of gelatines were investigated. Freeze drying allowed to obtain a high gelling force, and all other methods did not give satisfactory results. The proteins in gelatines dried at higher temperatures separated by electrophoresis gave severely blurred bands. It may be explained by thermal hydrolysis of collagen fibrils. Freeze drying is the only effective method for drying this product, which can be used in industry.

Development of an MSFIA-MPFS pre-treatment method for radium determination in water samples

Talanta ◽  
2007 ◽  
Vol 71 (3) ◽  
pp. 1172-1179 ◽  
Author(s):  
Y. Fajardo ◽  
E. Gómez ◽  
F. Garcias ◽  
V. Cerdà ◽  
M. Casas
Keyword(s):  
Water Samples ◽  
Treatment Method ◽  
Pre Treatment

scholarly journals Novel pre-treatment method for seawater reverse osmosis: Fibre media filtration

Desalination ◽  
2010 ◽  
Vol 250 (2) ◽  
pp. 557-561 ◽  
Author(s):  
J.J. Lee ◽  
M.A.H. Johir ◽  
K.H. Chinu ◽  
H.K. Shon ◽  
S. Vigneswaran ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Treatment Method ◽  
Seawater Reverse Osmosis ◽  
Pre Treatment

Fabrication and characterization of composite MoS2-TiO2 coating material

2021 ◽  
pp. 095440622110157
Author(s):  
Avinash V Borgaonkar ◽  
Ismail Syed ◽  
Shirish H Sonawane
Keyword(s):  
Bond Strength ◽  
Treatment Method ◽  
Optical Microscope ◽  
Scratch Resistance ◽  
Substrate Material ◽  
Coating Film ◽  
Tribological Behaviour ◽  
Molybdenum Disulphide ◽  
Before And After ◽  
Pre Treatment

Molybdenum disulphide (MoS2) is a popularly used solid lubricant in various applications due to its superior tribological behaviour. However, it possesses poor wear resistance which requires further improvement. In the present study efforts have been made to enhance the tribological properties of pure MoS2 coating film by doping TiO2 nanoparticles as a reinforcement material. The Manganese phosphating is selected as a pre-treatment method to improve the bond strength between coating and substrate. The coating is bonded with the substrate material employing sodium silicate as a binder. The effects of wt. % of TiO2 onto the mechanical properties of composite MoS2-TiO2 coating such as hardness and bond strength have been studied. In addition coating microstructure before and after experimental test was studied using optical microscope and scanning electron microscope. It was also found that with increase in wt. % addition of TiO2 upto 15% into MoS2 base matrix, the hardness of coating increases proportionally. Beyond 15 wt. % addition of TiO2, the coating becomes brittle in nature. This leads to reduction in the scratch resistance.

Evaluation and development of a novel pre-treatment method for mulberry leaves to enhance their bioactivity via enzymatic degradation of GAL-DNJ to DNJ

2021 ◽  
Author(s):  
Soo Takasu ◽  
Isabella Supardi Parida ◽  
Yoshihiro Kojima ◽  
Toshiyuki Kimura ◽  
Kiyotaka Nakagawa
Keyword(s):  
Enzymatic Degradation ◽  
Treatment Method ◽  
Mulberry Leaves ◽  
Pre Treatment ◽  
Hydrolysis Of

We demonstrated the conversion of GAL-DNJ into DNJ improves mulberry leaves bioavailability and constructed a novel enzymatic-based method to induce the hydrolysis of GAL-DNJ to DNJ.

scholarly journals Kinetic Behaviour of Pancreatic Lipase Inhibition by Ultrasonicated A. malaccensis and A. subintegra Leaves of Different Particle Sizes

2020 ◽  
Vol 15 (3) ◽  
pp. 818-828
Author(s):  
Miradatul Najwa Muhd Rodhi ◽  
Fazlena Hamzah ◽  
Ku Halim Ku Hamid
Keyword(s):  
Particle Size ◽  
Gallic Acid ◽  
Pancreatic Lipase ◽  
Crude Extract ◽  
Competitive Inhibition ◽  
Treatment Method ◽  
Crude Extracts ◽  
Pre Treatment ◽  
Pancreatic Lipase Inhibition ◽  
Lipase Inhibition

Gallic acid and quercetin equivalent were determined in the crude extract of matured leaves Aquilaria malaccensis and Aquilaria subintegra. The leaves of both Aquilaria species were dried at 60 °C for 24 hours, ground and sieved into particle size of 250, 300, 400, 500, and 1000 µm. Then, each particle size of leaves was soaked in distilled water with a ratio of 1:100 (w/v) for 24 hours and undergoes the pre-treatment method by using ultrasonicator (37 kHz), at the temperature of 60 °C for 30 minutes. The crude extracts were obtained after about 4 hours of hydrodistillation process. The highest concentration of gallic acid and quercetin equivalent was determined in the crude extract from the particle size of 250 µm. The kinetics of pancreatic lipase inhibition was further studied based using the Lineweaver-Burk plot, wherein the concentration of p-NPP as the substrate and pancreatic lipase were varied. Based on the formation of the lines in the plot, the crude leaves extract of both Aquilaria species exhibit the mixed-inhibition on pancreatic lipase, which indicates that in the reaction, the inhibitors were not only attached to the free pancreatic lipase, but also to the pancreatic lipase-(p-NPP) complex. The reaction mechanism was similar to non-competitive inhibition; however the value of dissociation constant, Ki, for both inhibition pathways was different. The inhibition shows an increment in Michaelis-Menten constant (Km) and a reduction in the maximum pancreatic lipase activity (Vm) compared to the reaction without Aquilaria spp. crude extracts (control). This proved that the inhibition occurred in this reaction. Copyright © 2020 BCREC Group. All rights reserved 

scholarly journals INVESTIGATION ON PRE-TREATMENT PROCESS IN MICROCRYSTALLINE CELLULOSE (MCC) FROM OIL PALM EMPTY FRUIT BUNCH (EFB)

2018 ◽  
Vol 3 (1) ◽  
pp. 87-96
Author(s):  
Muhammad Arif Fahmi Supian ◽  
Khairatun Najwa Mohd Amin ◽  
Saidatul Shima Jamari ◽  
Shahril Mohamad
Keyword(s):  
Microcrystalline Cellulose ◽  
Morphological Characteristics ◽  
Alkaline Treatment ◽  
Empty Fruit Bunch ◽  
Characteristic Peak ◽  
Reinforcing Agent ◽  
Good Potential ◽  
The Mean ◽  
The Difference ◽  
Pre Treatment

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.

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