scholarly journals METHODS OF METOPROLOL ANALYSIS IN DRUGS AND BIOLOGICAL FLUIDS: REVIEW AND SUGGESTIONS

Author(s):  
M. M. Horyn ◽  
L. S. Logoyda

Background. Analytical method is increasingly implemented into fundamental pharmaceutical chemistry and analysis, considering their high sensitivity, accuracy, specificity and expressiveness. Objective. Metoprolol’s analytical method development was the research goal. Methods. The sources were world recognized journals (1990-2019) and key words used as filter were “metoprolol”, “spectrophotometry” “high-performance liquid chromatography, HPLC”, “quantitative analysis”, “validation”. Results. Chromatographic methods of analysis have the highest specificity and objectivity and allow qualitative and quantitative determination of Active Pharmaceutic Ingredient (API) in combined dosage forms and biological fluids without prior components separation. The main disadvantage of the described API analysis methods is long terms from the beginning of chromatography to API release and specific solvents used as the mobile phase in HPLC. New methods development and selection such chromatographic conditions that provide high speed and high efficiency at lower pressure of the system are essential. Also, the reduction of analysis time is achieved by simplifying the conditions for sample preparation. Conclusions. Analysts are constantly working on developing new analysis methods and their optimization in order to save time and consumables, which also ensures the efficiency of the developed method. There is no monograph on the substance or dosage forms of metoprolol in SPhU. Therefore, some of the developed methods should be suggested for the SPhU monograph, which is important for ensuring pharmacopoeial quality control of medicines in Ukraine.

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1365
Author(s):  
Tao Zheng ◽  
Zhizhao Duan ◽  
Jin Wang ◽  
Guodong Lu ◽  
Shengjie Li ◽  
...  

Semantic segmentation of room maps is an essential issue in mobile robots’ execution of tasks. In this work, a new approach to obtain the semantic labels of 2D lidar room maps by combining distance transform watershed-based pre-segmentation and a skillfully designed neural network lidar information sampling classification is proposed. In order to label the room maps with high efficiency, high precision and high speed, we have designed a low-power and high-performance method, which can be deployed on low computing power Raspberry Pi devices. In the training stage, a lidar is simulated to collect the lidar detection line maps of each point in the manually labelled map, and then we use these line maps and the corresponding labels to train the designed neural network. In the testing stage, the new map is first pre-segmented into simple cells with the distance transformation watershed method, then we classify the lidar detection line maps with the trained neural network. The optimized areas of sparse sampling points are proposed by using the result of distance transform generated in the pre-segmentation process to prevent the sampling points selected in the boundary regions from influencing the results of semantic labeling. A prototype mobile robot was developed to verify the proposed method, the feasibility, validity, robustness and high efficiency were verified by a series of tests. The proposed method achieved higher scores in its recall, precision. Specifically, the mean recall is 0.965, and mean precision is 0.943.


2021 ◽  
Vol 33 (7) ◽  
pp. 1692-1698
Author(s):  
S.S. Jadiya ◽  
N. Upmanyu ◽  
S. Arulmozhi ◽  
V. Jain ◽  
S. Sankaran ◽  
...  

In present study, an advanced, simple and a rapid reverse phase high performance liquid chromatography (RP-HPLC) method was developed for the quantitative determination of sulfasalazine in rabbit plasma. Sulfasalazine was separated using Chromatopak C-18 basic peerless (250 mm × 4.6 mm, 5μ) column in an isocratic mode using mobile phase consisting of the mixture of 10mM Ammonium acetate pH adjusted to 4.5 and acetonitrile (70:30 v/v) with a flow rate of about 1.0 mL/min at ambient temperature. An ultra-violet detection of sulfasalazine and the internal standard was carried out at 362 nm. Both sulfasalazine and internal standard (IS, 4-hydroxy benzoate) were extracted from plasma matrices with high efficiency using a simple protein precipitation method. The method was found to be highly selective with no carryover effects. Linearity of sulfasalazine was found with the range of 2.5-100 μg/mL with the value of r2 > 0.995 a correlation coefficient. At all three quality control levels, developed bioanalytical method was found as repeatable and reproducible as well. The average recoveries of sulfasalazine from plasma were in the range of 95.59-97.16%. The bioanalytical samples showed good and acceptable stability of sulfasalazine solution at different storage, packaging and handling conditions. Hence, in conclusion, the validated and developed HPLC-UV method could be effectively utilized for determination of sulfasalazine in pharmacokinetic studies involving novel formulations.


2018 ◽  
Vol 224 ◽  
pp. 02019 ◽  
Author(s):  
Vladimir Mazur

Simplicity and high efficiency of a wheeled mover as a mechanism for converting rotational motion into a translatory one have conditioned its wide application in overland machines including motor vehicles. However a wheel with a non-pneumatic tyre (NPT) has a sufficient drawback lying in termination of a wheeled machine movement at the excess air pressure loss. Moreover, the loss of excess air pressure in a pneumatic tyre of traditional design at high speed of movement of a motor vehicle can lead to a traffic accident with heavy consequences. The stop of a motor vehicle to change a wheel on a heavy traffic roadway or roadside also poses a threat. These reasons determine the necessity of both well-known design improvements and search for the new wheeled mover design solutions to enhance a motor vehicle safety, the use of wheels with non-pneumatic tyres of elastic polymeric materials being one of them. Safety enhancement by means of non-pneumatic tyre use along with keeping the high performance of wheeled machine operational properties, is an important scientific and technical task that determines the research urgency.


Author(s):  
Akiful Haque M ◽  
Shanthi Priya D K ◽  
Dibyalochan Mohanty ◽  
Vasudha Bakshi ◽  
Narender Boggula

Objective: The objective of the present investigation was to develop a novel, simple, and economic method for the estimation of amlodipine in positive ion mode in human plasma using amlodipine maleate d4 as an internal standard.Methods: The chromatographic separation was performed on Zorbax SB, C18, 50 mm*4.6 mm, and 3.5 mm. The mobile phase was prepared with a mixture of 5 mm ammonium acetate in 0.1% formic acid: High performance liquid chromatographic (HPLC) grade methanol:HPLC grade acetonitrile (40:30:30) that run isocratically at the flow rate of 0.700 ml/min and run time at 2.50 min.Results: The analytical method is valid for the estimation of amlodipine, in human plasma over a range of 0.100 ng/ml–9.990 ng/ml with the detection of amlodipine m/z - 409.10 (parent) and 238.00 (product), and internal standard Amlodipine Maleate d4 m/z - 413.20 (parent), and 238.00 (product) in positive ion mode. The results of carryover test, matrix effect, linearity, precision and accuracy, stabilities, dilution integrity, and run size evaluation test presented in this report are within the acceptance range.Conclusion: A sensitive method for the separation and determination of amlodipine in plasma has been developed based on solid-phase extraction with disposable extraction cartridges in combination with LC and mass spectrophotometers (MS/MS).


2005 ◽  
Vol 11 (2) ◽  
pp. 189-197 ◽  
Author(s):  
J. David Pinkston

Mobile phases in supercritical fluid chromatography (SFC) have low viscosities and high diffusion coefficients with respect to those of traditional high-performance liquid chromatography (HPLC). These properties allow higher mobile phase flow rates and/or longer columns in SFC, resulting in rapid analyses and high efficiency separations. In addition, chiral SFC is becoming especially popular. Mass spectrometry (MS) is arguably the most popular “informative” detector for chromatographic separations. Most SFC/MS is performed with atmospheric pressure ionization (API) sources. Unlike LC/MS, the interface between the SFC column and the API source must allow control of the downstream (post-column) pressure while also providing good chromatographic fidelity. Here, we compare and contrast the popular interfacing approaches. Some are simple, such as direct effluent introduction with no active back pressure regulator (BPR) in high-speed bioanalytical applications. The pressure-regulating fluid interface is more versatile and provides excellent chromatographic fidelity, but is less user friendly. The pre-BPR-split interface and an interface which provides total flow introduction with a mechanical BPR are good compromises between user friendliness and performance and have become the most popular among practitioners. Applications of SFC/MS using these various interfaces are also discussed.


2007 ◽  
Vol 280-283 ◽  
pp. 1391-1394 ◽  
Author(s):  
Zhi Hong Li ◽  
Yong Hong Zhang ◽  
Y.M. Zhu ◽  
Zheng Fang Yang

Cubic boron nitride(CBN) is a superhard materials with many advantages and many uses. Vitrified bond CBN grinding tool is a promising abrasive tool of high performance used for high speed, high efficiency, high precision grinding with lower grinding cost and less environment pollution. Sintering of vitrified bond CBN grinding tool was investigated in this paper. The results showed that practical sintering temperature of this tool was much lower than the initial oxidation temperature of CBN particle measured by comprehensive thermal analysis. The upper limit of sintering temperature should be determined by taking account of the thermal analyzing results, heating process of CBN and its change in strength and structure. Within the sintering temperature range of the vitrified bond, relatively higher sintering temperature was beneficial to the strength of bond bridge and the holding strength between bond and CBN abrasive particles. CBN tool sintered at relatively lower temperature tended to fracture through the bond bridge, while the one sintered at higher temperature tended to fracture along the boundary between CBN abrasive grain and vitrified bond.


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