System of Standard Solutions

2021 ◽  
pp. 237-371
Author(s):  
Isak Bukhman
Keyword(s):  
Standard Solutions

Comparison of UV- and Derivative-Spectrophotometric and HPTLC UVDensitometric Methods for the Determination of Amrinone and Milrinone in Bulk Drugs

2020 ◽  
Vol 16 (3) ◽  
pp. 246-253
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Stefan Kruszewski
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Low Cost ◽  
Uv Spectra ◽  
Derivative Spectrophotometry ◽  
Therapeutic Monitoring ◽  
Bulk Drug ◽  
Layer Chromatography ◽  
Standard Solutions

Background: Spectrophotometry and thin layer chromatography have been commonly applied in pharmaceutical analysis for many years due to low cost, simplicity and short time of execution. Moreover, the latest modifications including automation of those methods have made them very effective and easy to perform, therefore, the new UV- and derivative spectrophotometry as well as high performance thin layer chromatography UV-densitometric (HPTLC) methods for the routine estimation of amrinone and milrinone in pharmaceutical formulation have been developed and compared in this work since European Pharmacopoeia 9.0 has yet incorporated in an analytical monograph a method for quantification of those compounds. Methods: For the first method the best conditions for quantification were achieved by measuring the lengths between two extrema (peak-to-peak amplitudes) 252 and 277 nm in UV spectra of standard solutions of amrinone and a signal at 288 nm of the first derivative spectra of standard solutions of milrinone. The linearity between D252-277 signal and concentration of amironone and 1D288 signal of milrinone in the same range of 5.0-25.0 μg ml/ml in DMSO:methanol (1:3 v/v) solutions presents the square correlation coefficient (r2) of 0,9997 and 0.9991, respectively. The second method was founded on HPTLC on silica plates, 1,4-dioxane:hexane (100:1.5) as a mobile phase and densitometric scanning at 252 nm for amrinone and at 271 nm for milrinone. Results: The assays were linear over the concentration range of 0,25-5.0 μg per spot (r2=0,9959) and 0,25-10.0 μg per spot (r2=0,9970) for amrinone and milrinone, respectively. The mean recoveries percentage were 99.81 and 100,34 for amrinone as well as 99,58 and 99.46 for milrinone, obtained with spectrophotometry and HPTLC, respectively. Conclusion: The comparison between two elaborated methods leads to the conclusion that UV and derivative spectrophotometry is more precise and gives better recovery, and that is why it should be applied for routine estimation of amrinone and milrinone in bulk drug, pharmaceutical forms and for therapeutic monitoring of the drug.

scholarly journals GASOMETRIC CONTROL OF STANDARD SOLUTIONS FOR THE PALMER HEMOGLOBIN METHOD

1929 ◽  
Vol 84 (1) ◽  
pp. 211-216
Author(s):  
Donald D. Van Slyke ◽  
Alma Hiller
Keyword(s):  
Standard Solutions

scholarly journals Modeling of non-standard geometry of energy-efficient building facades

2019 ◽  
Vol 91 ◽  
pp. 05024
Author(s):  
Natalia Knyazeva ◽  
Vladislav Larin
Keyword(s):  
Energy Efficient ◽  
Construction Projects ◽  
Parametric Modeling ◽  
Labor Costs ◽  
Building Facades ◽  
Standard Geometry ◽  
Energy Efficient Building ◽  
Standard Solutions

This article describes the approach of parametric modeling using modern software. This decision should help to change the already established rules for building BIM models. This approach became the basis of the idea of using parametric modeling for two main groups in the modern modeling of construction projects: modeling of the architectural appearance of the building and structures. This method can significantly reduce labor costs, and it also can be used to implement non-standard solutions in the design energy-efficient building facades.

Determination of adenine nucleotides by the modified method of high-performance liquid chromatography

2021 ◽  
Vol 66 (3) ◽  
pp. 172-176
Author(s):  
Lyubov Borisovna Kalikova ◽  
E. R. Boyko
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Adenine Nucleotides ◽  
Release Time ◽  
Chromatography Method ◽  
Rp Hplc ◽  
Standard Solutions

Adenine nucleotides (ATP, ADP and AMP) play a central role in the regulation of metabolism and energy: they provide the energy balance of the cell, determine its redox state, act as allosteric effectors of a number of enzymes, modulate signaling and transcription factors and activate oxidation or biosynthesis substrates. A large number of methods have been developed to determine the level of ATP, ADP and AMP, but the most universal and effective method for the separation and analysis of complex mixtures is the reversed-phase high-performance liquid chromatography method (RP-HPLC). The aim of this study is to determine the optimal conditions for the qualitative separation and quantitative determination of standard solutions of ATP (1 mmol/l), ADP (0,5 mmol/l) and AMP (0,1 mmol/l) by RP-HPLC. The degree of separation of adenine nucleotides was estimated by the time of peak output in the chromatogram. To achieve the goal, the following tasks were set: assess the effect of the temperature of the analysis on the separation and change of the release time of the analytes in the chromatogram; determine the most optimal composition of the mobile phase for the separation of ATP, ADP and AMP in the chromatogram (the content of the organic solvent in the solution); to identify the effect of pH of the mobile phase on the separation of standard solutions of adenine nucleotides; set the optimal molarity of the mobile phase for the separation of ATP, ADP and AMP in the chromatogram. It was found that the temperature of the analysis does not affect the quality of peak separation, while the composition and pH of the mobile phase have a significant effect on the complete and clear separation of the studied nucleotides in the chromatogram. It was determined that the analysis temperature of 37°C and the mobile phase of 0.05 M KH2PO4 (pH 6.0) are optimal for separating the peaks of adenine nucleotides.

A ‘tailor-made’ ensemble – an outline of ensemble music-making at a primary music school

2020 ◽  
Vol 7 (1(11)) ◽  
pp. 143-154
Author(s):  
Anna Pawelec
Keyword(s):  
Experienced Teacher ◽  
Music School ◽  
Music Making ◽  
Current Topic ◽  
Standard Solutions

Music-making in ensembles at a primary music school is an invariably current topic, though still discussed definitely too rarely. Pedagogues teaching both the youngest and a little older pupils recognize the value of collective singing, playing or moving to music. They indicate a number of benefits drawn from ensemble music-making. In this article, the Author, who is an experienced teacher conducting school ensembles for many years, based on her own pedagogical experience, outlines the potential behind non-standard solutions as regards line-ups of children’s ensembles. She also discusses the question of repertoire for unconventional ensembles, indicating selected options of sourcing the pieces.

scholarly journals Higher Dialysate Matrix Metalloproteinase-2 Levels are Associated with Peritoneal Membrane Dysfunction

2016 ◽  
Vol 36 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Yeoungjee Cho ◽  
David W. Johnson ◽  
David A. Vesey ◽  
Carmel M. Hawley ◽  
Elaine M. Pascoe ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Primary Outcome ◽  
Incidence Rate Ratio ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Matrix Metalloproteinase 2 ◽  
Peritoneal Membrane ◽  
Low Glucose ◽  
Multilevel Linear Regression ◽  
Peritoneal Solute Transport Rate ◽  
Standard Solutions

♦ Background Peritoneal dialysis (PD) patients develop progressive and cumulative peritoneal injury with longer time spent on PD. The present study aimed to a) describe the trend of peritoneal injury biomarkers, matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1), in incident PD patients, b) to explore the capacity of dialysate MMP-2 to predict peritoneal solute transport rate (PSTR) and peritonitis, and c) to evaluate the influence of neutral pH, low glucose degradation product (GDP) PD solution on these outcomes. ♦ Methods The study included 178 participants from the balANZ trial who had at least 1 stored dialysate sample. Changes in PSTR and peritonitis were primary outcome measures, and the utility of MMP-2 in predicting these outcomes was analyzed using multilevel linear regression and multilevel Poisson regression, respectively. ♦Results Significant linear increases in dialysate MMP-2 and TIMP-1 concentrations were observed ( p < 0.001), but neither was affected by the type of PD solutions received (MMP-2: p = 0.07; TIMP-1: p = 0.63). An increase in PSTR from baseline was associated with higher levels of MMP-2 ( p = 0.02), and the use of standard solutions over longer PD duration ( p = 0.001). The risk of peritonitis was independently predicted by higher dialysate MMP-2 levels (incidence rate ratio [IRR] per ng/mL 1.01, 95% confidence interval [CI] 1.005 – 1.02, p = 0.002) and use of standard solutions (Biocompatible solution: IRR 0.45, 95% CI 0.24 – 0.85, p = 0.01). ♦ Conclusion Dialysate MMP-2 and TIMP-1 concentrations increased with longer PD duration. Higher MMP-2 levels were associated with faster PSTR and future peritonitis risk. Administration of biocompatible solutions exerted no significant effect on dialysate levels of MMP-2 or TIMP-1, but did counteract the increase in PSTR and the risk of peritonitis associated with the use of standard PD solutions. This is the first longitudinal study to examine the clinical utility of MMP-2 as a predictor of patient-level outcomes.

Preparation of standard solutions

1973 ◽  
Vol 50 (10) ◽  
pp. 679 ◽  
Author(s):  
B. W. Smith ◽  
M. L. Parsons
Keyword(s):  
Standard Solutions

scholarly journals Anti- Parkinsonian Drug Estimation by RP-HPLC

2021 ◽  
pp. 14-25
Author(s):  
Rama Rao Nadendla ◽  
Patchala Abhinandana
Keyword(s):  
Mobile Phase ◽  
Drug Testing ◽  
High Sensitivity ◽  
Calibration Plot ◽  
Simultaneous Estimation ◽  
Pharmaceutical Sciences ◽  
Simple Method ◽  
Rp Hplc ◽  
Run Time ◽  
Standard Solutions

Aim: The main aim of the current study is to give best and simple method for the estimation of antiparkinsonian drugs named Carbidopa, levodopa and entacapone. Study Design:  Simultaneous estimation of Carbidopa, levodopa and entacapone was performed by using Quadrapumped (SHIMADZU Prominance-i, LC-2030C) RP-HPLC equipped with PDA detector. Place and Duration of Study: Chalapathi Drug Testing Laboratory, Chalapathi Institute Of Pharmaceutical Sciences, Lam, Guntur-522034, Andhra Pradesh, India during the period of August 2019 to February 2020. Methodology: The assets of the study can determined as the process of qualification and quantification was done on SHIMADZU Prominance-i, LC-2030C system equipped with Phenomenex ODS (150 x 4.6 mm, 5μm) column and mobile phase was optimized using combination of acetonitrile and 0.1% ortho phosphoric acid in the ration of 50:50 v/v at a flow rate 1.0 ml/min. The wavelength was set as 270nm at ambient temperature by injecting 20µl of solution and the run time was fixed for 5 min. Results: Calibration plot shown best regression over the concentration range of 5-160 µg/ml of Carbidopa, Levodopa and Entacapone standard solutions. The LOD and LOQ were found to be 0.85 and 2.54 µg/ml for Entacapone, 0.24 and 0.71 µg/ml for Levodopa, 0.14 and 0.43 µg/ml for Carbidopa respectively. The accuracy of the proposed method was determined by performing recovery studies and was found to be between 98-102%. The repeatability testing for both sample and standard solutions was found as %RSD<2.0% which is within the acceptable limits showing that the method is precise as well. The proposed method was successfully applied for the marketed formulations of Carbidopa, Levodopa and Entacapone tablets. In addition the main feature of proposed method is economic and eco-friendly with less retention time around 5.0 min. Conclusion: Including all the optimized method parameters and statistical results given it can be concluded as a new, simple, sensitive, precise and accurate economical analytical method was developed and validated by RP-HPLC for the detection and quantification of Carbidopa, Levodopa and Entacapone which can be applied to the marketed formulation where there are no official compendial methods reported for this particular combination. The high sensitivity (LOD), mobile phase utilized and run time (=5) can be determined as an important features for this proposal.

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