scholarly journals Stability of Ready-to-Administer and Ready-to-Use Epinephrine and Norepinephrine Injection Solutions

2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Rita Marina Heeb ◽  
Bettina Stollhof ◽  
Julia Reichhold ◽  
Judith Thiesen ◽  
Irene Krämer
Keyword(s):  
Shelf Life ◽  
Elevated Temperatures ◽  
Reversed Phase ◽  
Type I ◽  
Long Term Stability ◽  
Intensive Care Patients ◽  
Pharmacy Department ◽  
Physicochemical Stability ◽  
Light Protection ◽  
The University

AbstractBackgroundIn the University Medical Centre Mainz, standard concentrations are defined for medicinal products to be administered by continuous injection with syringe pumps in adult intensive care patients. The objective of this study was to evaluate the physicochemical stability of ready-to-use and ready-to-administer preparations containing Epinephrine (E) and Norepinephrine (NE) in standardized concentrations and prepared batch wise in the pharmacy department as basis for assigning shelf-lives.MethodsE 20 µg/mL and NE 10 µg/mL in disposable syringes and NE 40, 100, 200, 400 µg/ml in 50 ml amber type I glass vials were prepared batch wise and the concentrations were analyzed by stability-indicating, validated reversed-phase HPLC-PDA assays. Test solutions for long-term stability studies were stored under refrigeration (2–8 °C) for 6–12 months or at elevated temperatures (21–27 °C) light protected for up to 6 months or without light protection for up to one month. Osmolality and pH were measured on predefined intervals.ResultsThe concentrations of E in 50 mL syringes and NE in 10 mL syringes remained unchanged over a period of 6 months when stored at 2–8 °C. NE preparations of different concentrations prepared in amber glass vials remained stable over a study period of 12 months. At RT the shelf-life decreased to about 6 months and the exposure to mixed daylight at RT caused loss of stability in only few days.ConclusionsBatch wise preparation of ready-to-administer (RTA) preparations containing 20 µg/mL E or 10 µg/mL NE in disposable syringes as well as ready-to-use (RTU) preparations containing 40, 100, 200 and 400 µg/mL NE was successfully implemented in a pharmacy department. Storage of the preparations at refrigerated temperatures is required to obtain acceptable shelf-lives of 6–12 months. Elevated temperatures and especially exposure to mixed daylight significantly decreased the shelf life.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

scholarly journals CO Detection Investigation at High Temperature by SiC MISFET Metal/Oxide Gas Sensors

Proceedings ◽  
2021 ◽  
Vol 56 (1) ◽  
pp. 41
Author(s):  
Lida Khajavizadeh ◽  
Anita Lloyd Spetz ◽  
Mike Andersson
Keyword(s):  
High Temperature ◽  
Gas Sensors ◽  
Elevated Temperatures ◽  
Long Term Stability ◽  
Stability Performance ◽  
Catalytic Metal ◽  
Co Detection ◽  
Effect Transistor ◽  
Metal Oxide Gas Sensors

In order to investigate the necessary device improvements for high-temperature CO sensing with SiC metal insulator semiconductor field effect transistor (MISFET)-based chemical gas sensors, devices employing, as the gas-sensitive gate contact, a film of co-deposited Pt/Al2O3 instead of the commonly used catalytic metal-based contacts were fabricated and characterized for CO detection at elevated temperatures and different CO and O2 levels. It can be concluded that the sensing mechanism at elevated temperatures correlates with oxygen removal from the sensor surface rather than the surface CO coverage as observed at lower temperatures. The long-term stability performance was also shown to be improved compared to that of previously studied devices.

Maturation process and characterization of a novel thermostable and halotolerant subtilisin-like protease with high collagenolytic but low gelatinolytic activity

2021 ◽  
Author(s):  
Kui Zhang ◽  
Qianqian Huang ◽  
Yu Li ◽  
Lanhua Liu ◽  
Xiao-Feng Tang ◽  
...  
Keyword(s):  
High Temperatures ◽  
Type I Collagen ◽  
Elevated Temperatures ◽  
Catalytic Domain ◽  
Ion Pairs ◽  
Gelatinolytic Activity ◽  
Type I ◽  
Fish Scale ◽  
Collagenolytic Proteases ◽  
Collagenolytic Protease

Enzymatic degradation of collagen is of great industrial and environmental significance; however, little is known about thermophile-derived collagenolytic proteases. Here, we report a novel collagenolytic protease (TSS) from thermophilic Brevibacillus sp. WF146. The TSS precursor comprises a signal peptide, an N-terminal propeptide, a subtilisin-like catalytic domain, a β-jelly roll (βJR) domain, and a prepeptidase C-terminal (PPC) domain. The maturation of TSS involves a stepwise autoprocessing of the N-terminal propeptide and the PPC domain, and the βJR rather than the PPC domain is necessary for correct folding of the enzyme. Purified mature TSS displayed optimal activity at 70°C and pH 9.0, a half-life of 1.5 h at 75°C, and an increased thermostability with rising salinity up to 4 M. TSS possesses an increased number of surface acidic residues and ion pairs, as well as four Ca 2+ -binding sites, which contribute to its high thermostability and halotolerance. At high temperatures, TSS exhibited high activity toward insoluble type I collagen and azocoll, but showed a low gelatinolytic activity, with a strong preference for Arg and Gly at the P1 and P1’ positions, respectively. Both the βJR and PPC domains could bind but not swell collagen, and thus facilitate TSS-mediated collagenolysis via improving the accessibility of the enzyme to the substrate. Additionally, TSS has the ability to efficiently degrade fish scale collagen at high temperatures. IMPORTANCE Proteolytic degradation of collagen at high temperatures has the advantages of increasing degradation efficiency and minimizing the risk of microbial contamination. Reports on thermostable collagenolytic proteases are limited, and their maturation and catalytic mechanisms remain to be elucidated. Our results demonstrate that the thermophile-derived TSS matures in an autocatalytic manner, and represents one of the most thermostable collagenolytic proteases reported so far. At elevated temperatures, TSS prefers hydrolyzing insoluble heat-denatured collagen rather than gelatin, providing new insight into the mechanism of collagen degradation by thermostable collagenolytic proteases. Moreover, TSS has the potential to be used in recycling collagen-rich wastes such as fish scales.

scholarly journals Limitations and Challenges in the Stability of Cysteamine Eye Drop Compounded Formulations

2021 ◽  
Vol 15 (1) ◽  
pp. 2
Author(s):  
Cristina Martín-Sabroso ◽  
Mario Alonso-González ◽  
Ana Fernández-Carballido ◽  
Juan Aparicio-Blanco ◽  
Damián Córdoba-Díaz ◽  
...  
Keyword(s):  
Shelf Life ◽  
Stability Study ◽  
Eye Drops ◽  
Microbiological Analysis ◽  
Nitrogen Gas ◽  
Long Term Stability ◽  
Main Degradation Product ◽  
The Stability ◽  
Unstable Molecule

Accumulation of cystine crystals in the cornea of patients suffering from cystinosis is considered pathognomonic and can lead to severe ocular complications. Cysteamine eye drop compounded formulations, commonly prepared by hospital pharmacy services, are meant to diminish the build-up of corneal cystine crystals. The objective of this work was to analyze whether the shelf life proposed for six formulations prepared following different protocols used in hospital pharmacies is adequate to guarantee the quality and efficacy of cysteamine eye drops. The long-term and in-use stabilities of these preparations were studied using different parameters: content of cysteamine and its main degradation product cystamine; appearance, color and odor; pH and viscosity; and microbiological analysis. The results obtained show that degradation of cysteamine was between 20% and 50% after one month of storage in the long-term stability study and between 35% and 60% in the in-use study. These data confirm that cysteamine is a very unstable molecule in aqueous solution, the presence of oxygen being the main degradation factor. Saturation with nitrogen gas of the solutions offers a means of reducing cysteamine degradation. Overall, all the formulae studied presented high instability at the end of their shelf life, suggesting that their clinical efficacy might be dramatically compromised.

scholarly journals Strategic management controlling system and its importance for SMEs in the EU

2020 ◽  
Vol 18 (3) ◽  
pp. 362-372
Author(s):  
Miroslav Pavlák ◽  
Přemysl Písař
Keyword(s):  
Strategic Management ◽  
Financial Analysis ◽  
Business Environment ◽  
The European Union ◽  
Term Stability ◽  
Long Term Stability ◽  
Controlling System ◽  
Depth Analysis ◽  
The University

The current hyper-competitive environment offers many great opportunities for small and medium-sized businesses (SMEs), but on the other hand, this business environment is also hazardous. SMEs are a significant economic power and employer in the European Union. Their competitiveness and long-term stability are a crucial factor for European cohesion and economic growth. The research aim is to design a strategic management controlling system that should be implemented to SMEs and be useful for their long-term future development. The study was conducted in 2017–2020 based on data from 403 SMEs. The PAPI method was used to collect data. The implications between defined variables controlling, ROA, turnover, financial analysis, and strategic management were explained, and the results obtained from an in-depth analysis were indicated. The research was concluded by a model of strategic management controlling system tested by experimental in-practice implementation on SMEs and verified. The model and the research findings are suitable for business practice and should support the long-term stability and development of SMEs. AcknowledgmentThe paper has been prepared within the project “Risk Management in Industry 4.0” (7427/2019/02 IGA VŠFS) using the objective oriented support for specific university research of the University of Finance and Administration.

Long-Term Stability of Aluminum Oxide Based Surface Passivation Schemes Under Illumination at Elevated Temperatures

2017 ◽  
Vol 7 (5) ◽  
pp. 1197-1202 ◽  
Author(s):  
Tim Niewelt ◽  
Wolfram Kwapil ◽  
Marisa Selinger ◽  
Armin Richter ◽  
Martin C. Schubert
Keyword(s):  
Aluminum Oxide ◽  
Elevated Temperatures ◽  
Surface Passivation ◽  
Term Stability ◽  
Long Term Stability

Automated Approaches Determine Solids Content in Drilling and Completions Fluids

2021 ◽  
Vol 73 (11) ◽  
pp. 51-52
Author(s):  
Chris Carpenter
Keyword(s):  
Elevated Temperatures ◽  
Drilling Fluid ◽  
Technical Conference ◽  
Drilling Fluids ◽  
Test Results ◽  
University Of Texas ◽  
Safety Issues ◽  
Recommended Practices ◽  
Solids Content ◽  
The University

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 201368, “Automated Solids-Content Determination in Drilling and Completions Fluids,” by Sercan Gul, SPE, Ali Karimi Vajargah, and Eric van Oort, SPE, The University of Texas at Austin, et al., prepared for the 2020 SPE Annual Technical Conference and Exhibition, originally scheduled to be held in Denver, 5–7 October. The paper has not been peer reviewed. Monitoring of low- and high-gravity-solids (LGS and HGS) content and maintaining these at ideal levels is essential for optimal drilling fluid performance, efficient hole cleaning and equivalent-circulating-density management, and prevention of failures of surface and downhole equipment during drilling. LGS and HGS monitoring in the field is currently accomplished using the API retort-kit measurement, which has certain drawbacks and is difficult to automate. In the complete paper, two new approaches are investigated to automate the LGS and HGS content measurements of drilling fluids, which potentially can replace the retort test. Introduction The conventional way to characterize LGS and HGS in the field is by using a retort-kit measurement specified in API Recommended Practices 13B-1 and 13B-2. The longevity of these tests is testament to the effectiveness of the API standards and the tests themselves in providing useful and practical field guidance. Despite their evident success, however, various downsides exist in current solids-content-testing methods. Retort-kit measurements present the following issues: - Difficulty in obtaining accurate and repeatable test results - Safety issues associated with laboratory testing at elevated temperatures (over 930°F) - Interpretive bias issues associated with test results, including the potential for deliberate manipulation of these results - Difficulty in automating the retort test for improved efficiency and safety The authors’ opinion is that automating antiquated API test protocols is not a useful practice. They write that a clean-slate approach would be better, in which a determination is made whether solids-content information can be provided in a novel and meaningful way using methods that deviate from standard API recommended practices. In the complete paper, the authors investigate a machine-learning (ML) and data-analytics method for this purpose in combination with a novel inline X-ray fluorescence (XRF) measurement method.

Formation and Properties of Porous Si Superlattices

1994 ◽  
Vol 358 ◽  
Author(s):  
M.G. Berger ◽  
R. Arens-Fischer ◽  
St. Frohnhoff ◽  
C. Dieker ◽  
K. Winz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Doping Level ◽  
Layer Structure ◽  
Optical Data ◽  
Type I ◽  
Optical Components ◽  
Porous Layers ◽  
Long Term Stability ◽  
Transmission Electron

ABSTRACTPorous silicon superlattices (PS-SL) were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), spectroscopic ellipsometry and reflectance spectroscopy. Type I superlattices were formed by periodically changing the current density during the etch process. The quality of the interface between layers of different porosity depends on the quality of the silicon substrate. Optical components such as Bragg reflectors or Fabry-Perot filters were designed using the optical data of single porous layers. A good long term stability of the layers is achieved by using thermal oxidation steps. Type II superlattices were formed on substrates with layers of alternating doping level. The more complex layer structure of these superlattices is explained by the selectivity of the etch process on the doping level.

An Experimental Study of Carbon Nanotube Reinforcements

2011 ◽  
Author(s):  
Lauren Patrin ◽  
Frank Chow ◽  
Gabriela Philippart ◽  
Feridun Delale ◽  
Benjamin Liaw ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Young's Modulus ◽  
Testing Machine ◽  
Type I ◽  
Electrical Measurements ◽  
Standard Type ◽  
Reinforcement Percentage

Due to their high strength and stiffness carbon nanotubes (CNTs) have been considered as candidates for reinforcement of polymeric resins. It is also known that the addition of CNTs to polymeric matrix results in highly conductive nanocomposites, making the material multifunctional. Most of the CNT reinforced polymeric nanocomposite systems reported in the literature have been studied at room temperature. However, in many applications, materials may be subjected from low to elevated temperatures. Thus, the aim of this research is to study CNT reinforced polypropylene (PP) specimens at room, elevated and low temperatures. ASTM standard Type I specimens manufactured via injection molding and reinforced with 0.2%, 1%, 3%, and 6% CNTs were first subjected to tensile loads in a universal testing machine at room temperature. Neat PP resin specimens were also tested to provide baseline data. The tests were repeated at −54°C (−65°F), −20°C (−4°F), 49°C (120°F) and 71°C (160°F). The results were plotted as stress-strain curves and analyzed to delineate the effect of CNT reinforcement percentage and temperature on the mechanical properties. It was noted that as the percentage of CNT reinforcement increases, the resulting nanocomposite becomes stiffer (higher Young’s modulus), has higher strength and becomes more brittle. Temperature has a drastic effect on the behavior of the nanocomposite. As the temperature increases, at a given reinforcement percentage the material becomes more ductile with significantly lower Young’s modulus and strength compared to room temperature. At lower temperatures, the nanocomposite becomes more brittle with higher stiffness and strength, but significantly reduced failure strain. Also electrical measurements were conducted on the specimens to measure their resistance. For specimens reinforced with up to 3% of CNTs no electrical conductivity was detected. As expected at 6% CNT reinforcement (which is above the approximately 4% percolation limit reported in the literature), the specimens became electrically conductive. To predict the mechanical properties obtained experimentally, a micromechanics based model is presented and compared with the experimental results.

Progress of COSMOS (CO2 Sending Method for Ocean Storage) and OACE (Ocean Abyssal Carbon Experiment)

2003 ◽  
Author(s):  
Izuo Aya ◽  
Sadahiro Namie ◽  
Kenji Yamane ◽  
Ryuji Kojima ◽  
Yasuharu Nakajima ◽  
...  
Keyword(s):  
Ocean Floor ◽  
Monterey Bay ◽  
Storage Site ◽  
Joint Research ◽  
Ambient Seawater ◽  
Long Term Stability ◽  
Liquid Co2 ◽  
The University ◽  
Research Institute

The storage of liquid CO2 at an ocean floor, one of promising measures to mitigate the global warming, requires 3500 m depth for the gravitationally stable storage, a breakthrough technology and a reasonable cost to realize, although it has large advantages such as the sequestration term longer than 2000 years. However CO2 can be sent to the ocean floor by shallow release, if we can use the nature that the cold CO2 to be shipped by a CO2 carrier is much denser than the ambient seawater even at shallow depths. The National Maritime Research Institute (NMRI) conducted several joint field CO2 release experiments with the Monterey Bay Aquarium Research Institute (MBARI, USA) since 1999 under the auspices of the NEDO, and proposed the improved COSMOS, CO2 Sending Method for Ocean Storage, in which CO2 is released into 200 m depth as slurry masses (mixture of dry ice and cold liquid CO2). Since 2002, under the NEDO Grant, the NMRI started a new international joint research, OACE, Ocean Abyssal Carbon Experiment with the MBARI and the University of Bergen (UoB, Norway), in order to accumulate the basic data on the long-term stability of stored CO2 and its environmental effects around storage site.

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