stability study
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2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Justin M. Curtiss ◽  
Darren K. Emge

AbstractGeneration and control of humidity in a testing environment is crucial when evaluating a chemical vapor sensor as water vapor in the air can not only interfere with the sensor itself, but also react with a chemical analyte changing its composition. Upon constructing a split-flow humidity generator for chemical vapor sensor development, numerous issues were observed due to instability of the generated relative humidity level and drift of the humidity over time. By first fixing the initial relative humidity output of the system at 50%, we studied the effects of flowrate on stabilization time along with long term stability for extended testing events. It was found that the stabilization time can be upwards of 7 h, but can be maintained for greater than 90 h allowing for extended experiments. Once the stabilization time was known for 50% relative humidity output, additional studies at differing humidity levels and flowrates were performed to better characterize the system. At a relative humidity of 20% there was no time required to stabilize, but when increased to 80% this time increased to over 4 h. With this information we were better able to understand the generation process and characterize the humidity generation system, output stabilization and possible modifications to limit future testing issues.


Author(s):  
RASHAD M. KAOUD ◽  
EMAN J. HEIKAL ◽  
TAHA M. HAMMADY

Objective: The study's main goal is to develop a suitable niosomes (NS) encapsulated drug for anti-inflammatory effects such as diacerein (DC) and to evaluate the system's vesicle size (VS), entrapment efficiency (EE %), physical stability and in vitro release. Methods: Tween (40 and 60), cholesterol, and stearylamine were used in a 1:1:0.1 molar ratios as non-ionic surfactants. Thin film hydration was used to create the NS. Results: The higher EE% was observed with NS (F11) prepared from tween 60, cholesterol and 2.5 min sonication. These formulations' release patterns were Higuchi diffusion and first order. For the stability study, NS formulations were stored at temperature between 2-8 °C for 60 d retains the most drugs when compared to room and high temperature conditions. Conclusion: The findings of this study have conclusively shown that after NS encapsulation of DC, drug release is prolonged at a constant and controlled rate.


Author(s):  
MEGHANA RAYKAR ◽  
MALARKODI VELRAJ

Objective: This study aims to Formulate Mouth Dissolving Tablets (MDTs) of Tofacitinib Citrate with the increase in bioavailability and patient compliance. Methods: Mouth Dissolving Tablets (MDTs) of Tofacitinib Citrate were developed by full factorial design at 32levelsand prepared by direct compression method using super integrants like sodium starch glycolate, Ludiflash. The tablets were compressed into compacts on a 10 station tablet machine. The bulk drug was characterised by determining, MP, Solubility, pH and FTIR spectra. Results: The weight variation, hardness and diameter, thickness, friability, drug content, wetting time, in vitro disintegration time and in vitro dissolution studies, and stability study, tablet thickness, weight variation and drug content post compression parameters remained consistent and reproducible. All the formulations showed, almost 100 percent of drug release within 75 min. Formulations F1, F2 and F3 were prepared with 5 mg of SSG and 20 mg, 30 mg, and 40 mg Ludiflash which shows % release of drug in the order of F1<F2<F3. Formulations F4, F5 and F6 were prepared with 10 mg of SSG and 20 mg, 30 mg, and 40 mg Ludiflash which shows % release of drug in the order of F4<F5<F6. Formulations F7, F8 and F9 were prepared with 15 mg of SSG and 20 mg, 30 mg, and 40 mg Ludiflash which shows % release of drug in the order of F7<F8<F9. Conclusion: It is concluded that the amount of superdisintegrants decreases disintegration time of tablets, decreases wetting time, increases the cumulative % drug release causes better absorption.


AIP Advances ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 015319
Author(s):  
Hasnet Ahmed ◽  
Payman Rajai ◽  
Mohammed Jalal Ahamed

2022 ◽  
Vol 17 (01) ◽  
pp. C01051
Author(s):  
R.M.I.D. Gamage ◽  
S. Basnet ◽  
E. Cortina Gil ◽  
P. Demin ◽  
A. Giammanco ◽  
...  

Abstract Muon tomography or “muography” is an emerging imaging technique that uses cosmogenic muons as the radiation source. Due to its diverse range of applications and the use of natural radiation, muography is being applied across many fields such as geology, archaeology, civil engineering, nuclear reactor monitoring, nuclear waste characterization, underground surveys, etc. Muons can be detected using various detector technologies, among which, resistive plate chambers (RPC) are a very cost effective choice. RPCs are planar detectors which use ionization in a thin gas gap to detect cosmic muons, already used since years in major particle accelerator experiments. We have developed a muon telescope (or “muoscope”) composed of small scale RPCs. The design goal for our muoscope is to be portable and autonomous, in order to take data in places that are not easily accessible. The whole setup is light and compact, such to be easily packed in a car trunk. Individual RPCs are hosted in gas-tight aluminium cases. There is no need for gas bottles, once the chambers are filled. The muoscope can be controlled from a reasonable distance using wireless connection. In this paper we summarize the guiding principles of our project and present some recent developments and future prospects, including a long-term stability study of the resistivity of the semiconductive coating obtained with serigraphy.


2021 ◽  
pp. 548-562
Author(s):  
Muchtaridi Muchtaridi ◽  
Rini Yulianita ◽  
Iyan Sopyan ◽  
Amirah Mohd Gazzali

Drug stability is one of the most important criteria for producing safe, excellent and effective products. Some environmental factors that influence drug stability are light, temperature, and humidity. Simvastatin is a cholesterol-lowering drug that is known to be sensitive to high temperature and humidity. The purpose of this study is to analyze the effect of 6 months of real-time storage conditions on the stability of generic simvastatin tablets in public pharmacy facilities. This study used simulation method with 4 brands of simvastatin generic tablets with two different strengths (10 mg and 20 mg). In the process, the sample was conditioned in 6 different regions for 6 months. The results of temperature and humidity monitoring showed 2 locations at ≤ 25 ° C, 4 locations had a temperature of ≥ 25 °C and all locations had humidity > 65 %. The drug was evaluated for physical and chemical quality parameters at months 0, 3, and 6. After being stored for 6 months, the tablets showed a decrease in disintegration time and an increase in the friability, showing lack of durability. Similarly, there was a decrease in the content concentration in the tablets but fortunately the level was still within the accepted specification range (90 – 110 %). However, there was one tablet that did not meet the dissolution test requirements after the storage duration (Q ≤ 75 % at 30 minutes). The results of the stress test showed that simvastatin degraded in all conditions. This stress test confirmed the extreme instability of simvastatin.  Poor storage conditions can reduce the quality of generic simvastatin tablets, thus a well-controlled environment is vital in pharmacy facilities.


Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 258
Author(s):  
Daniele Bosich ◽  
Giovanni Giadrossi ◽  
Stefano Pastore ◽  
Giorgio Sulligoi

In shipboard DC grids, tightly controlled load converters can impair the system stability, thus provoking the ship blackout. Conversely, load converters regulated by low control bandwidths are capable of inducing a stabilizing action. This compensation is verifiable if the loads are few. On the contrary, the balancing of control dynamics is hardly evaluated if the bus feeds multiple (i.e., hundreds or more) DC controlled loads. In this paper, the weighted bandwidth method (WBM) is presented to assess the small-signal stability of a complex shipboard power system by aggregating the multiple converters into two sets of controlled loads. Once the validity of the aggregation is proven, a stability study is performed on the two-loads system. As the last system is more inclined to instability than the initial multiple-loads system, the verification of the two-loads stability criterion guarantees that the shipboard DC grid also remains stable. Finally, emulations on HIL verify the proposed stability assessment thus providing the first unique verification of WBM.


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