scholarly journals Tuning the spontaneous formation kinetics of caffeine : malonic acid co-crystals

CrystEngComm ◽  
2016 ◽  
Vol 18 (15) ◽  
pp. 2617-2620 ◽  
Author(s):  
K. P. Nartowski ◽  
Y. Z. Khimyak ◽  
D. J. Berry
Keyword(s):  
Malonic Acid ◽  
Crystal System ◽  
Spontaneous Formation ◽  
Formation Kinetics ◽  
And Control ◽  
Kinetics Of

It has previously been reported that the caffeine : malonic acid co-crystal system forms spontaneously upon the contact of the two materials, here we explore the mechanism of this formation and control the kinetics to enable us to monitor the conversion.

Investigation of irradiation-induced nucleation processes in silicon and germanium

1995 ◽  
Vol 53 ◽  
pp. 224-225
Author(s):  
Harry A. Atwater ◽  
C.M. Yang ◽  
K.V. Shcheglov
Keyword(s):  
Room Temperature ◽  
Crystal Size ◽  
Initial Distribution ◽  
Engineering Control ◽  
Size Evolution ◽  
Silicon And Germanium ◽  
Ge Quantum Dot ◽  
And Control ◽  
Germanium Quantum Dots ◽  
Kinetics Of

Studies of the initial stages of nucleation of silicon and germanium have yielded insights that point the way to achievement of engineering control over crystal size evolution at the nanometer scale. In addition to their importance in understanding fundamental issues in nucleation, these studies are relevant to efforts to (i) control the size distributions of silicon and germanium “quantum dots𠇍, which will in turn enable control of the optical properties of these materials, (ii) and control the kinetics of crystallization of amorphous silicon and germanium films on amorphous insulating substrates so as to, e.g., produce crystalline grains of essentially arbitrary size.Ge quantum dot nanocrystals with average sizes between 2 nm and 9 nm were formed by room temperature ion implantation into SiO2, followed by precipitation during thermal anneals at temperatures between 30°C and 1200°C[1]. Surprisingly, it was found that Ge nanocrystal nucleation occurs at room temperature as shown in Fig. 1, and that subsequent microstructural evolution occurred via coarsening of the initial distribution.

scholarly journals Structure and Formation Kinetics of Millimeter‐Size Single Domain Supercrystals

2021 ◽  
pp. 2101869
Author(s):  
Daniel García‐Lojo ◽  
Evgeny Modin ◽  
Sergio Gómez‐Graña ◽  
Marianne Impéror‐Clerc ◽  
Andrey Chuvilin ◽  
...  
Keyword(s):  
Single Domain ◽  
Formation Kinetics ◽  
Kinetics Of

Understanding the phase formation kinetics of nano-crystalline kesterite deposited on mesoscopic scaffolds via in situ multi-wavelength Raman-monitored annealing

2016 ◽  
Vol 18 (42) ◽  
pp. 29435-29446 ◽  
Author(s):  
Zhuoran Wang ◽  
Samir Elouatik ◽  
George P. Demopoulos
Keyword(s):  
Real Time ◽  
Phase Formation ◽  
Formation Kinetics ◽  
Nano Crystalline ◽  
Multi Wavelength ◽  
Real Time Information ◽  
Kinetics Of ◽  
Time Information ◽  
Annealing Method

The in situ Raman monitored annealing method is developed in this work to provide real-time information on phase formation and crystallinity evolution of kesterite deposited on a TiO2 mesoscopic scaffold.

scholarly journals Insights into the Control of Drug Release from Complex Immediate Release Formulations

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 933
Author(s):  
Runqiao Dong ◽  
James C. DiNunzio ◽  
Brian P. Regler ◽  
Walter Wasylaschuk ◽  
Adam Socia ◽  
...  
Keyword(s):  
Drug Release ◽  
Immediate Release ◽  
Liquid Penetration ◽  
Central Importance ◽  
Water Penetration ◽  
Release Process ◽  
Terahertz Pulsed Imaging ◽  
And Control ◽  
Kinetics Of ◽  
Spray Dried

The kinetics of water transport into tablets, and how it can be controlled by the formulation as well as the tablet microstructure, are of central importance in order to design and control the dissolution and drug release process, especially for immediate release tablets. This research employed terahertz pulsed imaging to measure the process of water penetrating through tablets using a flow cell. Tablets were prepared over a range of porosity between 10% to 20%. The formulations consist of two drugs (MK-8408: ruzasvir as a spray dried intermediate, and MK-3682: uprifosbuvir as a crystalline drug substance) and NaCl (0% to 20%) at varying levels of concentrations as well as other excipients. A power-law model is found to fit the liquid penetration exceptionally well (average R2>0.995). For each formulation, the rate of water penetration, extent of swelling and the USP dissolution rate were compared. A factorial analysis then revealed that the tablet porosity was the dominating factor for both liquid penetration and dissolution. NaCl more significantly influenced liquid penetration due to osmotic driving force as well as gelling suppression, but there appears to be little difference when NaCl loading in the formulation increases from 5% to 10%. The level of spray dried intermediate was observed to further limit the release of API in dissolution.

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