scholarly journals Predicting Deliquescence Relative Humidities of Crystals and Crystal Mixtures

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3176
Author(s):  
Heiner Veith ◽  
Christian Luebbert ◽  
Gabriele Sadowski
Keyword(s):  
Relative Humidity ◽  
Food Industry ◽  
Hydrate Formation ◽  
Aqueous Solubility ◽  
Artificial Sweeteners ◽  
Temperature Influence ◽  
Statistical Associating Fluid Theory ◽  
Fluid Theory ◽  
The Stability ◽  
Formation Of Hydrates

The presence of water in the form of relative humidity (RH) may lead to deliquescence of crystalline components above a certain RH, the deliquescence RH (DRH). Knowing the DRH values is essential, e.g., for the agrochemical industry, food industry, and pharmaceutical industry to identify stability windows for their crystalline products. This work applies the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) to purely predict the DRH of single components (organic acids, sugars, artificial sweeteners, and amides) and multicomponent crystal mixtures thereof only based on aqueous solubility data of the pure components. The predicted DRH values very well agree with the experimental ones. In addition, the temperature influence on the DRH value could be successfully predicted with PC-SAFT. The DRH prediction also differentiates between formation of hydrates and anhydrates. PC-SAFT-predicted phase diagrams of hydrate-forming components illustrate the influence of additional components on the hydrate formation as a function of RH. The DRH prediction via PC-SAFT allows for the determining of the stability of crystals and crystal mixtures without the need for time-consuming experiments.

Hydrates on the subsea wellhead in deepwater wells: Study on the growth mechanisms, impacts on drilling safety, and possible solutions

2018 ◽  
Vol 6 (4) ◽  
pp. T1081-T1093
Author(s):  
Bailing Zhang ◽  
Jin Yang ◽  
Ali Takbiri-Borujeni ◽  
Ting Sun ◽  
Ali Reza Edrisi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tilt Angle ◽  
Hydrate Formation ◽  
Deepwater Drilling ◽  
Gas Source ◽  
Blowout Preventer ◽  
Drilling Operations ◽  
Control Failure ◽  
The Stability ◽  
Formation Of Hydrates

Hydrate formation poses a risk to deepwater drilling operations. Most current studies on the hydrate formation and its impact on deepwater drilling operations have focused on the risk associated with hydrates inside the wellbore. Few researchers have studied the risk of hydrate formation outside the wellbore, and the risks to deepwater drilling are still unclear. In the South China Sea, there have been several events of hydrate growth on the outer surfaces of the subsea wellhead. The mechanisms of hydrate growth on the outer surface of the subsea wellhead are analyzed, and the gas source is predicted by analyzing the logging data of the adjacent wells. A model for the wellhead stability is developed, and the impacts of hydrate formation on the stability of the subsea wellhead are analyzed. The gas source, temperature, pressure, solid surface roughness, and relative static subsea environment are found to be the key factors in the formation of hydrate in the marine environment. The risk of hydrate formation to wellhead stability is subtle, but to blowout preventer (BOP) could be significant. Hydrates may cause BOP control failure in which the BOP could not be closed in the event of emergency; hydrate formation between the BOP and the wellhead may cause BOP not to be separated from the bottom of the wellhead. A tool was designed for controlling the formation of hydrates, with particular tilt angle and surface roughness. Because the appropriate tilt angle can divert the gas bubbles to avoid the hydrate formations at the wellhead. The designed hydrate control tool successfully mitigates the risks to drilling operations.

scholarly journals Stability of Pharmaceutical Co-Crystals at Humid Conditions Can Be Predicted

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 433
Author(s):  
Heiner Veith ◽  
Maximilian Zaeh ◽  
Christian Luebbert ◽  
Naír Rodríguez-Hornedo ◽  
Gabriele Sadowski
Keyword(s):  
Pharmaceutical Formulations ◽  
Active Pharmaceutical Ingredient ◽  
Storage Conditions ◽  
Pharmaceutical Products ◽  
Active Pharmaceutical Ingredients ◽  
Statistical Associating Fluid Theory ◽  
Pharmaceutical Ingredients ◽  
Soluble Solid ◽  
Fluid Theory ◽  
The Stability

Knowledge of the stability of pharmaceutical formulations against relative humidity (RH) is essential if they are to become pharmaceutical products. The increasing interest in formulating active pharmaceutical ingredients as stable co-crystals (CCs) triggers the need for fast and reliable in-silico predictions of CC stability as a function of RH. CC storage at elevated RH can lead to deliquescence, which leads to CC dissolution and possible transformation to less soluble solid-state forms. In this work, the deliquescence RHs of the CCs succinic acid/nicotinamide, carbamazepine/nicotinamide, theophylline/citric acid, and urea/glutaric acid were predicted using the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT). These deliquescence RH values together with predicted phase diagrams of CCs in water were used to determine critical storage conditions, that could lead to CC instability, that is, CC dissolution and precipitation of its components. The importance of CC phase purity on RH conditions for CC stability is demonstrated, where trace levels of a separate phase of active pharmaceutical ingredient or of coformer can significantly decrease the deliquescence RH. The use of additional excipients such as fructose or xylitol was predicted to decrease the deliquescence RH even further. All predictions were successfully validated by stability measurements at 58%, 76%, 86%, 93%, and 98% RH and 25 °C.

Insights into Potent Therapeutical Antileukemic Agent L-glutaminase Enzyme Under Solid-state Fermentation: A Review

2020 ◽  
Vol 21 (3) ◽  
pp. 211-220 ◽  
Author(s):  
Chandrasai Potla Durthi ◽  
Madhuri Pola ◽  
Satish Babu Rajulapati ◽  
Anand Kishore Kola
Keyword(s):  
Solid State ◽  
Solid State Fermentation ◽  
Food Industry ◽  
Energy Requirement ◽  
Production Studies ◽  
Wide Range ◽  
Hybridoma Technology ◽  
Bacteria And Fungi ◽  
The Stability ◽  
Glutaminase Activity

Aim & objective: To review the applications and production studies of reported antileukemic drug L-glutaminase under Solid-state Fermentation (SSF). Overview: An amidohydrolase that gained economic importance because of its wide range of applications in the pharmaceutical industry, as well as the food industry, is L-glutaminase. The medical applications utilized it as an anti-tumor agent as well as an antiretroviral agent. L-glutaminase is employed in the food industry as an acrylamide degradation agent, as a flavor enhancer and for the synthesis of theanine. Another application includes its use in hybridoma technology as a biosensing agent. Because of its diverse applications, scientists are now focusing on enhancing the production and optimization of L-glutaminase from various sources by both Solid-state Fermentation (SSF) and submerged fermentation studies. Of both types of fermentation processes, SSF has gained importance because of its minimal cost and energy requirement. L-glutaminase can be produced by SSF from both bacteria and fungi. Single-factor studies, as well as multi-level optimization studies, were employed to enhance L-glutaminase production. It was concluded that L-glutaminase activity achieved by SSF was 1690 U/g using wheat bran and Bengal gram husk by applying feed-forward artificial neural network and genetic algorithm. The highest L-glutaminase activity achieved under SSF was 3300 U/gds from Bacillus sp., by mixture design. Purification and kinetics studies were also reported to find the molecular weight as well as the stability of L-glutaminase. Conclusion: The current review is focused on the production of L-glutaminase by SSF from both bacteria and fungi. It was concluded from reported literature that optimization studies enhanced L-glutaminase production. Researchers have also confirmed antileukemic and anti-tumor properties of the purified L-glutaminase on various cell lines.

scholarly journals Anthocyanins Recovered from Agri-Food By-Products Using Innovative Processes: Trends, Challenges, and Perspectives for Their Application in Food Systems

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2632
Author(s):  
Henrique Silvano Arruda ◽  
Eric Keven Silva ◽  
Nayara Macêdo Peixoto Araujo ◽  
Gustavo Araujo Pereira ◽  
Glaucia Maria Pastore ◽  
...  
Keyword(s):  
Food Systems ◽  
Food Industry ◽  
Biological Properties ◽  
Extraction Techniques ◽  
Naturally Occurring ◽  
Current Review ◽  
Natural Colorants ◽  
Conventional Extraction ◽  
The Stability ◽  
By Products

Anthocyanins are naturally occurring phytochemicals that have attracted growing interest from consumers and the food industry due to their multiple biological properties and technological applications. Nevertheless, conventional extraction techniques based on thermal technologies can compromise both the recovery and stability of anthocyanins, reducing their global yield and/or limiting their application in food systems. The current review provides an overview of the main innovative processes (e.g., pulsed electric field, microwave, and ultrasound) used to recover anthocyanins from agri-food waste/by-products and the mechanisms involved in anthocyanin extraction and their impacts on the stability of these compounds. Moreover, trends and perspectives of anthocyanins’ applications in food systems, such as antioxidants, natural colorants, preservatives, and active and smart packaging components, are addressed. Challenges behind anthocyanin implementation in food systems are displayed and potential solutions to overcome these drawbacks are proposed.

Wax precipitation modelling using Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT)

2021 ◽  
Vol 531 ◽  
pp. 112911
Author(s):  
I. Shahsenov ◽  
I. Baghishov ◽  
P. Allahverdiyev ◽  
E. Azizov
Keyword(s):  
Statistical Associating Fluid Theory ◽  
Wax Precipitation ◽  
Fluid Theory
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