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Supercritical Fluids

Maobin Xie, Man Xu, Xiaomig Chen, Yi Li
Clinical applications of natural active ingredient (NAI) are limited by their instability and poor water solubility, while micronization is one strategy to overcome these drawbacks. Supercritical carbon dioxide (sc-CO2) based nano techniques have drawn great attention in nanomedicinal area for many years, due to their unique characters such as fast mass transfer, near zero surface tension and effective solvents elimination. In terms of functions of sc-CO2, many modified sc-CO2 based techniques are developed to produce NAI nanoparticles...
October 15, 2018: Mini Reviews in Medicinal Chemistry
Kateřina Plachká, František Švec, Lucie Nováková
In this study, 63 compounds measured as 10 individual mixtures containing in each case an active pharmaceutical ingredient and its relevant impurities, and additional set of 7 basic beta blockers were analyzed using ultra-high performance supercritical fluid chromatography with UV and mass spectrometry detection. The separations were accomplished using 8 different stationary phases (diol, diethylamine, 2-picolylamine, 1-aminoanthracene, BEH 2-ethylpyridine, BEH, CSH pentafluorophenyl, and HSS C18 SB), 6 modifiers (methanol, ethanol, isopropanol, methanol/acetonitrile, methanol/ethanol, ethanol/acetonitrile) and 5 additives in methanol (0...
December 18, 2018: Analytica Chimica Acta
Katarzyna Tyśkiewicz, Marcin Konkol, Edward Rój
The separation of phenolic compounds by supercritical fluid extraction has been widely studied throughout the last two decades. This is evidenced by a number of publications and articles. Supercritical fluid extraction (SFE) has become thus the effective method of separating the mentioned group of compounds. On the other hand, SFE is a beneficial approach in plant waste materials utilization and reduction of environmental burdens caused by the wastes. The aim of the study is to gather and systematize available information on the phenolic compounds separation that have been reported so far as well as to evaluate whether there is one optimal supercritical fluid extraction method for the phenolic compounds...
October 12, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Adam J E Freedman, Kyle C Peet, Jason T Boock, Kevin Penn, Kristala L J Prather, Janelle R Thompson
Supercritical carbon dioxide (scCO2 ) is an attractive substitute for conventional organic solvents due to its unique transport and thermodynamic properties, its renewability and labile nature, and its high solubility for compounds such as alcohols, ketones, and aldehydes. However, biological systems that use scCO2 are mainly limited to in vitro processes due to its strong inhibition of cell viability and growth. To solve this problem, we used a bioprospecting approach to isolate a microbial strain with the natural ability to grow while exposed to scCO2 ...
2018: Frontiers in Microbiology
Alexis Torres-Carbajal, Victor M Trejos, Luz Adriana Nicasio-Collazo
We present a systematic study of the self-diffusion coefficient for a fluid of particles interacting via the square-well pair potential by means of molecular dynamics simulations in the canonical ( N , V , T ) ensemble. The discrete nature of the interaction potential is modeled by the constant force approximation, and the self-diffusion coefficient is determined for several fluid densities at supercritical thermodynamic states. The dependence of the self-diffusion coefficient on the potential range λ is analyzed in the range of 1...
October 14, 2018: Journal of Chemical Physics
Gulay Ozkan, Paola Franco, Iolanda De Marco, Jianbo Xiao, Esra Capanoglu
Bioactivities and numerous health benefits against a number of oxidative stress related diseases have been attributed to the role of dietary antioxidants. The development of physical (spray drying, lyophilization, supercritical fluid precipitation and solvent evaporation), physico-chemical (coacervation, liposomes and ionic gelation) and chemical encapsulation techniques (interfacial polymerization and molecular inclusion complexation) enable to obtain healthier and acceptable bioactive compounds. This review focuses on the impacts of microencapsulation techniques on the encapsulation characteristics of food antioxidants...
January 30, 2019: Food Chemistry
Juan R Chamorro, Tyrel M McQueen
Ages of history are defined by the underlying materials that promoted human development: stone, bronze, and iron ages. Since the middle of the last century, humanity has lived in a silicon age, where the development of the transistor ushered in new technologies previously thought inconceivable. But as technology has advanced, so have the requirements for new materials to sustain increasing physical demands. The field of solid state chemistry is dedicated to the discovery of new materials and phenomena, and though most materials discoveries in history have been through serendipity rather than careful reaction design, the last few decades have seen an increase in the number of materials discovered through a consideration of chemical reaction kinetics and thermodynamics...
October 9, 2018: Accounts of Chemical Research
Xiaoting Li, Yan Gao, Jia Liu, Gongtian Zhang, Tianhong Zhang
Bioequivalence study is highly prized to piroxicam (PIRO), since its generic products have been widely used worldwide. The present work was undertaken to explore the pharmacokinetic behaviors and bioequivalence of two branded PIRO tablets in beagle dogs using the supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS) method. Here, a fast evaporation-free liquid-liquid extraction (EF-LLE) method using ethyl acetate was developed for extracting PIRO from beagle dog plasma. To improve the response as well as peaks elution and symmetry of analytes, several key factors were investigated including post-column compensation, stationary phase, mobile phase, column temperature, back pressure and flow rate, and finally the analytes were eluted on an ACQUITY UPC2 ™ BEH 2-EP column (100 × 3 mm, 1...
October 3, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Tae Jun Yoon, Min Young Ha, Emanuel A Lazar, Won Bo Lee, Youn-Woo Lee
The dynamics of supercritical fluids, a state of matter beyond the gas-liquid critical point, changes from diffusive to oscillatory motions at high pressure. This transition is believed to occur across a locus of thermodynamic states called the Frenkel line. The Frenkel line has been extensively investigated from the viewpoint of the dynamics, but its structural meaning is not still well understood. This letter interprets the mesoscopic picture of the Frenkel line entirely based on a topological and geometrical framework...
October 7, 2018: Journal of Physical Chemistry Letters
Qiangyuan Fan, Yongtai Zhang, Xuefeng Hou, Zhe Li, Kai Zhang, Qun Shao, Nianping Feng
The chief objective of this research was to appraise liposomes embodying a bile salt, sodium glycocholate (SGC), as oral nanoscale drug delivery system to strengthen the bioavailability of a water-soluble and weakly penetrable pharmaceutical, notoginsenoside R1 (NGR1). NGR1-loaded liposomes were prepared with the improved supercritical reverse evaporation (ISCRPE) method and the preparation conditions were optimized with response surface methodology (RSM). The mean encapsulation efficiency (EE), particle size, and polydispersity index (PDI) of the optimized liposomal formulation (NGR1@Liposomes) were 49...
October 4, 2018: International Journal of Pharmaceutics
Xiao-Fen Lin, Ranjith Kumar Kankala, Na Tang, Pei-Yao Xu, Liu-Zhi Hao, Da-Yun Yang, Shi-Bin Wang, Yu Shrike Zhang, Ai-Zheng Chen
Pulmonary delivery of drugs has attracted increasing attention in healthcare, as the lungs are an easily accessible site for noninvasive systemic delivery of drugs. Although pulmonary inhalation of porous microparticles has been shown to sustain drug delivery, there are limited reports on efficient delivery of insulin and inhalation therapy of diabetes based on supercritical carbon dioxide (SC-CO2 ) technology. Herein, this study reports the fabrication of insulin-loaded poly-l-lactide porous microspheres (INS-PLLA PMs) by using the SC-CO2 technology, and their use as an inhalation delivery system potentially for diabetes therapy...
October 3, 2018: Advanced Healthcare Materials
Petra Vaňkátová, Květa Kalíková, Anna Kubíčková
A fast and simple supercritical fluid chromatography method for the enantioseparation of twenty newly synthesized orthoconic antiferroelectric liquid crystals is reported for the first time. The effects of alkoxy spacer length and fluorine atom presence and position in the phenyl ring on chromatographic behavior were investigated. Baseline enantioseparation of all compounds was achieved using simple mobile phases consisting of carbon dioxide and alcohol as cosolvent on (3,5-dimethylphenylcarbamate) derivative of amylose as chiral stationary phase...
December 14, 2018: Analytica Chimica Acta
Ana Luiza R Pires, Liana de Azevedo Motta, Ana M A Dias, Hermínio C de Sousa, Ângela M Moraes, Mara E M Braga
This study aimed to evaluate the effect of poly(dimethylsiloxane) on the mechanical properties of chitosan-alginate (CA) polyelectrolyte complexes (PECs) with potential application as wound dressing biomaterials. For that purpose, different amounts of poly(dimethylsiloxane) were incorporated during the formulation of the PECs. Results showed that the highest tensile strength was observed when using 0.1 g of poly(dimethylsiloxane) per gram of PEC (CAS10). This formulation was also non-hemolytic, capable of inducing thrombus formation to potentially reduce bleeding, and additionally presented high stability when exposed to physiological fluids and/or conditions simulating patient bathing...
December 1, 2018: Materials Science & Engineering. C, Materials for Biological Applications
Felicity Y Han, Andrew Whittaker, Steven M Howdle, Andrew Naylor, Anjumn Shabir-Ahmed, Maree T Smith
Chronic cancer pain remains prevalent and severe for many patients, particularly in those with advanced disease. The effectiveness of analgesic/adjuvant drug treatments in routine practice has changed little in the last 30 years. To address these issues herein, we have developed sustained-release poly(lactic-co-glycolic acid) (PLGA) microparticles of hydromorphone for intrathecal injection aimed at producing prolonged periods of satisfactory analgesia in patients, as a novel strategy for alleviation of intractable cancer-related pain...
September 26, 2018: Journal of Pharmaceutical Sciences
M Thereza M S Gomes, Adina L Santana, Diego T Santos, M Angela A Meireles
BACKGROUND: The growing interest on supercritical fluids applied to particle engineering over the last years has received attention from the food and non-food industries, in terms of processing, packaging and preservation of these products. The rapid expansion of supercritical solutions (RESS) process is an efficient and promising method to produce small particles with narrow size distribution. OBJECTIVE: In this review we report technological aspects on the application of RESS process applied to the food and non-food industry, considering recent data and patent survey registered in literature...
September 25, 2018: Recent Patents on Food, Nutrition & Agriculture
Philipp Schienbein, Dominik Marx
The supercritical phase of fluids has long been known to feature significantly different liquidlike and gaslike regimes. However, it is textbook knowledge that the supercritical state is a homogeneous fluid phase where properties change continuously. Nevertheless, there has been an increasing amount of evidence published that suggests that there might exist a unique line that rigorously separates different regimes in supercritical phases, particularly in the case of water. Here, we use the quasiexact IAPWS95 equation of state to rigorously assess the macroscopic thermodynamic properties of supercritical water without invoking any water model or related approximations...
August 2018: Physical Review. E
Zhi Yang, Yan Peng, Mengna Jin, Liqin Lin
An analytical method was developed for simultaneous rapid determination of 12 anti-allergic chemical drugs in Chinese traditional patent medicine and health food by supercritical fluid chromatography tandem mass spectrometry with solid phase extraction (SPE-SFC-MS/MS). Samples were extracted with methanol by sonification and then purified by Oasis mixed-model cation exchange SPE. The extracts were separated on a Waters Trefoil CEL1 (150 mm×3.0 mm, 2.5 μ m) column with a mobile phase consisting of carbon dioxide-methanol containing 0...
September 8, 2018: Se Pu, Chinese Journal of Chromatography
Ana-Marija Cikoš, Stela Jokić, Drago Šubarić, Igor Jerković
Marine macroalgae represent a rich source of bioactive compounds that can be implemented in various food, cosmetic, and pharmaceutical products for health improvement. It has been proven that these bioactive compounds, such as polyphenols, polysaccharides, carotenoids, and ω-3 fatty acids possess bioactivity. For the extraction of these compounds, modern methods (Supercritical Fluid Extraction (SFE), Subcritical Water Extraction (SWE), Ultrasound-Assisted Extraction (UAE), and Microwave-Assisted Extraction (MAE)) have been used due to their advantages over the conventional methods...
September 23, 2018: Marine Drugs
Richard A Messerly, Michael R Shirts, Andrei F Kazakov
Molecular simulation results at extreme temperatures and pressures can supplement experimental data when developing fundamental equations of state. Since most force fields are optimized to agree with vapor-liquid equilibria (VLE) properties, however, the reliability of the molecular simulation results depends on the validity/transferability of the force field at higher temperatures and pressures. As demonstrated in this study, although state-of-the-art united-atom Mie λ -6 potentials for normal and branched alkanes provide accurate estimates for VLE, they tend to over-predict pressures for dense supercritical fluids and compressed liquids...
September 21, 2018: Journal of Chemical Physics
Jiawei Ding, Ming Zhang, Huixue Dai, Chunmian Lin
Mandelic acid and its derivatives are important chiral analogs which are widely used in the pharmaceutical synthetic industry. The present study investigated the enantiomeric separation of six mandelic acids (mandelic acid, 2-chloromandelic acid, 3-chloromandelic acid, 4-chloromandelic acid, 4-bromomandelic acid, 4-methoxymandelic acid) on the Chiralpak AD-3 column by supercritical fluid chromatography. The influences of volume fraction of trifluoroacetic acid, type and percentage of modifier, column temperature, and backpressure on the separation efficiency were investigated...
September 20, 2018: Chirality
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