The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jianfeng Chen - One of the best experts on this subject based on the ideXlab platform.
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a green route to beclomethasone dipropionate nanoparticles via Solvent anti Solvent Precipitation by using subcritical water as the Solvent
Powder Technology, 2017Co-Authors: Dan Wang, Jiexin Wang, Neil R Foster, Jianfeng ChenAbstract:Abstract Oral beclomethasone dipropionate (BDP) has been extensively studied in the management of ulcerative colitis in clinical practice in recently years. However, the effective bioavailability and absorption of BDP are limited by its poor water solubility when administered orally. Herein, we report a green process for the synthesis of BDP nanoparticles via Solvent anti-Solvent Precipitation, in which the subcritical water (SBCW) and cold water were used as the Solvent and anti-Solvent respectively. Polyethylene glycol (PEG), a non-ionic, hydrophilic polymer was introduced as stabilizers in the SBCW process to obtain sub-50 nm BDP nanoparticles with improved dissolution rate. Scanning electronic microscopy (SEM), Fourier transform infrared (FTIR) spectrophotometry, powder X-ray diffraction (XRD) and dissolution tests were performed to investigate the corresponding particle morphology, structure and dissolution rate properties of the BDP nanoparticles. The obtained BDP nanoparticles are
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ultrafine clarithromycin nanoparticles via anti Solvent Precipitation in subcritical water effect of operating parameters
Powder Technology, 2017Co-Authors: Xiaofei Wen, Dan Wang, Neil R Foster, Jianfeng ChenAbstract:Abstract Clarithromycin (CLA) is an important drug used to treat various bacterial infections, while its effective bioavailability is limited by the poor water-solubility of the CLA molecule. Subcritical water (SBCW) processes have been demonstrated to be a new promising alternative for the preparation of drug nanoparticles with enhanced dissolution rate. In this work, we reported ultrafine CLA nanoparticles via anti-Solvent Precipitation in subcritical water, with detailed studies on the effects of operating parameters. The corresponding particle morphology, and dissolution rate properties of the CLA nanoparticles were characterized through scanning electronic microscopy (SEM), Fourier transform infrared spectrophotometry (FT-IR), powder X-ray diffraction (XRD) and dissolution tests. Under optimized experimental conditions, which was using 1.5 mL of SBCW at 150 °C as the Solvent and 15 of aqueous PVP solution (0.4 wt%) as the anti-Solvent, uniform sub-50 nm sized CLA nanoparticles are obtained. According to the dissolution testing, the ultrafine CLA nanoparticles exhibit very high dissolution rate (over 85% at 60 min) compared with that of raw CLA (10% at 60 min). Our results suggest that as-synthesized ultrafine CLA nanoparticles via anti-Solvent Precipitation in subcritical water are promising for efficient therapy.
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facile preparation of danazol nanoparticles by high gravity anti Solvent Precipitation hgap method
Chinese Journal of Chemical Engineering, 2009Co-Authors: Hong Zhao, Jiexin Wang, Haixia Zhang, Zhigang Shen, Jimmy Yun, Jianfeng ChenAbstract:The nanoparticles of the hydrophobic drug of danazol with narrow size distribution are facilely prepared by controlled high-gravity anti-Solvent Precipitation (HGAP) process. Intensified micromixing and uniform nucleation environment are created by the high-gravity equipment (rotating packed bed) in carrying out the anti-Solvent Precipitation process to produce nanoparticles. The average particle size decreases from 55μm of the raw danazol to190nm of the nanoparticles. The Brunauer-Emmett-Teller (BET) surface area sharply increases from 0.66m^2•g^(-1) to 15.08 m^2g^(-1). Accordingly， the dissolution rate is greatly improved. The molecular state, chemical composition, and crystal form of the danazol nanoparticles remains unchanged after processing according to Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The high recovery ratio and continuous production capacity are highly appreciated in industry. Therefore, the HOAP method might offer a general and facile platforrI1 for mass production of hydrophobic pharmaceutical danazol particles in nanometer range.
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preparation and characterization of uniform nanosized cephradine by combination of reactive Precipitation and liquid anti Solvent Precipitation under high gravity environment
International Journal of Pharmaceutics, 2005Co-Authors: Jie Zhong, Zhigang Shen, Yan Yang, Jianfeng ChenAbstract:In this work, a novel direct method, which was combined with reactive Precipitation and liquid anti-Solvent Precipitation under high gravity environment, had been developed to prepare nanosized cephradine with narrow particle size distribution. Compared with commercial crude cephradine, the prepared cephradine showed a significant decrease in particle size, a significant increase in the specific surface area and shorter dissolving time when used for injection. The characteristic particle size was between 200-400 nm. The specific surface area increased from 2.95 to 10.87 m2/g after micronization. When the amount of L-arginin decreased from 0.25 to 0.18 g, the mixture of nanosized cephradine and L-arginine could still dissolve in 1 min. The X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) analysis indicated that the physical characteristics and molecular states remained unchanged after the recrystallization process. This method had potential application in industrial fields because of its low cost, efficient processing and the ease of scaling-up.
Guangguo Ying - One of the best experts on this subject based on the ideXlab platform.
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determination of 24 personal care products in fish bile using hybrid Solvent Precipitation and dispersive solid phase extraction cleanup with ultrahigh performance liquid chromatography tandem mass spectrometry and gas chromatography mass spectrometr
Journal of Chromatography A, 2018Co-Authors: Li Yao, Lijuan Zhang, Wangrong Liu, Jianliang Zhao, Yousheng Liu, Qianqian Zhang, Guangguo YingAbstract:Abstract Personal care products (PCPs) are ubiquitous in aquatic environments owing to the continuous discharge of domestic wastewater from highly urbanized regions. These PCPs can be adsorbed by fish and thereafter usually enter the bile of the fish through biliary excretion. In this study, a sensitive method based on a combination of hybrid Solvent Precipitation and dispersive solid phase extraction (d-SPE) purification was developed to simultaneously extract and detect 24 PCPs, namely, 16 biocides, 4 synthetic musks, and 4 benzotriazoles, from fish bile. Hybrid Precipitation on solid phase extraction (SPE) tubes was applied to remove phospholipids and proteins, and a d-SPE procedure was used for further purification. The extraction Solvents for the hybrid Precipitation/SPE tubes and d-SPE materials were optimized. The method performance for bile samples both with and without enzyme hydrolysis using β-glucuronidase/aryl-sulfatase were validated. The 24 PCPs in fish bile were spiked with standard concentrations of 10 ng/mL, 20 ng/mL, 100 ng/mL, and 200 ng/mL to evaluate recoveries, which ranged from 70 to 120% for 16, 16, 22, and 21 analytes with hydrolysis, respectively, and 70–120% for 14, 15, 23, and 23 analytes without hydrolysis, respectively. The quantification limits for target PCPs were in the range 0.26–7.38 ng/mL [excluding musk xylene (MX) and musk ketone (MK)] and 0.20–9.48 ng/mL (excluding MX and MK) for bile samples with and without enzyme hydrolysis, respectively. After enzyme hydrolysis, 12 PCPs were detected in bile from fish collected from the Yangtze River, with a maximum detected concentration of 460 ng/mL, for triclosan (TCS). The hydrolysis reaction indicated that high percentages of glucuronide and sulfate metabolites for some PCPs, i.e. four parabens and TCS, existed in the bile.
Li Yao - One of the best experts on this subject based on the ideXlab platform.
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determination of 24 personal care products in fish bile using hybrid Solvent Precipitation and dispersive solid phase extraction cleanup with ultrahigh performance liquid chromatography tandem mass spectrometry and gas chromatography mass spectrometr
Journal of Chromatography A, 2018Co-Authors: Li Yao, Lijuan Zhang, Wangrong Liu, Jianliang Zhao, Yousheng Liu, Qianqian Zhang, Guangguo YingAbstract:Abstract Personal care products (PCPs) are ubiquitous in aquatic environments owing to the continuous discharge of domestic wastewater from highly urbanized regions. These PCPs can be adsorbed by fish and thereafter usually enter the bile of the fish through biliary excretion. In this study, a sensitive method based on a combination of hybrid Solvent Precipitation and dispersive solid phase extraction (d-SPE) purification was developed to simultaneously extract and detect 24 PCPs, namely, 16 biocides, 4 synthetic musks, and 4 benzotriazoles, from fish bile. Hybrid Precipitation on solid phase extraction (SPE) tubes was applied to remove phospholipids and proteins, and a d-SPE procedure was used for further purification. The extraction Solvents for the hybrid Precipitation/SPE tubes and d-SPE materials were optimized. The method performance for bile samples both with and without enzyme hydrolysis using β-glucuronidase/aryl-sulfatase were validated. The 24 PCPs in fish bile were spiked with standard concentrations of 10 ng/mL, 20 ng/mL, 100 ng/mL, and 200 ng/mL to evaluate recoveries, which ranged from 70 to 120% for 16, 16, 22, and 21 analytes with hydrolysis, respectively, and 70–120% for 14, 15, 23, and 23 analytes without hydrolysis, respectively. The quantification limits for target PCPs were in the range 0.26–7.38 ng/mL [excluding musk xylene (MX) and musk ketone (MK)] and 0.20–9.48 ng/mL (excluding MX and MK) for bile samples with and without enzyme hydrolysis, respectively. After enzyme hydrolysis, 12 PCPs were detected in bile from fish collected from the Yangtze River, with a maximum detected concentration of 460 ng/mL, for triclosan (TCS). The hydrolysis reaction indicated that high percentages of glucuronide and sulfate metabolites for some PCPs, i.e. four parabens and TCS, existed in the bile.
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Determination of 24 personal care products in fish bile using hybrid Solvent Precipitation and dispersive solid phase extraction cleanup with ultrahigh performance liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometr
'Elsevier BV', 2018Co-Authors: Li Yao, Lv Yin-zhi, Zhang Li-juan, Liu Wang-rong, Zhao Jian-liang, Liu You-sheng, Zhang Qian-qian, Ying Guang-guoAbstract:Personal care products (PCPs) are ubiquitous in aquatic environments owing to the continuous discharge of domestic wastewater from highly urbanized regions. These PCPs can be adsorbed by fish and thereafter usually enter the bile of the fish through biliary excretion. In this study, a sensitive method based on a combination of hybrid Solvent Precipitation and dispersive solid phase extraction (d-SPE) purification was developed to simultaneously extract and detect 24 PCPs, namely, 16 biocides, 4 synthetic musks, and 4 benzotriazoles, from fish bile. Hybrid Precipitation on solid phase extraction (SPE) tubes was applied to remove phospholipids and proteins, and a d-SPE procedure was used for further purification. The extraction Solvents for the hybrid Precipitation/SPE tubes and d-SPE materials were optimized. The method performance for bile samples both with and without enzyme hydrolysis using beta-glucuronidase/arylsulfatase were validated. The 24 PCPs in fish bile were spiked with standard concentrations of 10 ng/mL, 20 ng/mL, 100 ng/mL, and 200 ng/mL to evaluate recoveries, which ranged from 70 to 120% for 16, 16, 22, and 21 analytes with hydrolysis, respectively, and 70-120% for 14,15, 23, and 23 analytes without hydrolysis, respectively. The quantification limits for target PCPs were in the range 0.26-7.38 ng/mL [excluding musk xylene (MX) and musk ketone (MK)] and 0.20-9.48 ng/mL (excluding MX and MK) for bile samples with and without enzyme hydrolysis, respectively. After enzyme hydrolysis, 12 PCPs were detected in bile from fish collected from the Yangtze River, with a maximum detected concentration of 460 ng/mL, for triclosan (TCS). The hydrolysis reaction indicated that high percentages of glucuronide and sulfate metabolites for some PCPs, i.e. four parabens and TCS, existed in the bile. (C) 2018 Elsevier B.V. All rights reserved
Neil R Foster - One of the best experts on this subject based on the ideXlab platform.
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a green route to beclomethasone dipropionate nanoparticles via Solvent anti Solvent Precipitation by using subcritical water as the Solvent
Powder Technology, 2017Co-Authors: Dan Wang, Jiexin Wang, Neil R Foster, Jianfeng ChenAbstract:Abstract Oral beclomethasone dipropionate (BDP) has been extensively studied in the management of ulcerative colitis in clinical practice in recently years. However, the effective bioavailability and absorption of BDP are limited by its poor water solubility when administered orally. Herein, we report a green process for the synthesis of BDP nanoparticles via Solvent anti-Solvent Precipitation, in which the subcritical water (SBCW) and cold water were used as the Solvent and anti-Solvent respectively. Polyethylene glycol (PEG), a non-ionic, hydrophilic polymer was introduced as stabilizers in the SBCW process to obtain sub-50 nm BDP nanoparticles with improved dissolution rate. Scanning electronic microscopy (SEM), Fourier transform infrared (FTIR) spectrophotometry, powder X-ray diffraction (XRD) and dissolution tests were performed to investigate the corresponding particle morphology, structure and dissolution rate properties of the BDP nanoparticles. The obtained BDP nanoparticles are
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ultrafine clarithromycin nanoparticles via anti Solvent Precipitation in subcritical water effect of operating parameters
Powder Technology, 2017Co-Authors: Xiaofei Wen, Dan Wang, Neil R Foster, Jianfeng ChenAbstract:Abstract Clarithromycin (CLA) is an important drug used to treat various bacterial infections, while its effective bioavailability is limited by the poor water-solubility of the CLA molecule. Subcritical water (SBCW) processes have been demonstrated to be a new promising alternative for the preparation of drug nanoparticles with enhanced dissolution rate. In this work, we reported ultrafine CLA nanoparticles via anti-Solvent Precipitation in subcritical water, with detailed studies on the effects of operating parameters. The corresponding particle morphology, and dissolution rate properties of the CLA nanoparticles were characterized through scanning electronic microscopy (SEM), Fourier transform infrared spectrophotometry (FT-IR), powder X-ray diffraction (XRD) and dissolution tests. Under optimized experimental conditions, which was using 1.5 mL of SBCW at 150 °C as the Solvent and 15 of aqueous PVP solution (0.4 wt%) as the anti-Solvent, uniform sub-50 nm sized CLA nanoparticles are obtained. According to the dissolution testing, the ultrafine CLA nanoparticles exhibit very high dissolution rate (over 85% at 60 min) compared with that of raw CLA (10% at 60 min). Our results suggest that as-synthesized ultrafine CLA nanoparticles via anti-Solvent Precipitation in subcritical water are promising for efficient therapy.
Simon A Kondrat - One of the best experts on this subject based on the ideXlab platform.
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preparation of a highly active ternary cu zn al oxide methanol synthesis catalyst by supercritical co2 anti Solvent Precipitation
Catalysis Today, 2018Co-Authors: Simon A Kondrat, Stuart Hamilton Taylor, Jonathan K Bartley, Paul J Smith, Michael S Spencer, Gordon Kelly, Colin William Park, Christopher J KielyAbstract:Methanol synthesis using Cu/ZnO/Al2O3 catalysts is a well-established industrial process. Catalyst development is always an important factor and this has resulted in the current fully optimised commercial catalyst that is prepared by co-Precipitation via hydroxycarbonate precursors. Recently, the synthesis of a CuZn hydroxycarbonate precursor, analogous to the rare mineral georgeite, was reported to produce a high activity methanol synthesis catalyst. Here we report the addition of Al3+, the third component found in industrial catalysts, to the zincian georgeite-derived catalyst prepared using a supercritical CO2 anti-Solvent Precipitation methodology. The co-addition of an AlO(OH) sol to the Cu/Zn precursor solution was found to not disrupt the formation of the CuZn georgeite phase, while providing efficient mixing of the Al3+ within the material. The catalyst derived from the CuZn georgeite precursor phase doped with Al3+ showed a high level of methanol synthesis productivity, which was comparable to that of the binary CuZn georgeite derived catalyst. This material also exhibited enhanced stability during an accelerated ageing test compared to the non-Al doped zincian georgeite material. Performance was benchmarked against an industrially relevant Cu/ZnO/Al2O3 standard catalyst.
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novel cobalt zinc oxide fischer tropsch catalysts synthesised using supercritical anti Solvent Precipitation
Catalysis Science & Technology, 2014Co-Authors: Raimon P Marin, Simon A Kondrat, Thomas E Davies, David J Morgan, Dan I Enache, Gary Bevan Combes, Stuart Hamilton Taylor, Jonathan K Bartley, Graham J HutchingsAbstract:Cobalt zinc oxide catalysts have been prepared by anti-Solvent Precipitation in supercritical CO2 and investigated for CO hydrogenation. Here we show how the textural and catalytic properties of the catalyst can be tailored by the addition of water to the initial solution of cobalt and zinc acetates in methanol. Characterization of the catalysts by powder X-ray diffraction, infra-red and Raman spectroscopy showed that in the absence of water a high surface area mixed acetate was produced which upon calcination formed wurtzite type Zn1−xCoxO and spinel type ZnxCo3−xO4. The addition of 5 vol.% water resulted in a phase separated Co3O4/ZnO catalyst and enhanced active cobalt surface area as a result of disruption of the Solvent/CO2 phase equilibrium during Precipitation.
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green preparation of transition metal oxide catalysts using supercritical co2 anti Solvent Precipitation for the total oxidation of propane
Applied Catalysis B-environmental, 2013Co-Authors: Raimon P Marin, Simon A Kondrat, Thomas E Davies, Jonathan K Bartley, Graham J Hutchings, Rebecca K Pinnell, Stanislaw E Golunski, Stuart Hamilton TaylorAbstract:A series of metal oxide catalysts, including Fe3O4, NiO, CuO and Co3O4, have been prepared by supercritical anti-Solvent Precipitation and evaluated for the total oxidation of propane. Co3O4 was found to be the most active catalyst and our studies have focussed on this oxide. The addition of water as co-Solvent in the supercritical anti-Solvent preparation was investigated. Powder X-ray diffraction and infrared spectroscopy indicated that the addition of water promoted the formation of carbonate species in the catalyst precursors. The formation of the catalysts from the precursor were optimised by investigating the thermal treatment conditions, by studying variables including time, temperature and atmosphere. The optimal conditions for catalyst preparation required precursor Precipitation containing 10 vol% water co-Solvent followed by a 2 h calcination at 250 °C. These conditions produced Co3O4 with high surface areas (>100 m2 g−1), which were very active catalysts producing 50% propane conversion at 175 °C.
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synthesis of high surface area cumn2o4 by supercritical anti Solvent Precipitation for the oxidation of co at ambient temperature
Catalysis Science & Technology, 2011Co-Authors: Zirong Tang, Simon A Kondrat, Thomas E Davies, Stuart Hamilton Taylor, Jonathan K Bartley, Calum Dickinson, Albert Frederick Carley, Mathieu Allix, Matthew J Rosseinsky, John B ClaridgeAbstract:A series of high surface area nanocrystalline copper manganese oxide catalysts have been prepared by supercritical anti-Solvent (SAS) Precipitation using CO2 and tested for the ambient temperature oxidation of CO. The catalysts were prepared by Precipitation from an ethanol/metal acetate solution and the addition of small quantities of water was found to result in a mixed acetate precursor with surface areas >200 m2 g−1, considerably higher than those prepared by conventional Precipitation methods. The surface area of the final calcined mixed oxide was found to be dependent upon the initial water concentration. XRD and FT-IR analysis indicated that the addition of water promoted the formation of carbonate species in the amorphous acetate precursor, with high resolution TEM and STEM showing the material to consist of spherical agglomerations of fibrous strings of ca. 30 nm length. This is in contrast to the material prepared in the absence of water, using the same SAS methodology, which typically yields quasi-spherical particles of 100 nm size.