1,720,988 research outputs found
Determinazione di aminofenazone e clortenossazina in una forma farmaceutica mediante HPLC
No full textviene descritto un metodo di cromatografia liquida ad alta pressione (HPLC) in fase inversa per determinazione quantitativa di aminofenazone e clortenossazina in una forma farmaceutic
Enhanced Dissolution Profiles of Furosemide Treated by Supercritical Antisolvent Technology with Crospovidone
No full textSupercritical Antisolvent Precipitation of Piroxicam Systems: Preliminary Experiments.
No full textThe purpose of this study is to investigate the influence of supercritical CO2 on the physicochemical properties of Piroxicam (PXC), a poorly soluble drug. The supercritical anti-solvent (SAS) technique was used to precipitate the drug at the pressure of 100 and 120 bar from three different solvents (acetone, ethylacetate and dichloromethane) to study how they would affect the final product. The samples were analyzed before and after the treatment to highlight possible changes in the habitus of the crystals
Different Approaches for the Modeling of the solubility of Pharmaceutical Compounds in Supercritical Carbon Dioxide
No full textRECOVERY OF POLYPHENOLS FROM DECCAFEINATED GREEN COFFEE WITH NATURAL METHODS
No full textABSTRACT
Decaffeination process using natural methods (eg. water) is a interesting target as it reduces the risk of contamination produced with the use of solvent, such as dichloromethane. The use of water in addition to removing caffeine from green coffee, also determines the removal of other important components such as sugars and polyphenols. Especially the polyphenols recovery is being study for the possibility of reuse in different fields such as pharmaceuticals, cosmetics or food, thereby ensuring an economic return. The aim of this study was to identify the method for the recovery of polyphenolic compounds with low/medium cost, which can be extended on a larger scale. Different samples of green coffee were decaffeinated with different methods: solvents, supercritical extraction (SCCO2) and an experimental apparatus, using water and activated carbon. For each sample was analysed the polyphenolic profile. The phenolic content ranges from 1% in DCM and SCCO2 extract to 52.2% in water extract; from the latter the recovery was in a variable percentage from 52.36 to 64.27%
Removal of Nickel by Sorption on Anaerobic Sludge. Effects on Methane Production
No full textBiosorption of Ni (II) on industrial anaerobic sludge was investigated at 308.1 K and 7.5 pH in a batch reactor. The effective metal sorption capacity was of 10.25 mgNi/gTSS. Equilibrium data were fitted using Langmuir and Freundlinch models and the results compared by non-linear regression. A better agreement with experimental data was shown by Freundlich isotherm. Effects on methane production were also studied with the purpose of investigate if the biosorption process could occur without any variation in the ability of the anaerobic sludge to produce biogas. The results reveal that methane production rapidly drops for low metal concentration and that it can be partially recovered with further metal addition
Solubility of pharmaceutical compounds in supercritical carbon dioxide
No full textThe manuscript aims to estimate the solubility behavior of pharmaceutical compounds in supercritical fluids using an activity coefficient model based on linear solvation energy relationships. The parameters of this model were further generalized as a function of the properties of the pharmaceutical compounds. The selected compounds include antioxidants, antibiotics, steroids and anti-inflammatory and their solubility data were collected from literature. This model is able to estimate the solubility of the pharmaceutical compounds in supercritical carbon dioxide within acceptable accuracy for more than 60% of the proposed systems
Piroxicam solid state studies after processing with SAS technique
No full textSupercritical carbon dioxide (SCO2) was used as anti-solvent to precipitate Piroxicam, a nonsteroidal anti-inflammatory drug, from different organic solvents (acetone, ethyl acetate and dichloromethane). Physicochemical properties of the samples were analyzed before and after the treatment to highlight possible changes in the form of the crystals. The solid state analysis of both products untreated and treated with CO2, showed that the applied method choose a particle size reduction and transition to the pure _ form resulting in needle-shaped crystals, regardless of the chosen solvent. In order to identify which process was responsible for the above results, Piroxicam was further precipitated from the same three solvents by traditional evaporation method (RV-samples). The dissolution profiles of Piroxicam processed in SCO2 show a better dissolution performance of Piroxicam over their corresponding system obtained by traditional evaporation method
Antisolvent Precipitation of Vitamin B6: A Thermodynamic Study
No full textA supercritical antisolvent precipitation process was applied to recrystallize vitamin B6 from ethanol solution in CO2.
By means of the PengRobinson equation of state (PR EoS), we performed preliminary studies to identify better operative
conditions in terms of the organic solvent, pressure, temperature, and ability to carry a precipitate of the solute. This simulation was
also considered to estimate the vitamin B6 particle size starting from supersaturation conditions
Extraction Behavior of Lipids Obtained from Spent Coffee Grounds Using Supercritical Carbon Dioxide
No full textSupercritical carbon dioxide (sc-CO2) extraction was applied to extract lipids from spent coffee grounds. The effects of different process conditions on the extraction yield and composition of the extracts were investigated by response surface methodology.
A comparison of the experimental results with those obtained by conventional solvent extraction was also performed. In all these samples, the main fatty acids were rich in palmitic and linoleic acids. Moreover, a new method was developed and validated for the gas chromatographic analysis of sterols and tocopherols.
The results demonstrate that sc-CO2 extraction is principally a potential candidate method for the extraction of lipids and high value-added compounds from residues/by-products
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