Onečišćenje, odnosno utjecaj plastike na okoliš, jedan je od globalnih problema današnjice, a poznat je još od davnina. Zbog svoje široke upotrebe plastiku možemo naći u gotovo svim sastavnicama ...okoliša, gdje može štetno utjecati na žive organizme. Plastika, unatoč svojoj praktičnosti, sadrži štetne kemikalije, aditive, poput poput di(2-etilheksil)ftalata (DEHP), mono(2-etilheksil)ftalata (MEHP), bisfenola A (BPA), polikloriranih bifenila (PCB) i drugih. U ovome radu dan je pregled istraživanja štetnog djelovanja aditiva na ekosustav temeljen na raznim testovima toksičnosti.
Biodiesel produced from waste feedstocks can play a significant role in fighting climate change, improperly disposed waste and growing energy demand. Waste feedstocks such as used cooking oil have a ...great potential for energy production. However, they often have to be purified from free fatty acids prior to biodiesel production. Extractive deacidification with deep eutectic solvents is a promising alternative to conventional purification methods.
To evaluate the process of extractive deacidification of waste cooking oil, a full set of physical, hydrodynamic and kinetic data were experimentally determined on a laboratory scale. Hydrodynamic and kinetic experiments were performed in three geometrically similar jacketed agitated vessels. Vessels were equipped with axial flow impeller (four pitched blade impeller). Physical properties (density, viscosity and surface tension) were experimentally determined. Preliminary hydrodynamic experiments involved several model systems without mass transfer. As a result, correlation between power number and Reynolds number as well as scale-up criterion was developed. Obtained dependencies were correlated with the physical properties. Mixing intensity for achieving complete dispersion was determined. Second stage of investigation involved two sets of experiments, hydrodynamic and kinetic, with interphase mass transfer (the extraction of free fatty acids from waste cooking oil with deep eutectic solvent, potassium carbonate:ethylene glycol, 1:10). Obtained results enabled understanding interphase mass transfer and prediction of mass transfer coefficient from the derived dimensionless correlations. The values of volumetric mass transfer coefficients were smaller for the dispersed phase, indicating that the prevailing mass transfer resistance was within the droplets. The working hypothesis was that the same process result should be achieved at the same dispersion rate, and that hypothesis was confirmed – at all scales extraction efficiency was 97.9 ± 0.1%.
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•Investigation of thermodynamic, hydrodynamic and kinetic aspects and mass transfer.•Free fatty acids were removed from WCO via extractive deacidification with DES.•Scale-up criteria for extractive deacidification were derived for the first time.•Volumetric mass transfer coefficients were independent on the vessel size.
Because of the specific thermodynamic properties of active pharmaceutical ingredients, the process of crystallization often meets implementation challenges in the pharmaceutical industry. Therefore, ...it is essential to select the appropriate method and system for the crystallization of a drug. Ceritinib, an active ingredient in the treatment of lung cancer, was formed as a result of pH modification during the cooling crystallization of ceritinib dihydrochloride solution. By carrying out processes in various solvent systems, several polymorphs were produced. A combination of forms B and C was generated in the ethanol–water system, resulting in smaller crystals. The acetone–water system produced pure form A, which has larger crystals and is more applicable for forthcoming studies. To additionally enhance granulometric properties, ceritinib form A was recrystallized in tetrahydrofuran at different temperatures using antisolvent crystallization. Crystallization at a higher saturation temperature results in larger and more compact crystals, which enhances filtration and drying.
Abstract
The possibility of spherical agglomeration was investigated for two active pharmaceutical ingredients from different classes of the Biopharmaceutics Classification System. The effects of ...different batch crystallization solvent systems on the granulometric properties and structures of dronedarone hydrochloride and ceritinib were investigated. Light and stereomicroscopy were used to determine the size and shape of the agglomerates, while X‐ray powder diffraction was applied to assess the changes in polymorphic form. Since the change in the solvent system had no effect on the crystal structure but did alter the size and shape of the crystals, dissolution experiments were carried out to determine drug release profiles.
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