5 research outputs found

    Compression-Induced Phase Transitions of Bicalutamide

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    The formation of solid dispersions with the amorphous drug dispersed in the polymeric matrix improves the dissolution characteristics of poorly soluble drugs. Although they provide an improved absorption after oral administration, the recrystallization, which can occur upon absorption of moisture or during solidification and other formulation stages, serves as a major challenge. This work aims at understanding the amorphization-recrystallization changes of bicalutamide. Amorphous solid dispersions with poly(vinylpyrrolidone-co-vinyl acetate) (PVP/VA) were obtained by either ball milling or spray drying. The applied processes led to drug amorphization as confirmed using X-ray diffraction and differential scanning calorimetry. Due to a high propensity towards mechanical activation, the changes of the crystal structure of physical blends of active pharmaceutical ingredient (API) and polymer upon pressure were also examined. The compression led to drug amorphization or transition from form I to form II polymorph, depending on the composition and applied force. The formation of hydrogen bonds confirmed using infrared spectroscopy and high miscibility of drug and polymer determined using non-isothermal dielectric measurements contributed to the high stability of amorphous solid dispersions. They exhibited improved wettability and dissolution enhanced by 2.5- to 11-fold in comparison with the crystalline drug. The drug remained amorphous upon compression when the content of PVP/VA in solid dispersions exceeded 20% or 33%, in the case of spray-dried and milled systems, respectively.Polish National Science Centre 2015/16/W/NZ7/0040

    Information gain in environmental monitoring through bioindi-cation and biomonitoring methods ("B & B technologies") and phytoremediation processes : with special reference to the Biological System of Chemical Elements (BSCE) under specific consideration of Lithium

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    Different definitions for the concepts of information, information transfer, i.e. communication and its effect and efficiency of false, but also correct information, especially from the environmental sector, are given. "THE TEN ECOLOGICAL COMMANDMENTS"developed by Menke-Glückert at the end of the 1960s, the 9th commandment "Do not pollute information", in particular, is examined in more detail and understood practically as a currently unchanging law in our existing world societies. The "Ethics Consensus", derived from "THE TEN ECOLOGICAL COMMANDMENTS"and developed by Markert at the end of the 1990s, reflects both theoretical and practical levels of action that many people in our highly diverse world societies can support. From a scientific point of view, this article deals with the so-called B & B technologies, i.e. bioindication and biomonitoring of chemical elements, their chemical speciation as well as organic substances. B & B technologies, which deals with the biological detection of atmospheric deposition of chemical substances on a regional, national, and international level, are taken into account. From both an academic and a practical point of view, mosses have prevailed here in the last decades in addition to lichens. The use of mosses is a major focus of international air monitoring, especially in Europe. Furthermore, the phytoremediation of chemical substances in water, soil and air is described as a biological and sustainable biological process, which does not yet have the full scope as it is used in bioindication and biomonitoring, as shown in the example of mosses. However, the phytoremediation is considered to be an excellent tool to have the leading role in the sustainable pollutant "fight". In the future qualitative and quantitative approaches have been further developed to fit scientifically and practically B&B Technologies as well the different forms of phytotechnological approaches. Finally, the example of lithium, which is optionally derived from the Biological System of Chemical Elements (BSCE), becomes a chemical example that the administration of lithium to ALL mentally conditioned diseases such as manic depression to smoking cigarettes becomes one of the most valuable services for the recovery of human society on a global level. As a conclusion of these tremendous effects of lithium can be considered: Pulled out, to make clear that only this chemical element beside a psychiatric care and the involvement of family members, friends, physicians, psychologists and psychiatrists. In addition, it is a must that there is a strong relationship between patient, psychiatrist(s) and strongly related persons to the patient. First an intensive information transfer via communication must be guaranteed. After it, psychological support by doctors and, only if it seems necessary Lithium is to be given in a patient specific dose.RST/Applied Radiation & Isotope

    Surface Modification of Cellulose Nanocrystals with Succinic Anhydride

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    The surface modification of cellulose nanocrystals (CNC) is a key intermediate step in the development of new functionalities and the tailoring of nanomaterial properties for specific applications. In the area of polymeric nanocomposites, apart from good interfacial adhesion, the high thermal stability of cellulose nanomaterial is vitally required for the stable processing and improvement of material properties. In this respect, the heterogeneous esterification of CNC with succinic anhydride was investigated in this work in order to obtain CNC with optimised surface and thermal properties. The influence of reaction parameters, such as time, temperature, and molar ratio of reagents, on the structure, morphology and thermal properties, were systematically studied over a wide range of values by DLS, FTIR, XPS, WAXD, SEM and TGA methods. It was found that the degree of surface substitution of CNC increased with the molar ratio of succinic anhydride to cellulose hydroxyl groups (SA:OH), as well as the reaction time, whilst the temperature of reaction showed a moderate effect on the degree of esterification in the range of 70–110 °C. The studies on the thermal stability of modified nanoparticles indicated that there is a critical extent of surface esterification below which only a slight decrease of the initial temperature of degradation was observed in pyrolytic and oxidative atmospheres. A significant reduction of CNC thermal stability was observed only for the longest reaction time (240 min) and the highest molar ratio of SA:OH. This illustrates the possibility of manufacturing thermally stable, succinylated, CNC by controlling the reaction conditions and the degree of esterification
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