solid state

固态
  • 文章类型: Journal Article
    近年来,由于原料供应问题,某些药物短缺。这些通常与活性成分有关,但也可能影响赋形剂。乳糖是压片中最常用的赋形剂之一,有两种异头和几种固态形式。这项研究的目的是利用来自乳制品侧流的乳糖,并将其与直接压缩中的商业参考进行比较。这将是一个可持续的选择,并将在危机期间确保国内供应。两种乳糖,喷雾干燥和冷冻干燥,进行了评估。乳糖与微晶纤维素以不同比例混合,润滑剂和助流剂,并对制剂的流动性和压片性进行了表征。完全无定形和小颗粒大小的喷雾干燥乳糖流动不充分,但表现出良好的压片性。较大的颗粒大小,冷冻干燥的乳糖表现出足够的流动性和比商业参考更好的可压性。然而,使用研究性乳糖制剂时,崩解和药物释放较慢。这很可能是由于残留的牛奶蛋白质,尤其是酪蛋白,在乳糖中。总的来说,研究乳糖为在危机情况下使用这种侧流产品提供了希望,但需要提高其性质和/或纯度。
    During recent years there have been shortages of certain drugs due to problems in raw material supply. These are often related to active ingredients but could also affect excipients. Lactose is one of the most used excipients in tableting and comes in two anomeric and several solid-state forms. The aim of this study was to utilize lactose from a dairy side-stream and compare it against a commercial reference in direct compression. This would be a sustainable option and would secure domestic availability during crises. Two types of lactose, spray-dried and freeze-dried, were evaluated. Lactose was mixed with microcrystalline cellulose in different ratios together with lubricant and glidant, and flowability and tabletability of the formulations was characterized. The fully amorphous and small particle-sized spray-dried lactose flowed inadequately but exhibited good tabletability. The larger particle-sized, freeze-dried lactose exhibited sufficient flow and better tabletability than the commercial reference. However, disintegration and drug release were slower when using the investigational lactose formulations. This was most likely due to remaining milk proteins, especially caseins, in the lactose. Overall, the investigational lactose provides promise for the use of such a side-stream product during crisis situations but enhancing their properties and/or purity would be needed.
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  • 文章类型: Journal Article
    自成立以来,使用温度来产生或改变材料,但是用于这种目的的压力超过几十大气压的应用很少被观察到。然而,压力是一个非常有效的热力学变量,越来越多地用于产生新材料或改变现有材料的性质。由于设计用于模拟固态的计算方法通常使用环境压力下的结构数据进行调整,从计算的角度来看,将它们应用于高压问题是对其有效性的高度挑战性测试。然而,使用量子化学计算,通常在密度泛函理论(DFT)的水平上,已经反复被证明是一个伟大的工具,可以用来预测特性,可以在以后被实验者证实,并解释,在分子水平上,高压实验的观察。本文的主要目标是编译,分析,并综合了在承受高压条件的分子晶体中使用DFT的工作结果,以便对这些最新计算提供的可能性进行概述。
    Since its inception, chemistry has been predominated by the use of temperature to generate or change materials, but applications of pressure of more than a few tens of atmospheres for such purposes have been rarely observed. However, pressure is a very effective thermodynamic variable that is increasingly used to generate new materials or alter the properties of existing ones. As computational approaches designed to simulate the solid state are normally tuned using structural data at ambient pressure, applying them to high-pressure issues is a highly challenging test of their validity from a computational standpoint. However, the use of quantum chemical calculations, typically at the level of density functional theory (DFT), has repeatedly been shown to be a great tool that can be used to both predict properties that can be later confirmed by experimenters and to explain, at the molecular level, the observations of high-pressure experiments. This article\'s main goal is to compile, analyze, and synthesize the findings of works addressing the use of DFT in the context of molecular crystals subjected to high-pressure conditions in order to give a general overview of the possibilities offered by these state-of-the-art calculations.
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  • 小角中子散射(SANS)是研究软凝聚态物质的一种强大而新颖的工具,包括用于药物发现和递送的微观和纳米材料。样品暴露于中子束,发生中子散射,将其作为散射角的函数进行研究,以推断有关材料动力学和结构的各种信息。该技术在生物医学研究中变得非常流行,以研究结构生物学的各个方面。关于大异构的低分辨率信息,使用氘标记和溶剂对比变化可获得溶液中溶解的生物大分子复合物。本文回顾了SANS技术的基础知识,它在药物递送研究中的应用,及其在生物医学研究中的现状。这篇文章涵盖并概述了生物结构的精确表征(膜,囊泡,溶液中的蛋白质),介孔结构,胶体,和表面活性剂,以及环糊精复合物,脂质复合物,聚合物纳米颗粒,等。,在中子散射的帮助下.SANS作为探索复杂生物分子世界的媒介不断发展,提供有关结构的信息,composition,和各种成分的排列。随着数据减少和新中子研究设施的开发,建模软件自动化的提高,SANS有望继续成为生物医学研究的主流。
    Small Angle Neutron Scattering (SANS) is a powerful and novel tool for the study of soft condensed matter, including the microscopic and nanomaterials used for drug discovery and delivery. The sample is exposed to a neutron beam, and neutron scattering occurs, which is studied as a function of the scattering angle to deduce a variety of information about the dynamics and structure of the material. The technique is becoming very popular in biomedical research to investigate the various aspects of structural biology. The low-resolution information on large heterogeneous, solubilized biomacromolecular complexes in solution is obtained with the use of deuterium labelling and solvent contrast variation. The article reviews the basics of the SANS technique, its applications in drug delivery research, and its current status in biomedical research. The article covers and overviews the precise characterization of biological structures (membranes, vesicles, proteins in solution), mesoporous structures, colloids, and surfactants, as well as cyclodextrin complexes, lipid complexes, polymeric nanoparticles, etc., with the help of neutron scattering. SANS is continuously evolving as a medium for exploring the complex world of biomolecules, providing information regarding the structure, composition, and arrangement of various constituents. With improving modelling software automation in data reduction and the development of new neutron research facilities, SANS can be expected to remain mainstream for biomedical research.
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  • 文章类型: Journal Article
    本研究的重点是生物制药分类系统(BCS)II类分子的干磨。这些分子具有有限的生物利用度,因为它们的水溶性低,水润湿性差,溶解速率低。为了改善这些性能,使用两种不同类型的设备:Pulverisett0®和CryoMill®研磨吲哚美辛(IND)和尼氟灭酸(NIF)。对研磨的样品进行表征并与商业分子进行比较。IND显示改良的固态,例如,由于研磨过程,表面结晶度降低和水蒸气吸附从2倍增加到5倍。获得的溶解度数据导致溶解度提高高达1.2倍,并且初始溶解动力学增加:原始晶体的溶解药物为2%,而研磨样品的溶解药物为25%。对于没有结晶度降低的NIF,在研磨后没有观察到表面性质的变化和溶解度的改善。此外,与原始药物相比,研磨的颗粒似乎更团聚,导致溶出速率没有变化。IND溶解度和溶解增强可归因于表面积的改性,药物结晶度降低,由于与研磨过程引起的药物晶体紊乱相关的特定行为,吸水率增加。
    This study focuses on the dry milling of biopharmaceutical classification system (BCS) class II molecules. These molecules have a limited bioavailability because of their low aqueous solubility, poor water wettability and low dissolution rate. In order to improve these properties, indomethacin (IND) and niflumic acid (NIF) were milled using two different types of equipment: Pulverisette 0® and CryoMill®. Milled samples were characterized and compared to commercial molecules. IND shows a modified solid state, like surface crystallinity reduction and an increase in water vapor adsorption from to 2- up to 5-fold due to milling processes. The obtained solubility data resulted in an improvement in solubility up to 1.2-fold and an increase in initial dissolution kinetics: 2% of dissolved drug for original crystals against 25% for milled samples. For NIF no crystallinity reduction, no change of surface properties and no solubility improvement after milling were noticed. In addition, milled particles seemed more agglomerated resulting in no changes in dissolution rate compared to the original drug. IND solubility and dissolution enhancement can be attributed to the modification of surface area, drug crystallinity reduction, and water sorption increase due to specific behavior related to the drug crystal disorder induced by milling process.
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  • 文章类型: Journal Article
    Controlling drug crystallization is one of the important issues in pre-formulation study. In recent years, advanced approaches including the use of tailor-made additives have gathered considerable attention to control crystallization behavior of drugs. This review focuses on the use of hydrophilic cyclodextrins (CDs) as additives for controlling drug crystallization. CDs affect the crystallization of drugs in solution and in solid state based on a host-guest interaction. For example, 2,6-di-O-methyl-β-CD and 2-hydroxybutyl-β-CD suppressed solution-mediated transition of drugs during crystallization by the host-guest interaction; as a result, metastable forms selectively precipitated in solution. The use of CDs in crystal engineering provided an opportunity for the detection of a new polymorph by changing the crystallization pathway. It was also possible to modify crystal morphology (i.e., crystal habit) by selective suppression of crystal growth on a certain direction based on the host-gust interaction. For solid formulation, stable amorphous drug/CDs complex under humid conditions was prepared using two different CDs. An overview of some recent progress in the use of CDs in crystal engineering and in amorphous formulation is described in this review.
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  • 文章类型: Journal Article
    The aim of this study was to demonstrate the usefulness of T2 measurements conducted with a time-domain NMR (TD-NMR) for the characterization of active pharmaceutical ingredients (APIs) containing solid dosage forms. A solid dispersion (SD) and a physical mixture (PM) consisting of indomethacin (IMC) and polyvinylpyrrolidone (PVP) were prepared at different weight ratios as test samples, and then their T2 relaxation curves were measured by TD-NMR. The T2 relaxation curve of IMC was quite different from that of PVP by nature. T2 values of the SD and PM samples became gradually shortened with increasing IMC content. No difference in T2 relaxation curves was observed between SD and PM. By analyzing the T2 relaxation curves in detail, we succeeded in precisely quantifying the IMC contents incorporated in the samples. Next, this study evaluated the T2 relaxation curves of amorphous and crystalline states of powdered IMC. T2 relaxation rate of crystalline IMC was slightly but significantly higher than that of amorphous IMC, proving that the T2 measurement was sensitive enough to detect these differences. Finally, a thermal stress was imposed on SD and PM samples at 60°C for 7 d, and then an amorphous-to-crystalline transformation occurred in IMC in the PM sample and was successfully monitored by T2 measurement. We believe that T2 measurement by TD-NMR is a promising analysis for the characterization of APIs in solid dosage forms, including SD-based pharmaceuticals.
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  • 文章类型: Journal Article
    我们对纯固体CH2DOH和天体物理学相关混合物进行了新的实验研究。在17K的超高真空条件下吸收固体样品,并通过中红外透射光谱分析。折射率,密度,测量纯固体CH2DOH的中IR波段强度值。还测量了CH2DOH:H2O的折射率,CH2DOH:CO,和CH2DOH:CH3OH混合物。对于所有样品,研究了主带分布的热演化。我们使用了干涉激光技术(HeNe激光,λ=543.5nm)以测量样品厚度,并从干涉曲线的幅度开始测量折射率的数值方法。我们通过洛伦兹-洛伦兹关系获得了冰密度。为了计算带强度值,我们使用了积分带强度相对于柱密度的线性拟合。将在17K下沉积的样品加热至它们的升华温度。在选定的温度下获取光谱以研究它们的热演化。鉴于其与天文红外光谱解释的相关性,对结果进行了讨论。
    We present a novel experimental study on solid CH2DOH pure and in astrophysical relevant mixtures. Solid samples were accreted under ultra high vacuum conditions at 17 K and were analyzed by mid-infrared transmission spectroscopy. Refractive index, density, and mid-IR band strength values were measured for pure solid CH2DOH. The refractive index was also measured for CH2DOH:H2O, CH2DOH:CO, and CH2DOH:CH3OH mixtures. For all samples, the thermal evolution of the main band profile was studied. We used the interference laser technique (HeNe laser, λ = 543.5 nm) to measure the samples thickness and a numerical method to measure the refractive index starting from the amplitude of the interference curve. We obtained the ice density through the Lorentz-Lorenz relation. To calculate the band strength values we used the linear fit of the integrated band intensities with respect to the column densities. Samples deposited at 17 K were warmed up to their sublimation temperature. Spectra were taken at selected temperatures to study their thermal evolution. The results are discussed in view of their relevance for the interpretation of astronomical IR spectra.
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  • 文章类型: Journal Article
    The NMR chemical shifts of two azoles and one benzazole whose crystal structures present polymorphism have been computed using the GIPAW approach. 15 N and 13 C nuclei have been studied. Statistical analysis of the computed 13 C and 15 N chemical shifts indicates that the GIPAW chemical shifts reproduce with a high degree of accuracy those experimentally reported. This methodology can be used to identify other polymorphic crystal structures.
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  • 文章类型: Journal Article
    The aim of this study was to demonstrate the usefulness of the time domain nuclear magnetic resonance (TD-NMR) method to characterize the crystalline state of active pharmaceutical ingredients (APIs) containing solid dosage forms. In this study, carbamazepine and indomethacin are used as models for poorly water-soluble APIs. First, we measured the T1 and T2 relaxation behavior of crystalline and amorphous APIs. From the results, we were able to confirm that the T1 relaxation time measured by TD-NMR is an effective parameter for distinguishing between crystalline and amorphous states in powdered APIs. We then examined physical mixtures of APIs with polyvinylpyrrolidone and their solid dispersion. The results indicated that TD-NMR allows the evaluation of not only the crystalline form of APIs but also the miscibility of APIs and polymers. In the final phase of the study, we conducted continuous monitoring of the crystalline state of APIs incorporated into physical mixtures during the thermal stress test. Conversion to crystalline forms of the APIs was successfully monitored based on the T1 relaxation behavior. Our findings led us to conclude that TD-NMR is useful as a new approach to evaluate the crystalline state of APIs.
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  • 文章类型: Journal Article
    To investigate the minimum number of SiPM detectors required for solid-state digital photon counting (DPC) oncologic whole-body 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) positron emission tomography (PET)/X-ray computed tomography (CT).
    A DPC PET/CT (Vereos, Philips) with 23,040 1-to-1 crystal-to-detector couplings was utilized. [18F]FDG PET/CT of a uniformity phantom and 10 oncology patients selected by block randomization from a large clinical trial were included (457 ± 38 MBq, 64 ± 22 min p.i, body mass index (BMI) of 14-41). Sparse-ring PET configurations with 50 % detector reduction in tangential and axial directions were analyzed and compared to the current full ring configuration. Resulting images were reviewed blindly and quantitatively over detectable lesions and the liver.
    One hundred twelve lesions (d = 10 to 95 mm) were analyzed in the patient population. All lesions remained visible and were demonstrated without compromised image quality under all BMIs in the 50 % sparse detector configurations despite the DPC PET system sensitivity reduction to 1/4th. An excellent consistency of SUVmax measurements of lesions with an average of 5 % SUVmax difference was found between dPET of full and sparse configurations.
    The feasibility of either expanding the axial field of view (FOV) by a factor of two or halving the number of detectors was demonstrated for solid-state digital photon counting PET, thus either potentially enabling cost reduction or extended effective axial FOV without increased cost.
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