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关键词： amorphous solid dispersion   nanodroplet   release performance   solubility enhancement  

摘要： Dissolution of amorphous solid dispersions (ASD) can lead to the formation of amorphous drug-rich nano species (nanodroplets) via liquid-liquid phase separation or glass-liquid phase separation when the drug concentration exceeds the amorphous solubility. These nanodroplets have been shown to be beneficial for ASD performance both in vitro and in vivo. Thus, understanding the generation and stability of nanodroplets from ASD formulations is important. In this study, the impacts of polymer selection and active pharmaceutical ingredient (API) physicochemical properties (wet glass transition temperature (T-g) and log P) on nanodroplet release were studied. Six APIs with different physicochemical properties were formulated as ASDs with two polymers, polyvinylpyrrolidone/vinyl acetate (PVPVA) and hydroxypropyl methylcellulose acetate succinate (HPMCAS). Their release performance was evaluated using both powder and surface normalized dissolution of compacts. In general, HPMCAS-based dispersions resulted in higher drug release compared to PVPVA-based dispersions. The two polymers also exhibited different trends in nanodroplet formation as a function of drug loading (DL). PVPVA ASDs exhibited a "falling-off-the-cliff" effect, with a dramatic decline in release performance with a small increase in drug loading, while HPMCAS ASDs exhibited a negative "slope" in the release rate as a function of drug loading. For both polymers, low T-g compounds achieved higher levels of nanodroplet formation compared to high T-g compounds. The nanodroplets generated from ASD dissolution were also monitored with dynamic light scattering, and HPMCAS was found to be more effective at stabilizing nanodroplets against size increase. Insights from this study may be used to guide formulation design and selection of excipients based on API physicochemical properties.

关键词： Pear   Saccharomyces uvarum   Patagonia   Fermentation   Sorbitol   Sensory analysis  

摘要： The production of pome fruits as pears and apples, as well as their derived industries, is of great economic importance in North Patagonia. The elaboration of fermented beverages as cider or perry has evidenced a substantial diversification during the last years, with the evaluation of different fruit varieties, yeast starters and technological changes. In this work, two cryotolerant yeasts belonging to the species Saccharomyces uvarum were evaluated at laboratory and pilot scale in sterile and no-sterile pear must. One of the strains was originally isolated from apple chicha (strain NPCC1314) and the other from apple cider (strain NPCC1420) in Patagonia. Both physicochemical and sensory features of the fermented products were evaluated. Both strains were able to successfully complete the fermentations, although strain NPCC1420 showed the better kinetic properties including a faster sugar consumption than the strain NPCC1314. Both strains showed excellent implantation capacity, but the fermented products showed different chemical profiles. The perry fermented with the strain NPCC1314 was characterized by better sensory attributes as assessed by trained panelists and a greater acceptance for untrained public than the same fermented with the strain NPCC1420. The two strains were able to consume sorbitol, both in pear must and in agar-plates supplemented with sorbitol as the sole carbon source. This ability is described for the first time in S. uvarum, at least for the two strains evaluated in this work.

关键词： 应用型本科院校   工科物理化学   理论联系实际  

摘要： 基于应用型本科院校的实际情况和学生的培养特色,本文通过优化教学内容,改进教学方法和科学合理地进行教学设计,强调了物理化学知识与学生工科专业特色的联系,突出了基础理论与生活及生产实际应用并重,从而学生学习物理化学的兴趣和积极性以及学生对于物理化学知识的理解及深化、拓展及应用、理论联系实践的能力得到显著提升,并为后续专业课程的学习打下良好的基础。

关键词： 对分课堂   问题教学法   物理化学   教学创新  

摘要： 该文基于课堂教育现状,结合物理化学课程的特点,将对分课堂融合问题驱动教学法应用到物理化学课程教学,以多组分系统热力学为例阐述了具体实施步骤与方法,总结了实施过程中应注意的问题。教学实践表明,对分课堂融合问题驱动教学法能够有效提高课堂的教学效率,有助于培养学生的自主学习能力和创新能力。

关键词： Positively-charged amphiphilic chitosan   Mucoadhesive   Cytocompatible   Cancer therapy  

摘要： Two samples of N-(2-hydroxy)-propyl-3-trimethylammonium, O-palmitoyl chitosan (DPCat) with different av-erage degrees of quaternization named as DPCat35 ((DQ) over bar = 35%) and DPCat80 ((DQ) over bar = 80%), were successfully syn-thesized by reacting glycidyltrimethylammonium chloride (GTMAC) with O-palmitoyl chitosan (DPCh) derivative ((DS) over bar = 12%). Such amphiphilic derivatives of chitosan were fully water-soluble at 1.0 < pH < 12.0 and showed significant electrostatic stability enhancement of a self-assembly micellar nanostructure (100-320 nm) due to its positively-charged out-layer. In vitro mucoadhesive and cytotoxicity essays toward healthy fibroblast cells (Balb/C 3T3 clone A31 cell), human prostate cancer (DU145) and liver cancer (HepG2/ C3A) cell lines revealed that the biological properties of DPCat derivatives were strongly dependent on (DQ) over bar. Ad-ditionally, DPCat35 had better interactions with the biological tissue and with mucin glycoproteins at pH 7.4 as well as exhibited potential to be used on the development of drug delivery systems for prostate and liver cancer treatment. (c) 2021 Elsevier B.V. All rights reserved.

关键词： Coacervate polyphosphate   Drug delivery   Caffeine   Chlorhexidine   Gel-like platform  

摘要： This paper reports on the synthesis and characterization of gel-like calcium polyphosphate coacervates (Ca-PPCs) with three different [P]:[Ca] ratios as new matrixes for drug release. Caffeine and chlorhexidine were used as model drugs, showing encapsulation efficiency of up to 95.4% and 70.4%, respectively. Based on the correlation coefficient (r(2)) values, different in vitro release behaviors were determined. While the caffeine release followed the Weibull model, the chlorhexidine release was best described by the Korsmeyer-Peppas model. The caffeine-loaded coacervate sample with the highest Ca2+ concentration (CAFPCa0.5) showed the highest incorporation and a total drug release within 720 min. The Ca-PPC-drug interactions were evaluated by infrared and Raman spectroscopies. The Ca2+ concentration, drug molecule size and intermolecular drug/matrix interactions determined the incorporation and release of drugs in the polyphosphate coacervates. High calcium concentration led to a Ca-PPC with small and tight "cage-like" structure that better incorporated caffeine molecules because of their 4.3 times smaller size compared to chlorhexidine. In addition, caffeine interacted through van der Waals' forces with polyphosphate and its release from the coacervates was most likely to occur in relation to chlorhexidine, which interacted with the coacervates through hydrogen bonding. Thus, the calcium polyphosphate coacervates loaded with the proposed drugs can be competitive and promising as drug delivery systems.

关键词： 混合式教学   物理化学实验   自主学习   高阶认知能力  

摘要： 以提升大学生的综合能力、创新思维和科学素养为目的,以泛雅网络教学平台为依托,探索混合式教学在物理化学实验课程中的实践模式。课程对传统的实验授课模式和评价方式进行改革,建设完善的线上教学资源;通过“三阶段四环节”的混合式教学模式展开实验教学,重在培养学生的自主学习和高阶认知能力,加强学习深度;采用“线上+线下+实践”的课程评价模式,以能力产出为导向,对学生的综合能力进行评价,通过实践推动理工科实验课程由传统课堂向智慧课堂的转化。

关键词： High-amylose corn   Waxy corn   Dry-extrusion-cooking   Gluten-free  

摘要： The suitability of corn fractions (break meal: 250-500 mu m;flour: < 150 mu m) from hybrids with different amylose contents (conventional: 18%;high-amylose: 42%;waxy: 2%) and their blends, to produce co-extruded snacks was assessed. Corn flour exhibited a higher content in total soluble phenolic acids (+34%) than break meal. The high-amylose hybrid maintained a higher antioxidant capacity and phenolic acid content (+52% for soluble and + 54% for cell-wall bound phenolic acids), even after extrusion, than the conventional one. Because of its gelatinization properties (high pasting and peak temperatures;low maximum viscosity), the high-amylose hybrid produced co-extruded snacks characterized by low section areas and large inner areas. The blends led to snacks whose features (sections and inner areas, porosity and hardness) did not follow a linear trend with the amylose content, suggesting the need for further studies to better understand the starch interactions that take place among the various hybrids.

关键词： 物理化学性能   有机溶液   原子量   物理性能   大气压  

摘要： 物理性能。氢的原子量1.00797,分子量2.01594,在0℃和1大气压(atm)下的密度为0.08987 g/L,在空气中的浮力1.205 g/L,其他性能见表1。氢在水中的溶解度为0℃时每体积水溶解0.0214体积,20℃时溶解0.018体积,50℃溶解0.016体积,它稍溶于有机溶液中。许多金属可吸收氢,钯在这方面可大显身手。

关键词： acyclovir sodium   drug stability   HPLC   polypropylene bag   refrigerated  

摘要： Purpose. To investigate the long-term chemical and physical stability of 5-mg/mL acyclovir solution in polypropylene bags stored at 5 degrees C +/- 3 degrees C for 2 months in order to determine the feasibility of batch production by a centralized intravenous additive service. Methods. Eight empty 100-mL polypropylene bags (bags A) and 8 empty 250-mL bags (bags B) were respectively filled with 60 mL and 200 mL of 5-mg/mL acyclovir and 0.9% sodium chloride injection (NaCl) under aseptic conditions through a semiautomated manufacturing process and vacuum packed before storage at 5 degrees C +/- 3 degrees C. Four bags A and 4 bags B were tested for chemical stability via a stability-indicating high-performance liquid chromatography (HPLC) method immediately after preparation (time 0) and after 7, 14, 21, 28, 35, 42, and 63 days. Samples for microbiological assay were collected on days 0 and 63 from 4 bags A and 4 bags B immediately after breaking the vacuum. Osmolality, pH, and physical stability were assessed by visual examination, Subvisible particle counting was performed on 6 additional bags (3 each of bags A and B). Results. Mean percentage loss of acyclovir relative to the mean experimental concentration at time 0 was below 5% over the 63-day study period.. No significant differences of pH, no change in color and no precipitate were observed during the study. Subvisible particle counts were compliant with European Pharmacopoeia requirements. Acyclovir solutions remained sterile over the 63 days of the study. Conclusion. Extemporaneously prepared acyclovir 5 mg/mL solutions in 0.9% NaCl stored in polypropylene bags were chemically and physically stable over 63 days when stored at 5 degrees C +/- 3 degrees C.