空气相对湿度对喷雾干燥生产的影响

我国南北方相对湿度差别较大,相对湿度大,绝对湿含量过高会给喷雾干燥生产带来不利影响,如不调节进风温度有可能造成塔壁挂粉严重、产品水分含量超标、生产效率降低.相对湿度是设计喷雾干燥系统的重要参数.现以RGYP01-500型立式压力喷雾干燥塔生产奶粉为例进行阐述.     

Measurements of volatile compound contents in resins using a moisture analyzer

Hashimoto M, Nagano F, Endo K, Ohno H. Measurements of volatile compound contents in resins using a moisture analyzer. Eur J Oral Sci 2010; 118: 94–99. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci
The contents of volatile adhesive compounds, such as water, solvents, and residual unpolymerized monomers, affect the integrity and durability of adhesive bonding. However, there is no method available that can be used to rapidly assess the residual solvent or water contents of adhesive resins. This study examined the effectiveness of a digital moisture analyzer to measure the volatile compound contents of resins. Five self-etching adhesives and seven experimental light-cured resins prepared with different contents (0, 10, and 20% by weight) of water or solvents (acetone and ethanol) were examined in this study. The resins were prepared using different methods (with and without air blast or light-curing) to simulate the clinical conditions of adhesive application. Resin weight changes (% of weight loss) were determined as the residual volatile compound contents, using the moisture analyzer. After the measurements, the resin films were examined using a scanning electron microscope. The weight changes of the resins were found to depend on the amount of water or solvents evaporating from the resin. Water and solvents were evaporated by air blast or light-curing, but some of the water and solvents remained in the cured resin. The moisture analyzer is easy to operate and is a useful instrument for using to measure the residual volatile compound contents of adhesive resin.     

The biomechanical efficacy of a dressing with a soft cellulose fluff core in prophylactic use

In this work, we developed an experimental‐computational analysis framework which facilitated objective, quantitative, standardised, methodological, and systematic comparisons between the biomechanical efficacies of two fundamentally different dressing technologies for pressure ulcer prevention: A dressing technology based on cellulose fibres used as the core matrix was evaluated vs the conventional silicone‐foam dressing design concept, which was represented by multiple products which belong in this category. Using an anatomically‐realistic computer (finite element) model of a supine female patient to whom the different sacral dressings have been applied virtually, we quantitatively evaluated the efficacy of the different dressings by means of a set of 3 biomechanical indices: The protective efficacy index, the protective endurance, and the prophylactic trade‐off design parameter. Prior rigorous experimental measurements of the physical and mechanical behaviours and properties of each tested dressing, including tensile, compressive, and friction properties, have been conducted and used as inputs for the computer modelling. Each dressing was evaluated for its tissue protection performances at a new (from the package) state, as well as after exposure to moisture conditions simulating wet bedsheets. Our results demonstrated that the dressing with the fluff core is at least as‐good as silicone‐foams but importantly, provides the best balance between protective performances at its “new” condition and the performance after being exposed to moisture. We conclude that preventative dressings are not equal in their prophylactic performances, but rather, the base technology, the ingredients, and their arrangement in the dressing structure shape the quality of the delivered tissue protection.     

Can breathing circuit filters help prevent the spread of influenza A (H1N1) virus from intubated patients?

Introduction: In March 2010, more than 213 countries worldwide reported laboratory confirmed cases of influenza H1N1 infections with at least 16,813 deaths. In some countries, roughly 10 to 30% of the hospitalized patients were admitted to the ICU and up to 70% of those required mechanical ventilation. The question now arises whether breathing system filters can prevent virus particles from an infected patient from entering the breathing system and passing through the ventilator into the ambient air.We tested the filters routinely used in our institution for their removal efficacy and efficiency for the influenza virus A H1N1 (A/PR/8/34).Methods: Laboratory investigation of three filters (PALL Ultipor^® 25, Ultipor^® 100 and Pall BB50T Breathing Circuit Filter, manufactured by Pall Life Sciences) using a monodispersed aerosol of human influenza A (H1N1) virus in an air stream model with virus particles quantified as cytopathic effects in cultured canine kidney cells (MDCK). Results: The initial viral load of 7.74±0.27 log₁₀ was reduced to a viral load of ≤2.43 log₁₀, behind the filter. This represents a viral filtration efficiency of ≥99.9995%. Conclusion: The three tested filters retained the virus input, indicating that their use in the breathing systems of intubated and mechanically ventilated patients can reduce the risk of spreading the virus to the breathing system and the ambient air.     

甲钴胺的引湿性探讨

目的：了解甲钴胺的引湿特性,探讨化学对照品使用和贮存中应注意的问题。方法：采用动态水分吸附分析技术（DVS）研究甲钴胺在不同湿度条件下吸收水分的趋势和程度,以容量滴定法测定其水分的均匀性。结果：甲钴胺具有引湿性,且在一定湿度条件下吸水后仍具有较强的引湿性。结论：本研究为确定甲钴胺适宜的分装条件、包装用瓶和使用方式等提供了数据支持和参考依据。     

楤木皂苷胶囊成型工艺辅料筛选

目的:优选楤木皂苷胶囊的成型工艺辅料。方法:以颗粒的成型合格率、吸湿百分率、休止角和堆密度为评价指标,在逐一单个筛选辅料的基础上,筛选出适合制备楤木皂苷胶囊的混合辅料,并考察临界相对湿度(CRH)。结果:微晶纤维素-乳糖(1:1,m/m)混合辅料制成的颗粒抗潮性能强,流动性好。CRH为78%。结论:所选辅料可用于制备楤木皂苷胶囊。     

速释固体制剂主要辅料的流动性和吸水性测定

目的：了解速释固体制剂所用辅料的流动性和吸水特性，为粉末直接压片方法提供工艺参数。方法：采用粉末基础物性测定仪和吸水装置测定稀释剂的休止角、抹角、稀释剂的流动性指数和崩解剂的吸水速率常数。结果：国产微晶纤维素凝聚现象较强，流动性指数最小；进口微晶纤维素几乎没有凝聚现象，流动性指数最高。交联聚乙烯吡咯烷酮(PVPP XL)的吸水量最小，而吸水速率最快。结论：Avicel PH102微晶纤维素和40～80目乳糖作为主要稀释剂可用于粉末直接压片工艺。PVPP XL是一种优良的超级崩解剂。     

海藻酸微囊的制备与评价

目的:探讨利用气体雾化技术(AAT)制备的脂溶性药物吲哚美辛和水溶性药物对乙酰氨基酚海藻酸微囊的理化特性.方法:采用筛分法测定微囊粒径,紫外分光光度法测定微囊的包封率及载药量,恒重法测定微囊中的含水量.结果:海藻酸钠浓度增加、输送速度增加和氮气压力增加与微囊粒径减小.微囊的包封率和载药量随着药物溶解度的增加而降低.微囊含水量最初随着冷冻干燥时间的延长急剧下降,当下降到一定程度后随着冷冻干燥时间的延长变化不大.结论:采用AAT方法制备海藻酸微囊方法简单,但是水溶性大的药物不宜用此法制备微囊.     

Correlation and Prediction of Moisture-Mediated Dissolution Stability for Benazepril Hydrochloride Tablets

PURPOSE: This report investigated dissolution stability of benazepril hydrochloride tablets. METHODS: Reduction in dissolution rate was observed for benazepril hydrochloride tablets when they were subjected to stressed storage condition (40 degrees C/75% RH) for prolonged periods of time (1-3 months). Moisture contents of initial and stressed tablets were measured by Karl Fischer method. Comparative thermal and physical characterizations of initial and stressed tablets were also performed. A mathematical model that was used to predict possible reduction in dissolution rate was proposed and validated using experimental data. RESULTS: It was found that there was a direct correlation between moisture content of benazepril hydrochloride tablets and their percentage of dissolution at 10 min. At moisture content below 3.5%, there were no significant changes in dissolution values. Beyond that point, however, a close to linear decrease in dissolution was observed as a function of increase in moisture content. Results from thermal and X-ray analysis have ruled out possible changes in drug substance. Other physical characterization, such as scanning electron microscope and mercury porosimetry measurements, revealed changes in core structure of stressed tablets vs. initial tablets. Based on results from these measurements, "preactivation" of disintegrant was identified as the mechanism for reduction in dissolution rate above critical moisture content. A simple physical model for moisture uptake of benazepril hydrochloride tablets was also proposed for predicting when, based on water vapor transmission and critical moisture content, dissolution rate will decline. CONCLUSIONS: Physical changes of tablets mediated by moisture were the main cause for reduction in dissolution. Inclusion of desiccant, although beneficial, cannot prevent reduction in dissolution completely. The simple physical model proposed in this report was found to be useful in predicting the dissolution stability of the dosage form.