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Applications of temperature modulated differential scanning calorimetry in freeze-drying process development.

机译：温度调制差示扫描量热法在冷冻干燥工艺开发中的应用。

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摘要

The purpose of the present study was to investigate the potential of Temperature Modulated Differential Scanning Calorimetry (TMDSC) as an analytical tool in freeze-drying process development. After developing an adequate calibration method, the frequency dependence of low temperature transitions in model solutions was probed in an effort to support physical interpretations of the events that are observed in concentrated solutions. This information is useful both for the understanding of macroscopic collapse in vials and microscopically observed collapse during freeze-drying. Using sucrose solutions as the model system, a low temperature transition was found to possess frequency dependent characteristics consistent with a glass transition. A slightly higher temperature transition was found to possess frequency characteristics consistent with a melting event. Quasi-isothermal heat capacity data for sucrose solutions demonstrated kinetically limited ice crystallization in the glass transition region.;A TMDSC method was used to determine the apparent partial derivative of the rate of ice crystallization as a function of temperature for model solutes. As further evidence for the interpretation of the higher temperature thermal event, a peak in the ice crystallization rate was observed at temperatures consistent with the warming curves. A novel approach to determining the limit of detectable ice crystallization, Tc,lim, in frozen systems was developed by locating an apparent minimum in the partial derivative of the ice crystallization rate. An advantage of the method is that the collapse temperature can be estimated even if the glass transition is not detected during warming.;Finally, the frequency dependence of the glass transition was used to determine the fragility of model systems of non-crystallizing solutes in water. Using a closed system model the microscopically measured collapse temperature was predicted from determinations of the reduced collapse temperature and the fragility parameter.
机译：本研究的目的是研究温度调制差示扫描量热法（TMDSC）作为冷冻干燥工艺开发中的分析工具的潜力。开发出适当的校准方法后，探索了模型溶液中低温转变的频率依赖性，以支持对浓缩溶液中观察到的事件进行物理解释。该信息对于理解小瓶中的宏观崩解和冷冻干燥过程中的微观观察崩解都是有用的。使用蔗糖溶液作为模型系统，发现低温转变具有与玻璃转变一致的频率依赖性特征。发现稍高的温度转变具有与熔化事件一致的频率特性。蔗糖溶液的准等温热容数据证明了在玻璃化转变区域中冰的动力学受限。; TMDSC方法用于确定模型溶质随温度的函数的表观偏微分。作为解释高温热事件的进一步证据，在与升温曲线一致的温度下观察到冰的结晶速率达到峰值。通过确定冰晶化速率的偏导数的表观最小值，开发了一种确定冷冻系统中可检测到的冰晶化极限的新方法。该方法的优点是，即使在加热过程中未检测到玻璃化转变，也可以估算出塌陷温度。最后，使用玻璃化转变的频率依赖性来确定水中非结晶溶质模型系统的脆弱性。 。使用封闭的系统模型，通过确定降低的塌陷温度和脆性参数可预测微观测量的塌陷温度。

著录项

  • 作者

    Knopp, Shawn Allen.;

  • 作者单位

    Purdue University.;

  • 授予单位 Purdue University.;
  • 学科 Chemistry Physical.;Health Sciences Pharmacy.
  • 学位 Ph.D.
  • 年度 1999
  • 页码 129 p.
  • 总页数 129
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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