Abstract Determination of residence time distribution is considered essential for continuous pharmaceutical unit operations, in order to enable process understanding and control. A common way for determining residence times are tracer based methods, yet at the moment most realizations are found in liquid systems whereas use of those methods on granular samples is rarely encountered. Here, we compare two different methods for applying and detecting tracers in granular material processed in a pharmaceutical capsule-filling unit. As first method, a simple colorimetric procedure, i.e. using a dye and a camera as photometer is used. As second method, light induced fluorescence, i.e. using a fluorescent tracer material, a stimulating source and the camera as photometer again, is used. Both methods are tested and compared for their performance and appeared to be sufficient for the use in residence time distribution determination, yet none of the two proved to be superior. Consequently, side issues rather than analytic performance determined the final preference for the colorimetric method.

中文翻译：

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LIF 或染料：颗粒固体不同示踪方法的比较

摘要 停留时间分布的测定被认为是连续制药单元操作必不可少的，以便能够理解和控制过程。确定停留时间的常用方法是基于示踪剂的方法，但目前大多数实现是在液体系统中找到的，而很少遇到在颗粒样品上使用这些方法的情况。在这里，我们比较了在药物胶囊填充装置中加工的颗粒材料中应用和检测示踪剂的两种不同方法。作为第一种方法，使用简单的比色程序，即使用染料和照相机作为光度计。作为第二种方法，使用光诱导荧光，即再次使用荧光示踪材料、刺激源和照相机作为光度计。测试和比较了这两种方法的性能，似乎足以用于确定停留时间分布，但没有一种方法被证明是优越的。因此，决定了比色方法的最终偏好的是附带问题而不是分析性能。