Skip to main content
Login | Suomeksi | På svenska | In English

Browsing by Subject "rheological properties"

Sort by: Order: Results:

  • Neuvonen, Janina (2019)
    Flowability of powders is in critical role when manufacturing the most popular dosage forms, tablets and capsules, of pharmaceutical industry. Re-formulation is expensive and time-consuming, so it is important to determine powder flow properties at the initial stage of drug development prior to tabletting and encapsulation processes. There are many different methods, like shear cell, flow through an orifice and bulk and tapped density, to examine powder flowability. Despite the methods, the most reliable means of examining powder flowability is often empirical. In early stages of drug development, it would be good to have faster, more reliable and cheaper methods to examine powder flowability. FT4 Powder Rheometer is a relatively new flowability characterization technique. The aim of this study is to find out whether the library created using the FT4 Powder Rheometer methods makes it possible to characterize the rheological properties of solids in the early stages of drug development. In addition, the aim is to investigate whether FT4 Powder Rheometer methods can predict the success of masses in tableting and encapsulation processes. The information gained from the research can be used in the future, for example, in continuous processes, because flowability plays an important role, especially in the supply of raw materials to the process, which is the most important division of continuous processes. To the library were selected for particle size and shape 15 different types of material. These materials were subjected to five different FT4 Powder Rheometer basic test methods. In addition, the particle size and shape of the materials and the flow through an orifice and the bulk and tapped density were determined to support the results of the powder rheometer. The principal component analysis was used to process the results. As the tablet and capsule masses examined, the masses of a previous study were utilized. Those masses were tableted and encapsulated in that previous study. These tablet and capsule masses contain a variable amount of cohesive drug substance. FT4 Powder Rheometer methods provide more complex information about materials and their behaviour than conventional flowability test methods. From the powder rheometer parameters pressure drop, compressibility and specific energy distinguish the cohesive and the non-cohesive materials, because the cohesive materials with these parameters obtain clearly higher values than non-cohesive materials. Additionally, the cohesion of FT4 Powder Rheometer shear cell test mainly distinguishes highly cohesive materials from other materials. The flow rate index makes it possible to separate the materials to which the change in flow rate particularly affects. Fluidizing materials, due to the air flow, are distinguished by the aeration test. Avicel PH-102 could be used as a rough limit value for well and poorly flowing materials in the created library (excluding the aeration and shear cell test). Stability index -, flow rate index -, specific energy -, pressure drop -, and compressibility-results of the FT4 Powder Rheometer correlated to the proportional proportion of the cohesive drug in the mixture. These parameters could possibly be used to distinguish mixtures containing the cohesive material. Additionally, specific energy, compressibility, pressure drop, basic flowability energy, stability index and flow rate index correlated with the weight variation of the tablets. With these parameters one could possibly assess the tabletability of the mixtures. A much larger library is needed to evaluate and predict the rheological properties of new materials. FT4 Powder Rheometer can possibly be used to predict the tableting success of tablet and capsule masses. This would be interesting to look more extensively, for example as part of a library. Additionally, it would be good to investigate whether the results of powder rheometer correlate to continuous production.