Measurements with controlled humidity
The TGA-Sorption System is designed to analyze materials under defined conditions of temperature and relative humidity (RH).
The design concept combines the performance and versatility of the large furnace TGA/DSC 1 or TGA/SDTA85xe thermobalance with a unique interface approach that allows a humidity generator to be connected via a transfer line within a few minutes.
Measurements at controlled relative humidity provide information that is crucial for understanding the effects that moisture content can have on the properties of a wide range of materials:
- Processing – spray-dried powder that becomes moist can potentially block production equipment
- Product shelf life – can be shortened by moisture uptake due to inadequate packaging
- Structural properties – moisture content can reduce bioavailability and influence the therapeutic effect
Dynamic sorption curve
The TGA curve shows the uptake and release of moisture by a sample of amiloride hydrochloride dihydrate as a function of relative humidity (RH). The stages of the analysis include:
At a RH of about 50%, the substance has regained its original water of crystallization. Further increase of RH results in the uptake of free surface water. This is liberated when the RH is reduced.