Relequa is a new application of water activity measurement designed to test equilibrium relative humidity (ERH) of tablets and capsules within high density polyethylene (HDPE) containers
Relequa has a built-in 30ml HDPE bottle with a small head space to allow rapid measurement of the internal \\\\\\\%RH and has a workable volume for handling samples of tablets and capsules.
Ideal as a first look for water activity, moisture sorption studies are easily performed by simply adding tablets or capsules and screwing on a cap.
The software has options for observing changes in the internal humidity in real time and downloading data.
Moisture sorption and desorption by the sample is continuous and after a period, determined by the activity of the sample, an equilibrium is established at its ERH.
Knowing the ERH is important in deciding if a material is likely to absorb or lose moisture at a given \\\\\\\%RH.
Based on the ERH of samples, manufacturing processing conditions can be determined to control processing and packing.
Typical other applications are testing the effectiveness of desiccants and the impact of temperature changes during sample shipment.
Tests using Relequa are simple and empirical requiring no calculations.
Relequa is compact and completely portable.
The test system is applicable for use both as an aid for in-process development and as a process analytical tool.
Relequa has been used to gain valuable information and insights into the behaviour of moisture in final and finished products exposed to different environmental circumstances.
