Manual Sampling for the „High Head“ versions of the ERWEKA Dissolution Testers is very simple due to the U-shape arrangement of the six Test Stations.
A special syringe with 90° needle is available from ERWEKA as accessory.
For the „Low Head“ versions manual sampling is even easier! Wide sampling openings (sealed by membranes against evaporation) in the Head of the unit allow sampling from all the up to 8 Test Stations by a pipette.
Automated Sampling in accordance with the latest USP specifications is available for the „Low Head“ versions of DT 720/820 and DT 700-2.
The essential point is that USP XXIV says that when for automation any part of the unit is modified (i.e. shaft, stirrer, tubes) the unit has to be cross-validated for each single product.
For this reason ERWEKA developed a sampling system which does nothing else than simulating the manual sampling process.
The sampling tubes are driven into the media only while sampling, not to cause changes of the hydrodynamic. In addition the sampling tubes are accurately moved to the USP sam-pling point, mid way between the surface of the media and the top of the stirrer or basket.
The second automated sampling system, also available for the „High Head“ versions is a system where the sample is taken through the hollow shaft of the stirrer. Please note that at this system the stirrer is modified and the sampling height can not be adjusted for all USP required heights. Cross-validation is needed to fulfil USP requirements!