Dissolution filters are used when samples are taken to prevent particles of tablet from getting into the sample and affecting the spectrophotometer or HPLC results.
- Cannula Filters - used when high levels of particulate are present
- Filter Discs - Low volume sample probes may require an In-Line Filter Disc. These are designed to keep the filtration process outside the vessel.
- Filter Tips - smaller than cannula filters, filter tips fit on the end of larger diameter sample probes.
Poroplast is the brand name of a specific UHMW Polyethylene. It is essentially the same as all the Polyethylene filters used in dissolution, but sometimes the filters are referred to by this name.
Selecting a Filter
It is recommended to ensure that your filters do not absorb any compounds of interest. Most filters are made from HMWPE but if this causes an issue then other materials are available such as PVDF. It is often possible to use a syringe filter that sits outside the media if the application requires it.
Caleva tablet dissolution baths normally use cannula style filters with a large range of porosities.