by Richard Priest | Sep 12, 2021
The so-called blow-through theory, when organisms supposedly are pushed through a membrane by elevated pressure has yet to be proven. It has been determined that organisms like mycoplasma can be pushed through a membrane at elevated pressures, but typically one would...
by Richard Priest | Sep 12, 2021
Yes, the filter requires to be fully wetted with product to perform the PUPSIT accurately. After the PUPSIT it would be advisable to flush the filter with product, as one does not know what happened to the product within the filter matrix during the test time of the...
by Richard Priest | Sep 12, 2021
Typically, the filter integrity test is an automated test, which does not necessarily reduce the risk, as downstream manipulation requires to be performed also with an automated test device. To divert the wetting fluid, vent the downstream filtrate side, potentially...
by Richard Priest | Sep 12, 2021
Filters that are steam sterilized in-situ do not need to be flushed as the steam would flush out any potential leachables. Gamma sterilized system may need to be flushed with a small portion of the product if the first milliliter going directly into a vial. This would...
by Richard Priest | Sep 12, 2021
Any precipitation creates a higher fouling fluid, as seen in the past with animal-derived serum, which typically had precipitates and fouled filters rapidly. So, when proteins precipitate the fouling rate is typically higher.