Articles
RSSApplication Of 0.1 µm Filtration For Enhanced Sterility Assurance In Pharmaceutical Filling Operations
August 25, 2004
Introduction
0.2 µm and 0.22 µm rated filters are widely used in the terminal sterilization of pharmaceutical products. The rating of "0.2 µm" and "0.22 µm" implies that this is the actual pore size of the membrane. Is this a realistic representation of the actual situation? Do such filters automatically provide a guarantee of sterility?
0.2 µm and 0.22 µm rated filters are widely used in the terminal sterilization of pharmaceutical products. The rating of "0.2 µm" and "0.22 µm" implies that this is the actual pore size of the membrane. Is this a realistic representation of the actual situation? Do such filters automatically provide a guarantee of sterility?
Physical Properties of 0.2 µm and 0.22 µm Rated Filters
One of the longest established methods for determining the pore size of porous structures, including membranes, is the bubble
point test. As represented in Figure 1, the test measures the gas pressure needed to displace liquid from the pores of a wetted
micro- porous structure. The bubble point test can provide an accurate measurement of pore diameter for a structure containing
perfectly cylindrical pores. If the bubble point pressure were measured for a 0.2 µm or 0.22 µm rated membrane containing this
type of pore structure, the result measured would be in the range of 13 bar (189 psi).
