The EDQM has launched a survey on whether the test for oxidisable substances for sterilised water for injection in containers (Sterile WFI) in the European Pharmacopoeia (EP) should be changed to a total organic carbon (TOC) test. For WFI Bulk, the requirement of all relevant pharmacopoeias for TOC is 500 ppb.
The planned change is also being discussed with the United States Pharmacopeia (USP) and the Japanese Pharmacopoeia (JP). The USP is working on harmonising the monograph for sterile WFI with EP and JP, focusing on the test point TOC. The USP already replaced the test for oxidisable substances for sterilised WFI with a TOC test some years ago, but not with a limit of 500 ppb. The USP limit varies, starting at 8 ppm (ppm) and increasing depending on the volume of the container. This is because containers and the installation process can add TOC. Larger containers have lower TOC limits. Small dosage forms (e.g. water for reconstitution of an injection) have a higher TOC limit.
Now, before the EDQM launches the official consultation phase for the amendment of the monograph, they would like to gather information from the pharmaceutical industry to ensure that the method and acceptance criteria envisaged in the discussions with the partner pharmacopoeias are feasible for the European manufacturers of sterilised water in containers.
The survey consisting of 12 questions on the conversion of the test for oxidisable substances to TOC for sterilised water in containers can be found on the EDQM website.