[A comparison of the assay regulations for sterility testing between the USP XIX and the European Pharmacopoeia (author's transl)].

The USP XIX is to be published in the summer 1975. In this paper the most important passages of its sterility test are compared with the regulations of the EP 1. So a test should be rendered possible to come up to both Pharmacopoeia. a) Both the membrane filtration method and the direct inoculation of media may be used as the test methods. The membrane filtration method is the method of choice. But the mentioned pore diameter of 0.45 +/- 0.02 mum is too large. Those filters with a pore diameter of 0.2 +/- 0.02 mum are preferable. b) While EP 1 does not mention the culture media, USP XIX prescribes Fluid Thioglycollate Medium and Soybean-Casein Digest Medium. These culture media are not sufficient. The use of Fluid Thioglycollate Medium, Soybean-Casein Digest Medium and Fluid Sabouraud Medium is suggested. c) The same organisms are recommended for the control of the culture medium as well as for the determination of the minimal inhibiton concentration (Clostridium sporogenes, Bacillus subtilis, Staphylococcus aureus, Candida albicans and perhaps a mould fungus). d) In the USP the number of samples is decided by the risk of contamination. This is preferable to the EP 1, where the number of samples is fixed by the size of the charge. e) While EP 1 lays down 7 days as an incubation time for bacteria as well as fungi, the USP XIX prescribes a time between 7 and 14 days, depending on the contamination risk and on the method used. As a compromise 10 days for bacteria and 14 days for fungi are recommended.