Privatsphäre-Einstellungen

F_o-Konzept bei Dampfsterilisationsverfahren und damit verbundene Sterilisationssicherheit

Michael Pfeiffer

Boehringer Ingelheim Pharma KG, Ingelheim/Rhein

F₀-Concept in Steam Sterilisation and the Connected Sterilisation Safety

The European Pharmacopoeia (Ph.Eur.) [1] requires in chapter 5.1.1 (methods of preparation of sterile products) for steam sterilisation that the products to be sterilised are to be heated at a minimum of 121°C for 15 min (= reference sterilisation procedure). Other combinations of time and temperature may be used provided that a sterility assurance level (SAL) of 10^-6 or less will be achieved; guidance concerning validation by means of the F_o-concept is given. The F_o-concept is regarded to be an equivalent sterilisation method; these are methods that yield with combinations of temperature and time different from those of the reference sterilisation procedure comparable lethal effects. The equivalent methods have the advantage that sterilisation temperatures of T < 121 °C might be more suitable for temperature labile products and are able to deliver comparable lethal effects when the necessary sterilisation times are adequately prolonged [2].
The F_o-concept of the Ph.Eur. is based on the assumption of a germ-specific z-value of 10^oC (definitions of z- and D-value: see chapter 2.). The real z-values of the biological indicator organism, being mentioned in the Ph.Eur. for monitoring steam sterilisation, spores of Bacillus stearothermophilus, lies in the range of 6-8 °C rather than 10 °C [2, 3, 4 and 5]. It lies in the mathematical nature of the F_o-concept that with z-values below 10^oC and sterilisation temperatures < 121 °C lethal effects far below those of equivalent times and sterilisation temperatures but with z-values of 10 °C occur. Consequently, the content of the chapter on the F_o-concept of the Ph.Eur. should be reevaluated by the pharmacopoeial commission, or, if the content remains unaltered, the users of the F_o-concept shall adopt the necessary sterilisation times at certain temperatures to the real z-values of Bacillus stearother-mophilus, in other words, the necessary sterilisation times have to be prolonged.

Key Words Dampfsterilisation · F_o-Konzept · Sterilisationssicherheit