WFI Ph. Eur. aus Membranverfahren
Die überarbeitete Monografie: Wasser für Injektionszwecke (0169) – Ph. Eur. Supplement 9.1
Originale
Key Words Wasser für Injektionszwecke (WFI) | Hochgereinigtes Wasser (HPW) | Requalifizierung | Destillation | Umkehrosmose (Reverse Osmosis – RO) | Ultrafiltration (UF)
Abstract
WFI Ph. Eur. Produced by Membrane Technology. The Revised Monograph: Water for Injection (0169) – Ph. Eur. Supplement 9.1
Over the last years, experiences made with the water quality grade „Highly Purified Water“ (HPW) show reliable results of the quality Water for Injection (WFI) produced by Reverse Osmosis. Nevertheless, in cold producing purification systems (15–25 °C), there is a potential risk of biofilm formation and endotoxins. Even by taking into account possible design failures, malfunctions or lacks of microbiological and hygienic knowledge of external service technician, the risk is significantly lower in hot WFI producing evaporation systems. Therefore, the need of a valid system layout, a decent hygienic design, and reliable maintenance services become essential in cold producing systems. Ultrafiltration (UF) is to be considered the final processing step and last barrier for microorganisms and endotoxins in cold producing water purification systems. In the event of biofilm formation on the resin of the electrodeionization (EDI) system, the UF serves as a protective barrier. As a consequence, innovations for proper and valid integrity testing and endotoxin challenge tests are expected to be developed by the supplying industry of UF modules. Without any doubt, the advantages of the established and approved hot WFI generation and distribution system will definitely accompany the industry for a long time.
As a matter of fact, the USP allows the generation of WFI by membranes for years. However, this is of no significant relevance in the USA. As a result, the industry absolutely welcomes the possibility to produce WFI by membranes given by the recent Annex 1 as a reliable system is used at reduced costs and a lower energy level. Expected updates and additional regulations by the revision of the EU GMP Annex 1 have to be considered.
Korrespondenz:
Hans-Hermann Letzner, Letzner Pharmawasseraufbereitung GmbH, Robert-Koch-Str. 1, 42499 Hückeswagen, Germany; e-mail: Hans-Hermann.Letzner@letzner.de
Zusammenfassung
Die langjährigen Erfahrungen mit der Wasserqualität „Highly Purified Water“ (HPW) zeigen, dass mit Membranverfahren zuverlässig die Wasser-für-Injektionszwecke(WFI)-Qualität erzeugt werden kann. Dennoch, das Risiko „kalter“ (15–25 °C) Wasseraufbereitungsanlagen geht von Biofilmen, Leitkeimen und Endotoxinen aus. Im Vergleich hierzu ist das Risiko bei heiß betriebenen
