Water for Inhjection (WFI) in Pharma More Flexibility for Pharma: Why WFI is About to Unleash its True Potential

Author / Editor: Andreas Minzenmay* / Dominik Stephan

The change in European Pharmacopoeia (Eur. Ph.) gives more flexibility to the operators of WFI systems — The release of the membrane process for the production of Water for Injection purposes (WFI) in European pharmacopoeia (Eur. Ph.) opens up annual savings potential for pharma enterprises up to several hundred thousand Euro, at min. the same or higher water quality. The article illustrates what exactly was changed and why in Eur. Ph., what effects the change will have in practical terms and what a good plant for cold WFI production must look like.

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More freedom for operators with the new WFI monograph.
More freedom for operators with the new WFI monograph.
( © Lukas Gojda - Fotolia)

Worldwide, the different specification of purest water supply are an impediment to globalised markets. The requirements of WFI and its manufacture are prescribed in the monograph Water for Injections (0169) in the European pharmacopoeia (Eur. Ph.). Unlike the United States Pharmacopoeia (USP) and the Japanese Pharmacopoeia (JP), it prescribed distillation as the only permissible process.

The USP from 2003 and the JP since the 80s also prescribe other methods besides distillation. Nevertheless, at present, WFI is still produced worldwide by and large through distillation, although it is a very expensive process in view of the investment and operation costs. Pharmacy enterprises emphasise that this is interconnected partly to the fact that their plants manufacture bulk products for different continents or are used as backup and therefore, must conform to all pharmacopoeia.

How to Stop the Bio-Film Formation

Thanks to the change in Ph. Eur., operators will be able to select and use other methods, and thus reduce their costs significantly from April 2017 on. The road to the revised version of the European WFI monograph was a long one by all means. It was discussed and deliberated for many years whether the membrane process yields comparable quality and at the same time, a high degree of safety as distillation.

In membrane systems, one fears the creation of a bio-film and therefore contamination of the water with micro-organisms and their degradation products. In practice however, monitoring data of Highly Purified Water (HPW) plants prove that membrane systems fall well below the specifications of WFI and satisfy them fully.

In the plants, Reverse Osmosis (RO) is also not the final stage; there are further treatments like electrode ionization (EDI) and ultra-filtration (UF). The microbiological safety of the systems is achieved through several complementing and coordinated steps, consistent monitoring, meaningful operation and sanitization as well as intelligent construction and component selection.

The Future of Purest Media Systems

The water quality specifications in the semi-conductor industry are conspicuously more stringent than in WFI: There, the water is manufactured safely and reliably in large quantities with multi-stage cold processes like RO, EDI and UF.

After a year–long evaluation process, the revised WFI monograph 0169 will become legally effective from April 2017. The scope of adjustments made in the revision is very transparent, yet the consequences for the design of future purest media systems are enormous.