Low temperature generation of HPW and WFI

The pharmaceutical industry fundamentally requires water in two levels of purity for production: Clean water in PW quality (Purified Water) and water for injection (WFI). The high WFI quality can be produced via technical methods using filtration or distillation processes. However, only distilled water is currently approved for injection purposes in Europe. Filtrated water of the same quality is therefore designated as “Highly Purified Water” (HPW).



The basic medium for this “cold” treatment technology is clean water in PW quality. The separating procedure with hollow fiber polysulphone membranes achieves a separation limit far below the size of bacteria, viruses and pyrogens. Ultrafiltration therefore delivers ultra pure water which, depending on regional regulations, satisfies the quality criteria for both HPW and WFI.


Vacuum membrane distillation

This new and patented technology is a highly efficient and robust process for distillation using a membrane for droplet separation. Thanks to this combination potable water can be directly processed to WFI quality without intermediate steps. The drinking water is first vaporized under vacuum conditions. Then the steam passes through a hydrophobic membrane which separates droplets. Suspended solids, dissolved organic materials, ions, bacteria and endotoxins are segregated during distillation. The process is continuously monitored by online measurements of TOC (Total Organic Carbon), pressure, temperature and conductivity. The multistage process provides a highly efficient heat recuperation while it operates at comparably low temperatures between 50 °C and 80 °C. The entire system can be sanitized periodically by means of heated water.


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With these technologies, Bosch provides two reliable procedures for manufacturing pharmaceutical water to WFI or HPW quality, which both display far greater energy efficiency and cost efficiency in comparison to classic high temperature distillation.


Klaus H. Schreiber
Marketing Responsible
phone: +49 (351) 28278-833

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