WATER FOR INJECTION (WFI) / MULTI COLUMN
A “water for injection (WFI) plant” is a system designed to produce ultra-pure, sterile water, known as WFI, for use in pharmaceutical manufacturing and medical applications, ensuring the water meets strict standards for injection safety.
Water for injection is water of extra high quality without significant contamination. Water for Injection (WFI) is sterile water used for the manufacturing of pharmaceutical products which are administered parenterally, ophthalmically, or inhaled. WFI also is used for cell culture growth media, washing, and rinsing bioreactors in fast-growing biologic therapies.
The water must go through a pre-filtration procedure that involves softening, dechlorination and deionization. During this stage, it also goes through reverse osmosis and UV disinfection. Once this is completed, it undergoes a distillation process. This is accomplished using either vapor compression or multiple effect distilling.
This procedure uses shell and tube heat exchangers (columns) to transfer heat via falling film evaporation. Each drop of water generated is heated to extremely high temperatures, ensuring the sterility requirements needed for WFI. The Pyrogenic load is separated using centrifugal forces created by the upward flow of the steam.
During the process, the feed and distilled water within the plant is constantly moving, so there is no stagnation. Impurities, together with the Pyrogenic load, are continually purged from the final column. The leftover collected water will be drained off during start-up during pre-heating and self-sanitization before WFI is created.
Systems producing WFI also need to undergo a validation process to ensure it is producing water that meets the required specifications in order to be used safely.
