System design for purified water and water for injection
14 November 2013
Author: Hugh Hodkinson, lead process engineer, DPS Engineering
Purified water (PUW) and water for injection (WFI) are the lifeblood of pharmaceutical facilities. They are rarely given the same level of attention as the process equipment that makes pharmaceutical products, but any problem with the PUW or WFI systems has the potential to bring an entire facility to a standstill.
In a lecture given at Engineers Ireland HQ in Dublin, organised by the Chemical and Process Engineering Division, Hugh Hodkinson explains what PUW and WFI are, what their origins are and why they are so important to pharmaceutical production.
Hugh Hodkinson, lead process engineer with DPS Engineering, has over 12 years’ experience in the pharmaceutical industry. He has worked on design, construction and commissioning projects in several different countries. His areas of particular expertise are clean utilities and fill finish facilities.
“One key thing in pharmaceuticals is that you have to have a reproducible process,” he said. “With the water that comes out of the tap, it will be different today than it is in three months’ time. Whereas with purified water or WFI, there are very tight criteria as to what the content of that water is or the maximum level of various types of impurities,” Hodkinson added.
He describes in great detail the differences between them and how each is made for the purpose of being used in pharmaceutical facilities.
As Hodkinson points out, PUW is largely used in the manufacture of drugs that are not injected into patients, while WFI would typically be used in this particular manufacturing area. In addition, PUW would be used for the initial cleaning process, while WFI would be introduced for the final rinsing stages.
“Typically, you’d use WFI if you were making an injectable drug. You’d use WFI to bulk it up. Or if you have a process like a bioreactor or fermenter, again you’d use WFI because you don’t want to have extraneous bacteria or microorganisms that could overrun the process you’re running,” said Hodkinson.
He goes on to explain the various elements of water that are monitored in the production of WFI, such as aerobic bacteria. When consumed in drinking water, we have become resilient to these tiny organisms, but when it is injected into someone, it bypasses many of the body’s natural defences.
There are a number of equipment providers who will fabricate a PUW or WFI generation system, but that is only the first part of the puzzle. An equally complex part of the engineering process is to design a system that can maintain the water purity and deliver it to a myriad of different users throughout the facility, without compromising the quality.
Hodkinson explains the fundamental principles that apply to all designs, including ensuring the PUW or WFI is kept moving to prevent stagnation, regular sanitation and maintaining a sealed system with adequate filters. He goes on to walk the audience through the designs that he feels are most effective.
To view the full presentation, please click the link below.
|Purified Water and Water for Injection System Design|
|Date: Wednesday, 19 October 2011Category: Chemical and ProcessFiles: w-20120425-ipv6pow.arf (Download)|
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