The Journey of Water for Injection (WFI) - Ensuring Purity in Every Drop

Water might seem simple, but when it comes to injectable medications, purity is critical. Water for Injection (WFI) is a specially purified form of water that plays a vital role in the preparation of life-saving medications. It’s not just any water—it’s one of the highest quality grades, undergoing a meticulous purification process to ensure that it’s free from bacteria, endotoxins, and all contaminants.

At Selkirk Pharma, we pride ourselves on our state-of-the-art water purification system, which ensures every drop of WFI meets the highest industry standards. Our Reverse Osmosis system is designed to generate compendial water that meets the strict guidelines set by the USP, EP, and JP—the benchmarks for pharmaceutical manufacturing. Our system is equipped with a fully programmable logic control (PLC) that allows us to produce WFI on demand, keeping our operations running smoothly and efficiently.

The Source of Pure Water: The Spokane Aquifer

The journey of WFI begins with the Spokane Aquifer, a natural source of water that plays a crucial role in ensuring the quality of our products. Here’s why this aquifer is so special:

1. Natural Purity: The Spokane Aquifer provides water with naturally low contaminant levels. As it flows through layers of sand, gravel, and other natural filters, the water undergoes a process of natural purification that helps maintain its pristine quality.
2. A Sole Source of Water: The U.S. Environmental Protection Agency (EPA) has designated the Spokane Aquifer as a Sole Source Aquifer, meaning it is the region’s primary source of drinking water. This distinction ensures that it’s safeguarded from significant contamination, giving us peace of mind knowing we start with such a pure resource.
3. Reliability: The aquifer is not only clean but also incredibly reliable. Its highly productive nature means it consistently delivers water in the volumes we need, which is essential for producing WFI at scale.
4. Advanced Treatment: Spokane’s advanced water treatment facilities ensure that the water we receive meets the highest standards, setting us up for success at every step of the process.

From Aquifer to Injectable: Our WFI Production Process

Once we’ve sourced the water, the journey to transforming it into Water for Injection is a complex and fascinating process. Here’s how it works:

1. Initial Treatment: The water begins its journey by being pre-treated through an ion-exchange water softener, which removes excess calcium, followed by an activated carbon filter to eliminate chlorine. At this stage, the water is already well on its way to becoming pure.
2. UV Disinfection: To ensure that harmful microorganisms are neutralized, the water passes through Ultraviolet (UV) light. UV technology works by inactivating the DNA of these microorganisms, making it impossible for them to reproduce.
3. Reverse Osmosis (RO): The heart of our purification process. In a 2-pass Reverse Osmosis system, water is forced through a semi-permeable membrane to remove organic and inorganic contaminants. This step is critical in making sure the water is as pure as it can be.
4. Electrodeionization (CEDI): Next, CEDI further purifies the water by removing ionized species, ensuring the water’s conductivity is lowered to the exact levels required for WFI.
5. Ultrafiltration (UF): We then run the water through a filtration step that removes particles, organics, microbes, pyrogens, and other contaminants that are too large to pass through the membrane (over 6,000 Daltons). This ensures the highest level of purity.
6. Heat me up Scottie: Before entering our distribution system, the WFI is heated to 80°C to ensure its safety and sterility.
7. Continuous Distribution: Our purified WFI distribution system stores 1200 gallons of WFI and maintains it at 80°C and is pumped in a continuous loop throughout the facility to reduce bacterial colonization. It is now ready to be used on demand for our pharmaceutical production processes.

The Importance of WFI

Each step in this process matters, ensuring that the water we produce is not only pure but also reliable. For injectable manufacturing, there is no room for error. Every drop of WFI used in our facility has been carefully treated, tested, and stored to meet the highest standards of quality. And that’s something we don’t take lightly.

Additional Resources

Water for Pharmaceutical Use | FDA

General Chapters: <1231> WATER FOR PHARMACEUTICAL PURPOSES | USP

Quality of water for pharmaceutical use - Scientific guideline | European Medicines Agency (EMA)

The Spokane aquifer, Washington: its geologic origin and water-bearing and water-quality characteristics | U.S. Geological Survey

About Selkirk Pharma

Selkirk Pharma (www.selkirkpharma.com) is a world-class sterile fill/finish CMO in Spokane, Washington, USA. We are a key partner for companies that need a partner with a reliable, high-yield, US-based contract manufacturing organization (CMO). Selkirk Pharma was purpose-built by fill/finish industry veterans for on-time, in-full, sterile fill/finish GMP manufacturing of injectable drug products. You can count on our industry-leading processes, technologies, and support that reduce production bottlenecks, address product shortages, and onshore pharmaceutical manufacturing. Selkirk’s promise is the reliable delivery of your high-quality products. We offer best-in-class liquid vial filling in our Bausch + Ströbel VarioSys^® fill line. We offer full Analytical and microbial services.

Want to learn more, visit our website at www.selkirkpharma.com, Virtually tour our facility, or reach out to our BD team at bd@selkirkpharma.com

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