Pharmaceutical grade water is defined as feed water common to process systems such as washers, autoclaves or WFI systems. Since water source varies widely in quality, only appropriate filtration systems can ensure the production to be effective, safe and successful.
Filtration is just one step of the manufacturing process of pharmaceutical grade water. Other steps may result in the increasing of particles, for both resin and activated carbon beds could produce powder.

Separation Goals

Prefiltration

● Remove colloidal and particulate contaminants to extend the service life of final filters.

Final Filtration
● Remove particles, microorganisms and endotoxins to meet the requirements of FDA and other international standards.

Application Requirements
● Prefilters must remove most particulate and colloidal contaminants effectively, and have high dirt-holding capacity, and keep high flow rates and high throughputs.
● Final filters must remove microorganisms and endotoxins, and keep high flow rates and high throughputs.

Recommendation

Filters with positive charge have limited capacity of removing endotoxins. Once the capacity is saturated, they lose this ability of removing endotoxins. Series connection of two filters is the solution, monitoring the endotoxins between the two filters. When endotoxins exist in the downstream of the first filter, the second filter should replace the first one in its position. This can make full use of filters and ensure reliable retention rate. Replacement of filters with no charge depends on pre-setting limitation index such as maximum differential pressure, minimum flow rate and maximum life time.