Water and steam used in the pharmaceutical industry and related disciplines are classified by various pharmacopeias. The U.S. Pharmacopeia (USP) classifies compendial waters (Pharmaceutical Water) as follows:
- Water for Injection
- Bacteriostatic Water for Injection
- Sterile Water for Inhalation
- Sterile Water for Injection
- Sterile Water for Irrigation
- Purified Water
- Sterile Purified Water
- Water for Hemodialysis
- Pure Steam
- Drinking Water
With the exception of Drinking Water, USP Purified Water, USP Water for Injection, and USP Pure Steam, the classifications listed above refer to packaged water. Drinking Water, USP Purified Water, and USP Water for Injection are the primary waters used for most pharmaceutical applications, and are the primary topic of this book. Validation is required for all compendial water systems producing USP Purified Water or USP Water for Injection, with the exception of Drinking Water.
Drinking Water used in a specific application generally requires commissioning/qualification to an internal specification, verifying that the quality of the product water, from both a chemical and microbiological standpoint, does not vary from established internal specifications with time. This qualification process is often used not only to maintain control of product water but also to document the nature of the system by preparing and executing documents similar to those used for compendial water systems. Obviously, the internal specifications established for a qualified system may parallel a particular USP official monograph specification, such as that for Purified Water. Finally, certain applications may expand the USP requirements for a particular grade of water.
As an example, many biotechnology water specifications require low bacterial endotoxin Purified Water. For such application, the biotechnology company would validate the system as a USP Purified Water system and incorporate an internal bacterial endotoxin specification. Chemical, bacteria, bacterial endotoxin, and other parameters associated with each of the pharmaceutical grades of water identified above are addressed individually in further posts.
USP is prepared and published by The United States Pharmacopeial Convention. The material within USP is established by Expert Committees, circulated to the general public for comment and review, and revised after acceptance. The Expert Committees as well as the review processes include U.S. Food and Drug Administration comment, review, and approval. Since new volumes of USP are published periodically, it is suggested that reference to USP states the number of the most recent addition and/or most recent edition including all Supplements.