Drinking Water - It is not covered by a compendial monograph but must comply with the quality attributes comparable regulations of the European Union or Japan. It may be derived from a variety of sources, including a public water utility, a private water supply (e.g., a well), or a combination of more than one of these sources.
Drinking Water may be used in the early stages of chemical synthesis and in the early stages of the cleaning of pharmaceutical manufacturing equipment. It is the prescribed source of feed water for the production of pharmaceutical water. As seasonal variations in the quality attributes of the drinking water supply can occur, processing steps in the production of pharmaceutical water must be designed for this characteristic.
Purified Water - It (see USP monograph) is used as an excipient in the production of official preparations;in pharmaceutical applications, such as cleaning of certain equipment; and in the preparation of some bulk pharmaceutical chemicals. It must meet the requirements for ionic and organic chemical purity and must be protected from microbial proliferation. It is prepared using Drinking Water as feed water and is purified using unit operations that include deionization, distillation, ion exchange, reverse osmosis, filtration or other suitable procedures. PW systems must be validated.
Purified Water systems that produce, store and circulate water under ambient conditions are susceptible to the establishment of tenacious biofilms of microorganisms, which can be the source of undesirable levels of viable microorganisms or endotoxins in the effluent water. These systems require frequent sanitization and microbiological monitoring to ensure water of appropriate microbiological quality at the points of use.
Sterile Purified Water - This is Purified Water that is packaged and rendered sterile. It is used in the preparation of nonparenteral compendial dosage forms where a sterile form of Purified Water is required.
Water for Injection - WFI (see USP monograph) is an excipient in the production of injections and for use in pharmaceutical applications, such as cleaning of certain equipment and preparation of some bulk pharmaceutical chemicals. The source or feed water for this article is Drinking Water, which may have been preliminarily purified but which is finally subjected to distillation or reverse osmosis. It must meet all the chemical requirements for Purified Water and in addition the requirements under Bacterial Endotoxins Test. It also must be protected from microbial contamination. The system used to produce, store and distribute Water for Injection must be designed to prevent microbial contamination and the formation of microbial endotoxins and it must be validated.
Sterile Water for Injection - Sterile Water for Injection (see USP monograph) is Water for Injection that is packaged and rendered sterile. Sterile WFI is intended for extemporaneous prescription compounding and is distributed in sterile units. It is used as a diluent for parenteral products. It is packaged in single-dose containers not larger than 1Lin size.
Bacteriostatic Water for Injection - Bacteriostatic WFI (see USP monograph)is sterile Water for Injection which has added one or more suitable antimicrobial preservatives. It is intended to be used as a diluent in the preparation of parenteral products. It may be packaged in single-dose or multiple-dose containers not larger than 30mL.
Sterile Water for Irrigation - It (see USP monograph) is Water for Injection, packaged in single-dose containers larger than 1L, that is intended to be delivered rapidly and is rendered sterile. It need not meet the requirement for small-volume injections under Particulate Matter.
Sterile Water for Inhalation - It (see USP monograph) is Water for Injection that is packaged and rendered sterile and is intended for use in inhalators and in the preparation of inhalation solutions.
The author is an experienced pharmaceutical blogger.