Global Standards for Pharmaceutical Water Classification

Inquiry

Pharmaceutical water is widely used in the production of drugs, medical devices and the preparation of pharmaceutical preparations, as well as being used as a solvent, flushing agent, etc. The quality of water for injection can have a direct impact on the quality of pharmaceuticals and their safety. In this article, we outline the classification standards for pharmaceutical water in China, the U.S., the EU and Japan.

Pharmaceutical Water Classification in China

Pharmaceutical water in China is classified into potable water, purified water, water for injection and sterilized water for injection according to the scope of use. Potable water is the raw water for pharmaceutical water, and its quality must meet the current "Sanitary Standard for Potable Water".

Purified water, water for injection and sterilized water for injection in the ChP have each theory contained, and the quality should meet the requirements of the standard.

Purified water

Purified water is pharmaceutical water prepared from potable water by distillation, ion exchange, reverse osmosis and other methods.

Use of purified water:

As a solvent or test water for the preparation of common pharmaceutical preparations
As a solvent for extraction of drinking tablets used in sterilized preparations such as traditional Chinese medicine injections, eye drops, etc
Solvent or diluent for the preparation of oral and external preparations
Water for fine washing of instruments for non-sterile preparations
Used as a solvent for extraction of tablets used in non-sterile preparations

Water for injection

Water for injection is water obtained by distillation of purified water, and should meet the requirements of the bacterial endotoxin test. Water for injection can be used as a solvent or diluent for the preparation of injections, eye drops, etc., and the fine washing of containers.

Sterilized water for injection

Sterilized water for injection is water for injection prepared according to the production process of injection. Sterilized water for injection is mainly used as a solvent for sterilizing powder for injection or a diluent for injection.

Pharmaceutical Water Classification in the U.S.

Pharmaceutical water in USP can be divided into water with quality standards in the Pharmacopoeia and water without quality standards according to inclusion status.

Water of standard quality

Received quality standard water can be divided into bulk batch water (i.e., water produced in large quantities using a multi-unit operating system, piped, and ready for use), and packaged sterilized water.

Bulk water

Bulk water is divided into purified water, water for injection, dialysis water and pure steam. The minimum water source standard for the production of all four types of water is potable water.

Purified water is mainly used as excipients in the production of parenteral preparations and for cleaning certain equipment and contact parts of parenteral preparations
Water for injection is mainly used in the production of parenteral preparations and other preparations that require control of bacterial endotoxins, as well as for cleaning certain equipment and parts in contact with parenteral preparations
Water for dialysis is used for the production of hemodialysis products and the dilution of concentrated hemodialysis solutions
Pure steam or its condensed water can be used in the production, sterilization and final cleaning process of pharmacopoeia varieties to remove impurities and residues

Sterile water

Sterile water (packaged water) is the water that passes through the production, packaging and sterilization processes. Sterile water can be divided into sterilized purified water, sterilized water for injection, bacteriostatic water for injection, sterilized water for irrigation and sterilized water for inhalation.

Sterilized purified water is purified water that has been packaged and sterilized for use in the preparation of parenteral preparations or as purified water for analysis. Sterilized purified water is generally used when there is a lack of a validated purified water system and the amount needed is small
Sterilized water for injection is packaged and sterilized water for injection that can be used for immediate prescription dispensing and as a sterile diluent for parenteral preparations and other uses
Bacteriostatic water for injection is supplemented with one or more antimicrobial preservatives and can be used as a diluent for the preparation of injectable varieties, most commonly for multi-dose products requiring repeated extraction of the contents
Sterilized irrigation water is water for injection packaged and sterilized in single-dose containers and is sterile water that can be used for flushing
Sterilized inhalation water is packaged and sterilized water for injection. It is mainly used for inhalants and the preparation of inhalation solutions

Water without quality standards

In addition to the bulk and sterilized water mentioned above, water that is not loaded with standards in the monograph is also used in the pharmaceutical process. These waters are used in equipment cleaning, synthesis processes, further purification of raw materials and quality testing.

Pharmaceutical Water Classification in the EU

High purity water was established by the EP in 2002, which states that high purity water may be used in systems that do not require the use of water for injection for formulation, but where microbiological parameters in the water need to be tightly controlled. High purity water is used for eye drop solutions, otolaryngology solutions, dermatological pharmaceuticals, aerosols, initial rinsing of sterile product containers, and non-sterile APIs for injection. High purity water is prepared using a combination of reverse osmosis technology and technologies such as ultrafiltration or deionization.

In 2017, the EU began to allow the use of methods equivalent to distillation techniques for the production of water for injection and removed high purity water from the EP in 2019.

Current EP classification of pharmaceutical water:

Water for injection

Water for injection is used as an excipient to dissolve or dilute medicinal substances or to prepare preparations for the administration of drugs by injection. Water for injection includes bulk water for injection and sterilized water for injection.

Purified water

Purified water is not required to be sterile and depyrogenic, unless otherwise reasonably demonstrated and approved by other authorizations. Purified water that meets the requirements for endotoxin testing as described in EP monograph 0008 may be used in the production of dialysis solutions. Purified water is available as bulk purified water and packaged purified water.

Water for extract preparation

Water for extract preparation shall meet the requirements for purified water in bulk or in drums as described in monograph 0008, or shall be of comparable quality to that of water for human consumption as specified in Directive 98/83/C, and need to be monitored in accordance with the requirements under the Production section of the monograph. Specific requirements can be found in EP monograph 2249.

Pharmaceutical Water Classification in Japan

The classification of pharmaceutical water in JP is similar to that of ChP, with the addition of packaged purified water and packaged sterilized purified water. Except for potable water, which is subject to the Japanese Water Supply Law, the other five categories have their own standards.

Purified water removes microorganisms and impurities with a molecular weight of not less than 6000 by distillation, ion exchange, reverse osmosis, ultrafiltration and other methods
Packaged purified water is purified water filled into an airtight container
Packaged sterilized water is purified water that is filled into an airtight container and then sterilized or sterilized purified water that is filled into a sterilized container through aseptic operation
Water for injection is water specially treated (such as ion exchange or reverse osmosis) or purified water prepared by distillation, reverse osmosis or ultrafiltration
Packaged sterilized water for injection is water for injection prepared by a tanking and sterilization process

At Proregulations, we understand the importance of pharmaceutical water for drug research and development and production, and are dedicated to helping companies meet the requirements of regulations. Contact us and let us assist you in ensuring the safety, compliance and quality of pharmaceutical water.