Types of Water in Pharmaceutical Industry

Water is the most widely used raw material in pharmaceutical manufacturing, but did you know that different grades of water have strict regulations based on their intended use? Using the wrong type of water can lead to product failures, contamination risks, and regulatory non-compliance.

Drinking (Potable) Water

Used as a feed water source for pharmaceutical-grade water systems.
Must meet WHO, BIS, US EPA (40 CFR 141) or local potable water standards.
Microbial limit: ≤500 CFU/mL (varies by region, not specified in all standards).

Purified Water (PW)

Used in non-parenteral formulations and for cleaning equipment.
Produced via reverse osmosis, deionization, or distillation.
Microbial limit: ≤100 CFU/mL (per USP, Ph. Eur., IP).
Not for direct IV use—must be further processed for injectables.

Water for Injection (WFI)

Used in parenteral formulations and as a cleaning agent.
Produced by distillation (preferred) or equivalent methods (Ph. Eur. allows RO + ultrafiltration).
Stored at ≥80°C (hot loop) or 2-8°C (cold loop) with microbial control.
Microbial limit: ≤10 CFU/100 mL & endotoxin limit: ≤0.25 EU/mL.
No official pharmacopoeial pH specification.

Sterile Water for Injection (SWFI)

WFI that has been sterilized and packaged in single-dose containers (≤1L).
Used as a diluent for injectable drugs, but NOT for direct IV infusion unless made isotonic.

Bacteriostatic Water for Injection (BWFI)

Contains antimicrobial preservatives (e.g., benzyl alcohol).
Used for multi-dose drug dilution.
NOT suitable for neonates due to toxicity risks from preservatives.

Water for Hemodialysis

Used to prepare hemodialysis solutions and must meet USP/Ph. Eur. monographs.
Endotoxin & microbial limits stricter than potable water due to direct blood contact.

Sterile Water for Irrigation