Water for pharmaceutical use is classified according to how the pharmaceutical product is administered to the patient. They are regulated in the various pharmacopoeias (European Pharmacopoeia, United States Pharmacopoeia, Japanese Pharmacopoeia, etc.).

The types of pharmaceutical water are :
  1. Bulk forms :
    • Purified Water (PW)
    • Highly Purified Water (HPW) (European Pharmacopoeia)
    • Water For Injection (WFI)
    • Water For Hemodialysis
  2. Packaged Forms :
    • Bacteriostatic WFI
    • Sterile Water for Inhalation
    • Sterile Water for Injection
    • Sterile Water for Irrigation
    • Sterile Purified Water
Purified water 
  • Used as excipients in manufacturing of pharmaceuticals
  • Used for equipment cleaning esp. product contact surfaces of nonsterile chemicals
  • Preparation of bulk chemicals
  • Contains no added substance
  • Not for use in parenteral or sterile dosage
  • Prepared using potable water as feed
  • Type of purifications: Deionisation, distillation, Ion exchange, Reverse Osmosis, Filtration
  • Purified Water Quality Requirements :
    1. Conductivity: 3 stage measurement procedure
      No temperature compensation allowed
      Stage 1 online or lab test
      Stage 2 and 3 lab tests
    2. Total Organic Carbon: 500 ppb limit response
    3. Microbial Action Limit: 100 cfu / ml maximum - may be lower for specific process and product applications
    4. TOC < 500 ppb or oxidizable substance test
Water For Injection
  • Used ad excipient in manufacturing of potentials
  • Used for Equipment Cleaning esp.product contact surface of sterile products
  • Preparation of sterile bulk chemicals
  • Preparared using purified water as feed
  • Method of preparation is multicolumn distillation
  • Water for Injection Monograph Requirements :
    1. Meets all requirements for Purified Water
    2. Produced by "distillation or purification process proven to be equal to or superior to distillation"
    3. TOC < 500 ppb
    4. Conductivity < 1.1 uS/cm at 200 C
    5. Passes Bacterial Endotoxin test - not more than 0.25 EU/ml
    6. Microbial Action Limit: 10 cfu / 100 ml maximum - may be lower for specific process and product applications
Water for Hemodialysis
Water for Hemodialysis is water that complies with the US Environmental Protection Agency National Primary Drinking Water Regulations and that has been subjected to further treatment, using a suitable process, to reduce chemical and microbiological components. It is produced and used onsite under the direction of qualified personnel. It contains no added antimicrobials and is not intended for injection.

Bacteriostatic WFI : Contains added preservatives
  • Is a sterile, nonpyrogenic preparation of water for injection containing 0.9% (9 mg/mL) of benzyl alcohol added as a bacteriostatic preservative.
  • It is supplied in a multiple-dose container from which repeated withdrawals may be made to dilute or dissolve drugs for injection.
  • The pH is 5.7 (4.5 to 7.0).
  • The semi-rigid vial is fabricated from a specially formulated polyolefin. It is a copolymer of ethylene and propylene.
Sterile Water for Inhalation : for inhalation solutions
  • Water for injection that is sterilized and contains no antimicrobial agents, except when used in devices in which it is liable to contamination over a period of time (e.g., humidifiers), or other added substances.
  • It is for inhalation therapy only, not for parenteral administration.
Sterile Water for Irrigation :
  • Sterile Water for Irrigation  is a sterile, distilled, nonpyrogenic water for injection intended only for sterile irrigation, washing, rinsing and dilution purposes. pH 5.5 (5.0 to 7.0).
  • Sterile Water for Irrigation contains no bacteriostat, antimicrobial agent or added buffer and is intended for use only as a single-dose or short procedure irrigation. When smaller volumes are required the unused portion should be discarded.
  • Sterile Water for Irrigation, USP may be classified as a sterile irrigant, wash, rinse, diluent and pharmaceutical vehicle.
Sterile Water for Injection : Packaged and rendered sterile used for reconstitution of dry powder injections.
  • Sterile Water for Injection  is a clear, colorless, odorless liquid.
  • It is sterile, hypotonic, nonpyrogenic, and contains no bacteriostatic or antimicrobial agents.
  • Sterile Water for Injection USP is a diluent or solvent suitable for intravascular injection after first having been made approximately isotonic by the addition of suitable solute.
  • pH: 5.5 (5.0–7.0)
  • The EXCEL Container is Latex-free; PVC-free; and DEHP-free.
Sterile Purified Water
  • Sterile Purified Water is Purified Water sterilized and suitably packaged.It contains no antimicrobial agent.
  • Do not use Sterile Purified Water in preparations intended for parenteral administration.For such purposes use Water for Injection,Bacteriostatic Water for Injection,or Sterile Water for Injection.