Hi Heba
The difference between the distilled water (DW) and water for injection (WFI) is mainly based on their physical, chemical and microbiological properties.
A typical distilled water system consists of various stages, each one is designed for further purification of water. The first step is known
as "pretreatment" and the aim of is to modify the supplied water quality until it is suitable for final treatment. The next step is known as “final treatment” and
mostly consists of passing the pretreated water through the reverse osmosis modules. Before its storage, the treated water is passed through a UV lamp to
reduce the microbial load.
WFI has the highest purity possible and it is sterile. It is mainly used as a medium in the preparation of injection solutions
and must therefore. have the highest level of chemical purity and must be completely sterile.
For some applications, sterilising filtration is acceptable (microfiltration through 0.22 μm filters) as a way of obtaining sterile solutions,in the case of WFI, distillation is the only accepted method. Industrially, WFI is obtained by means of condensing clean steam coming from a generator supplied with distilled water (DW). WFI is condensed and is generally kept at 80 - 90 ºC to maintain its properties.
Dear Heba,
Bacteriostatic Water for Injection, USP 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).
Water for Injection, USP is chemically designated H2O.
Store both products at 20 to 25°C (68 to 77°F)
They can both be used for Intramuscular injection, Intravenous injection and subcutaneous injection. I hope this helps. Here is a website which will give you more information. I hope this helps once again!
http://www.drugs.com/pro/bacteriostatic-water-for-injection.html
Regards,
Abhishek
Water for injection is basically sterile, nonpyrgenic and with absence of particles. Sterile distilled water may contain pyrogens and other nonviable particles that may be harmful while administration i.v.
Mr Abhishek has quite clearly defined the differences. The basic purpose in industrial development process is regarding development in line with cost of raw material, such as here Water. A non-pyrogenic injectable would require especial care as also Mr David Bautista reflected. Thus injectable differ as LPN (long term / infusions) and SPN (active admin); nature of water selection is thus critical with respect to the exposure time of such pyrogens clinically.
Thus based on your formulation, requirements of particular water complying with monograph must be considered.
best regards
I guess you can look US Pharmacopoeia or European Pharmacopoeia to understand the limits of the specifications regarding to the different type of waters because like 10 different types of water exist.
Hello Everyone,
It is a simple knowledge-based question. Please do not confuse yourselves. The correct answer:
Sterile water for Injection is Sterilized Pyrogens free water commonly used in Compounding of Parenteral products or small Lab. batches where no terminal sterilization is required.
Water for Injection, USP; on the other hand is Pyrogens free water for use in large scale manufacturing, where the final product is terminal sterilized accordingly.
from USP Water for Pharmaceutical Purposes:
Distilled water = Water For Injection
Sterile Distilled water = Sterile WFI.
“Sterile Water for Injection (see the USP monograph) is Water for Injection packaged and rendered sterile. It is used for extemporaneous prescription compounding and as a sterile diluent for parenteral products. It may also be used for other applications where bulk Water for Injection or Purified Water is indicated but access to a validated water system is not practical, or where only a relatively small quantity is needed. Sterile Water for Injection is packaged in single-dose containers not larger than 1 L.”
So the way I see it, the difference between those two is that:
1/ Sterile WFI (or Distilled water) is packed in containers and used for dissolving or diluting substances or preparations for parenteral administration before use.
It has extra tests to comply with (pH 5.0 to 7.0 Chloride (mg/l) 0.5 Sulfate (mg/l) 1.0 Ammonia (mg/l) 0.03 Calcium (mg/l) 1.0 Carbon Dioxide (mg/l) 5.0 Oxidizable Substances Pass the USP Permanganate test Bacteria Purified Water (CFU/ml) 100 WFI (CFU/100ml) 10 Sterile PW — Pass the USP Sterility test Endotoxin WFI (EU/ml) 0.25)
2/ WFI (in Bulk I assume) is the Water for the preparation of medicines for parenteral administration when water is used as a vehicle. It contains no added substances
sterile water for injection is sterile water to make a solution for injectable preparations.
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