Water is widely used in pharmaceuticals for Batch manufacturing, active pharmaceutical ingredients, and analytical reagents. So, according to pharmacopeia, different types of water are recommended, but as per the official book and pharmacopeia (IP, BP, USP, NF, EP), highly purified Water is recommended.
The different types of water grades and their use in the manufacturing process are described in this article.
Uses benefit of Water in Pharmaceuticals
Water may present as an excipient, or it may be used to reconstitute products during synthesis, during the production of the finished product, as a clinic agent for rinsing equipment, primary packing materials, and vessels.
There are several types of Water is used in pharmaceuticals but depending upon their quality and purpose of using different types of Water defined here for understanding the terminology.
9 Types of Water in pharmaceutical according to USP
- Drinking or Potable water:
- Purified Water:
- Water for injection (WFI)
- Sterile Water for injection(SWFI):
- Bacteriostatic Water for injection:
- Water for hemodialysis:
- Sterile Water for irrigation:
- Sterile Water for inhalation:
- Water for analytical purposes:
1. Drinking or Potable water
Drinking water in pharmaceuticals shall comply with the standard specified by the Bureau of the Indian standard of WHO, Drinking water standard, and US potable water standard 40 CFR 141. Indian pharmacopeia has given a 500 CFU/ml limit for the total aerobic microbial count for drinking potable Water.
Purposes of Drinking water:
- For use as a drinking water
- Preparation of external use products
- Washing and extraction of crude drugs
- Purified Water:
Purified Water Means Water intended for human consumption and maybe sealed in bottles and other containers with no added ingredients.
P. water is prepared by distillation, ion exchange, or any other appropriate means from suitable potable Water.
The purification process shall comply with standards given in monographs of official books and pharmacopeia. The limit for the microbial population for purified Water is 100 CFU\ml. Pathogen shall be absent in purified Water.
Difference between purified Water and potable Water
Pure Water: Pure Water contains no minerals or side chemicals. It is pure H₂O and only contains Hydrogen and Oxygen. Pure Water has been mechanically filtered to remove all impurities and make it suitable for use. Distilled Water is the commonest type of pure water.
Pure Water is often employed in preparation, drinking, scientific studies, and laboratories. Nowadays, Water is frequently purified by processes like capacitive deionization, carbon filtering, reverse osmosis, micro-filtration, ultra-filtration, and ultraviolet oxidation.
Potable Water: Potable Water is Water that is fit for consumption by human beings and other animals. It is also called drinking water. It is safe for drinking and food preparation, without the risks of health problems. Water that is contaminated is often treated to show it into potable water.
One of the easiest ways to treat water is heating to boil. Boiling the Water might not remove heavy contaminants, but it can neutralize most bacteria and viruses which can be present. Water may be treated chemically like bleach.
2. Water for injection (WFI)
Water for injection (WFI) is also part of the purified water system in pharmaceuticals as an excipient in the production of parenteral and other preparation. Using WFI Product endotoxin content must be controlled and other purposes such as cling of context part of the equipment when Water is used as a vehicle(Water for injection in bulk). It is also used for dissolving or diluting substances and in preparation for injections.
The pH of Water for injection is 5.0. It may range from 5.0 to 7.0.
Use of Water for injection
- For the production of parenteral products to protect from microbial growth or contamination.
- For cleaning purposes of contact part components in parenteral products.
Preparation Technique of Water for injection
Water for injection is prepared by Distillation of potable Water or Purified Water, Reverse osmosis, and Membrane process.
Storage of Water of injection (WFI)
The first portion of the distillate is discarded, and the remaining is collected and stored in a special tank containing ultraviolet lamps or in a sealed container. It can be stored for a period of up to a month.
Difference between purified Water and WFI
Water for injection is highly purified as it is condensed and kept at 80-90 degrees Celcius to maintain its properties. It is stored in a single dose for Iv administration purposes after adding the required amount of solute. In contrast, purified Water is kept at room temperature.
4. Sterile water for injection(SWFI)
Sterile Water for injection is sterilized within 12 hours of collection and distributed in sterile.
It should be packed only in a single dose container, not larger than a 1-liter size. It should comply with the standards given in the monograph of official books or pharmacopeias.
The recommended microbial limit is not more than 10 CFU per 100 ml, and the pathogen should be absent.
For both WFI and SWFI, the total organic carbon (TOC) as per IP is not more than 0.5 mg/ liter. In contrast, the same limit of TOC for Water (500 PPB) in USP and BP.
Preparation technique for SWFI
Sterile Water for injection is prepared By distillation of Water.
Use of sterile Water for injection
It is intended mainly for use as a solvent for parenteral preparation, such as powder for injection. It is distributed as dry because of the limited solubility of its solution.
5. Bacteriostatic Water for injection
Its suitable microbial preservatives are added into sterile Water for injection.
It is used in parenteral products as a diluent, mainly for multi-dosage products requiring continuous contents withdrawal. It should be packed in not larger than 30 ml containers either in a single dosage or multi-dosage.
6. Water for Hemodialysis:
Water for hemodialysis is used as a diluent for hemodialysis concentrate solution. It is produced from EPA (regulatory agency for regulating drinking water to protect public health), purified Water treated to prevent microbiological and chemical attacks.
This Water is not intended for injection. It shall be store in an unreactive container and also avoided microbial attack.
7. Sterile water for irrigation
Sterile Water for irrigation is Water for injection that is packaged and sterilized in single-dose containers. Store in Container sizes larger than 1 liter. It allows quick delivery of contents not mandatory to meet the requirements for small-volume injections.
It is used for applications that don’t have particulate specifications or wherever pure Water or Water for injection is indicated. However, access to a good water system is absent or larger quantities of Sterile Water for injection are required.
8. Sterile Water for inhalation
Sterile Water for inhalation is Water for injection, which is packaged and sterilized. It is employed in inhalators and the preparation of inhalation solutions.
It is not suitable for parenteral applications because it carries less stringent specifications for bacterial endotoxins than Sterile Water for injection.
9. Water for analytical purposes:
Distilled Water, freshly distilled Water, Deionized Water, high purity water, and Carbon dioxide-free water are incorporated for Analytical purposes.
Types of Water in pharmaceutical topics concluded that Water for pharmaceutical management is a critical part for a pharmaceutical manufacturer throughout the process for the operation.
With unique design and proven technique, the innovative operation can provide a better solution. Results on the low cost, minimum regulatory compliance, and a low risk to a business.
The proposed design is easy, economical to maintain, and ecological because it has no high-efficiency filters, eliminating the constant regeneration of the ionic exchange resins.
It should also be pointed out that stainless steel tanks for decalcified and purified Water can be sterilized regularly through clean steam.
Therefore, validation of the system will ensure the production of Water will be dependable and within the specified limits. In this case, it will be easy t0 prove that the price of the purified Water will be competitive and, in practice, less expensive than another water-producing system.