This article discusses two types of Pharma water system and how they work to produce water for various pharma processes
Water is the basic raw material in the pharmaceutical industry and is used in almost every pharma operation. If the water is contaminated, it will contaminate every product and equipment in which it is being used. So to avoid contamination through water, it is treated in specially designed equipment called pharma water system.
Water Treatment is an integral part of the pharmaceutical operation, to treat raw water according to the pharma requirements. It employs various techniques to remove water contaminants, microorganisms, and impurities to make it safe for various pharmaceutical processes and functions.
The incoming water passes through various stages in a treatment plant, where different processes occur. The combined effect of all stages results in output water having all the required properties that can classify as treated water. The water coming from the final stages can be used in different pharmaceutical processes such as manufacturing and washing.
Capacity of pharma water system
The capacity of water systems is described in Liter per hour – LPH. It means the amount of water in liters that a water treatment plant can generate in one hour.
For example, a water system of 10,000 lph means it can produce 10,000 liters of treated water in one hour.
General requirement for Pharma Water System.
Pharmaceutical Water System is highly critical and requires special care and consideration during its production. The required properties of water can only be achieved if strict control in terms of standardization and contamination is put in place during the entire production process.
Some general requirements for pharmaceutical water systems are mentioned below.
- The product water contact parts must be SS316L, with suitable polishing.
- All the metallic surfaces must be free from dead points
- The outer frame and the components that do not come in contact with product water must be made up of SS304.
- All piping and tubing must be according to ASME BPE standards.
- Surface roughness must be less than 0.8Ra.
- All piping and tubing must be orbitally welded with sanitary fittings
- Heated parts must be protected by insulation or by deploying a double sheet.
Types of pharma water system
The pharmaceutical industry utilizes a different processes for its various production activities. Each process requires different input methods and materials with the required properties and qualities. Similarly, water is also a critical ingredient for different processes.
In the pharmaceutical industry, there are mainly two types of water used for processes: Purified Water and Water for Injection. Each type is produced in different water plants known as Purified and Distilled water plants.
Let’s look briefly at both types.
Purified Water Plant
A purified water plant produces water for non-parenteral products, general processes such as Cleaning, and tests where indicated. The purified water must meet the specifications set by USP in terms of microbial and organic contamination.
A purified water plant consists of a series of operations or stages through which water passes. When water comes out of the final stage, it contains the required properties as stated in the USP. Typically, purified water consists of the following stages.
- UV Light
Pre-filtration is the first step in water treatment, which prepares the incoming water for further stages. Because water conditions vary from time to time, pre-filtration is applied before further processing to provide water within limits. Otherwise, it will shorten the life and decrease the efficiency of later stages.
It removes chemical, physical and organic contaminants so that the preceding stages can easily perform the treatment process. Additionally, softening also occurs in the pre-filtration stage.
The softening section includes an exchange resin bed, which removes hard material such as Ca++ ad Mg++ by exchanging from water. Other properties, such as conductivity and salt contents, remain the same and are not changed.
Water remains in constant flow in the pre-filtration section, which helps in preventing contamination and microbial growth.
The softener section must be sanitized to prevent microbial growth. Hydrogen peroxide (H2O2) or Sodium hypochlorite (NaOCl) is used as a sanitizing agent at a high temperature of around 80°C.
In addition to the softener, prefiltration can also consist of a sand bed, chlorinator, anthracite filter, activated charcoal filter, degasifier and microfilter. The selection of pre-filter components mainly depends upon the feed water quality and the product water requirements.
The filtration section is the second stage, where the processed water is passed through a Reverse Osmosis (RO) Membrane. RO membrane is a popular method used in treating water for different industries because it is energy efficient and does not require high temperatures to operate.
In the RO section, the membrane separates pure water from raw water under osmotic pressure. Most organic components with a molecular weight greater than 100 are separated.
During filtration, water is pumped through a membrane with pressure. Pure water comes from the RO filter and is stored for further use. The impurities are blocked by a membrane that remains in them and is drained.
It consists of ion exchange materials. and is sued after RO membrane. In this stage, dissolved salt or mineral ions not captured by RO are removed.
In today’s water treatment plants, ion exchange is executed electronically, without chemicals, called Electro deionization – EDI. In this process, ion exchange resin is placed between the cationic and anionic membranes. DC is used to generate a strong electric field. Charged ions are pulled off the resin towards opposite electrodes. This process occurs continuously during constant water flow through the EDI unit.
In ultrafiltration, water is passed through a semipermeable membrane and is used to filter out substances with high molecular weight and suspended solids.
UF can also remove most organic viruses and almost 90% of pathogens. Additionally, it does not requires any chemicals for the filtration process.
UV light is the last stage in a purified water system. The wavelength of UV light is 254 nanometers (nm), which is enough for achieving microbial reduction. UV light also breakdowns ozone or hydrogen peroxide, which have been previously added as a sanitizing agent.
UV light is fitted in a column in which the water is made to flow. When water flows through it, water is subjected to UV light and performs the corresponding action.
The efficiency of UV light depends upon many factors, including UV lamp, path and speed of water flow. If the strength of the UV lamp is weak, it will affect the filtration process.
Distilled Water Plant
The distilled water plant is used to produce the special grade of pharma water called Water for Injection – WFI. It is used in manufacturing parenteral and where strict control of endotoxin is necessary.
Many methods are acceptable for WFI production, such as Distillation and Membrane-based systems, but distillation is considered safe and more reliable than any other method.
Let’s briefly discuss the distillation water plant.
Unlike purified water plants, where the feed water can be of raw quantity, distilled water requires high quality feed water. For this purpose, water from the purified water plant becomes the input of distilled water plant.
In distilled water plant, water is heated to convert into steam. The steam is then cooled down for condensation to occur, which converts the steam into the water of the desired purity.
Distilled water plant consists of columns where heating and cooling take place.
Before the heating chamber, there is a pre-heating chamber that initially increases the temperature. Its main purpose is to uniformly heat the entire water quantity for uniform heat transfer.
In the heating chamber, the temperature is high enough to convert water into steam. When the purified water is converted into steam, it leaves behind all the contaminants and Pyrogens.
In the next column, the steam is cooled down to convert into water. Since all impurities have been left behind, the converted water is free from these impurities and meets the standards of Water for Injection. From the discharge port, all impurities leave the distillation plant.
To prevent impurities generation in WFI, the water must remain in circulation at high temperatures, typically 80⁰C. It becomes difficult for microbial to grow and contaminate water at this temperature.