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Purified water is an essential ingredient in the manufacturing, formulation, and processing of pharmaceuticals and APIs.

What is purified water system in Pharma?

Purified water, a pharmaceutical-grade water, is widely used in the preparation sterile and/or apyrogenic medicines. It is typically made on-site from potable waters, which must also meet strict quality standards.

What are the uses of purified water?

Purified water is used in pharmaceuticals for everything from cleaning equipment to being one main component in many products and processes. These include:

• Producing oral and topical medications
• Granulation of capsules and tablets
• As the water for WFI (Water for Injection),
• As the feed water for pharmaceutical-grade clean steam
• Cleaning solutions preparation

How to make purified water in Pharma

Pre-Treatment

This initial stage sees the water pass through multi-media filters to remove suspended matter such as mineral salts. This is called ultrafiltration. Different additives can be added to ultrafiltration to fulfill specific functions.

Some pre-treatment processes are listed below.

Softening

The water becomes hardened by salts of calcium and magnesium. Hydrogen peroxide or sodium hypochlorite can be added to the water at temperatures of 80 degrees Celsius. This turns the hard water into soft. The process of electro-de-ionization is also assisted by softening.

Chlorination

To eliminate viruses and bacteria, water is treated with chlorine.

Post-treatment Stage

After adding different additives to the water and passing it through multi-media filters, the water enters the post treatment stage. Here, other processes are performed to purify the water. This allows the water to be certified as purified according to different regulatory bodies.

Purified water can be made using several methods. The process used to make pharma-grade purified waters varies depending on the plant's capabilities and the end user's application.

Dosing System

Dosing serves three main purposes. Anti-scalent dosing is used to remove silica, sulfurates, and other precipitates from the water. This can lead to fouling of filter membranes. This is done by adding sodium hexametaphosphates. To eliminate carbon dioxide from the water, acid like hydrochloric and acetic acids are next added. This is known as pH correction dosing. To remove chlorine added during chlorination, sodium metabisulfite (SMBS) is added to the water. This can be harmful to RO membranes in the pipes.

Electro-Deionization

Another popular way to get purified water is this method. It is more affordable than other methods, and so is preferred by many.

The de-ionization process is based on electrolysis and ion exchange. Its primary purpose is to remove specific ions from water and replace them by more desirable ions.

Water can have different ions, differently charged molecules or atoms. The ions that have a positive charge are known as 'cations', while ions that have a negative charge are known as 'anions'. The EDI module uses ion exchange resins and is separated by ion exchanging membranes. These are basically high-surface electrodes with both positive and negative charges. The water is de-ionized when an electric current passes through it at the right angles. The positively charged cation moves towards the anode, while the negatively charged aniions move toward cathode.

Effectively, De-ionization removes water-soluble particles, such as minerals and salts.

Reverse Osmosis

It is widely recognized as one of the best ways to purify your water. It is widely used in industries that require water as a raw material or resource.

Osmosis is derived from the Greek word "osmos", which means "push". Reverse osmosis is when the natural osmotic flow in the water is interrupted by semi-permeable membranes that force the water to its diluted side.

Reverse osmosis membranes are made from cellulose acetate. They have very small pores, which allows water to flow while trapping microorganisms. The water is rejected by the membranes if it is subjected to high pressure. You must also ensure that the membranes being used in this process are sanitized according to the specified methods. Microbial contaminants can be eliminated by rinsing the membranes in hot water at 80 degrees Celsius. Citric acid is used to remove inorganic impurities from the water passing through the membranes.

Reverse osmosis is effective in removing salts and sugars as well as bacteria and other particles. It cannot remove dissolved gases from the water like carbon dioxide.

Distillation

Another popular method to make purified water is distillation. Distillation is the use of different vapour pressures (volatility), of water and impurities suspended within the water. The water is then boiled in a multi-column distillation machine. The vapours are condensed to get sterile, purified water.

Water for Injection (WFI) is one of the main uses of purified water from distillation. This is a pharmaceutical water that can be used to deliver medicines or drugs directly into patients' bloodstreams.

UV Disinfection

The UV disinfection process is an inexpensive and simple way to purify water. The water is exposed to ultraviolet rays at specific wavelengths with a UV lamp. This UV lamp can be used to kill pathogens like bacteria, viruses and algae.

Apart from the manufacturing of healthcare products, UV disinfection is used in many other applications. Cleaning in Place (CIP) is a method that is used in the pharmaceutical industry to ensure that vessels, equipment, filters, and paraphernalia can be safely used in different pharma operations.

There are many ways to obtain pharmaceutical-grade purified waters that meet specific requirements. Sanpure has nearly 20 years of experience in providing optimized purified water solutions at a low cost per litre. Our team is available to assist you in every step of the process, from design, installation and validation through after-sales support.