Liquid assets

Trials and validation for pharmaceuticals may take years and revalidation as a result of changes made to your process are expensive; the most cost-effective way to produce pharmaceuticals is to develop an understanding of the critical phases involved and get the equipment specification right from the outset, explains Mark Bosley, business support divisional manager at Purite.

Many pharmaceutical companies start out by manufacturing from a modest base, often working from a small business unit and then scaling-up their operations as demand grows or new product lines are taken on. This is also true for established manufacturers that are developing new products, as they will start from a low base, using small-scale laboratory testing before bringing new pharmaceuticals to market. From a ‘benchtop’ or laboratory operation, a successful pharmaceuticals enterprise can soon migrate to a pre-production pilot plant and then ultimately on to high volume production.

From the perspective of water purification, moving from low volume laboratory trials through to batch or full production should not be a complex process. The key consideration is that the inherent nature of the product being manufactured remains unchanged as does the quality of purified water required to produce it.  

The first step would be to commission the drafting up of a document typically referred to as a (URS) or User Requirements Specification. The (URS) typically scopes out and defines the requirements of the water purification system. It should be detailed enough to provide sufficient information to allow any water purification system provider to propose a working solution to meet the requirements necessary to provide purified water at the specified quality, quantity, consistently; day in, day out.

The first stage of the water audit would typically involve the taking of representative samples of your incoming feedwater supply for detailed mineral and microbiological analysis. This information may already be available from your local authority or water supplier if you are using a mains supply but should nonetheless be checked; if a surface water or borehole source is being used then a detailed analysis of water characteristics is crucial. An evaluation of the pre-treatment system can be made and a specification be drawn up. If water conditions are variable, then the design of raw water treatment systems and the provision of pre-treatment will need to be suitable for worst case conditions.  

The next stage would be to evaluate the necessary size of the water purification units.  Calculating the maximum demand and also establishing the volume needed on a regular basis will ensure that any immediate and forthcoming needs are catered for and prevent any unnecessary expense further down the line that may be incurred by altering the design and necessitating revalidation.

The method by which pure water is drawn into the process must also be considered. For example, if supplies are required at different locations a centralised system feeding a ring-main may be more appropriate, offering an unobtrusive and space-saving option that can deliver high volumes and high quality. Providing the right capacity can also mean that storage has to be part of the solution. 

Depending on the application, higher volume production operations essentially use scaled up versions of the smaller water purification systems, perhaps supplemented by systems such as: sand and multi-media filters, for eliminating particulates; activated carbon adsorption systems for the removal of organic contaminants and chlorine compounds that can affect colour, taste and odour; cartridge filtration, for pre-treatment; and reverse osmosis for the removal of ionic contaminants.  In addition, ion exchange technology is often used to soften and deionise water, with UV irradiation and membrane filtration commonly being added to maintain microbiological integrity.  Reverse osmosis (RO) is one of the most commonly used technologies and incorporates specialised semi-permeable membranes through which pressurised feed water is passed to remove inorganic ions and dissolved organic contaminants. 

Once the water side of the audit has been completed consideration should be made as to the operation and functionality of the intended equipment. Within the (URS) document a section relating to ‘System Definition’ may include for example, details as to the preferred functionality and operating regime. Once you have considered all of these areas you will then be in a much stronger and clearer position to create a small final ‘model’ of what will be the larger system. 

To assist you in all these considerations, select a suitable water purification provider with a proven track record; the best supplier is unlikely to be the one with the cheapest unit price for the system but one you feel you can work with and which can provide ongoing expertise and support.