Water Pharmaceuticals

Water for Pharmaceuticals
Leonid Shnayder
Aker Kvaerner Pharmaceuticals, Bridgewater, New Jersey, U.S.A.

INTRODUCTION Water is one of the key utilities in most pharmaceutical facilities. It is used as a solvent, product ingredient, cleaning agent, and for many other applications. Some of those applications require water of higher purity than typically found in municipal water supplies.Therefore companies install private water purification systems that become a critical part of their utility infrastructure. Why does the potable water from municipal supply require further treatment for pharmaceutical manufacturing? To understand this, let us look into the two main water sources for municipal plants: groundwater aquifers (well water) and surface supplies (rivers and lakes). Asrainwater falls onto the Earth’s surface, it picks up and dissolves atmospherical gases (oxygen and carbon dioxide), industrial emissions such as nitric and sulfuric oxides, as well as bacteria and dust particles. As is passes through the ground into the aquifers, the water is filtered and becomes quite clean, free of most particles and organic contaminants. However, it now dissolves minerals contained inthe limestone and other geological materials. That adds calcium, magnesium, sodium, iron, chlorides, sulfates, and other ions to the ground water. The surface waters found in the lakes and rivers collect organic materials and particles from vegetation and ground runoff. Municipal water plants provide limited treatment, mostly intended to make the water safe to drink. A lot of contaminants, suchas salts, dissolved gases, and organic materials contained in natural sources, remain in the municipal water supply. In addition, chlorine or other disinfectants are often added as part of the treatment process to control microbial contamination. For many critical applications required in pharmaceutical plants, such water quality is not sufficient, and further treatment is necessary.

steamsystem). On the other hand, water used as an ingredient for an injectable drug has to meet much more stringent quality requirements. The US Pharmacopeia (USP) contains specifications for several grades of water used in the preparation of medicinal products. The two grades most often used in the pharmaceutical plants are USP Purified Water and Water For Injection (WFI). As the name implies, WFI is usedfor the preparation of injectable drugs, whereas USP Purified Water can be used in the manufacturing of tablets, capsules, creams, lotions, etc. These types of water are called ‘‘compendial’’ because their quality is specified in an official nationally recognized standard such as USP. In addition, many companies use various noncompendial water systems designed for specific needs. While designingthe facility, it is important to decide on the proper grades of water to use in various applications. Compendial waters are typically very expensive, not only because of required treatment steps, but also because of extensive validation and testing requirements. Therefore it is prudent to limit their use to processes where such water becomes an ingredient of the pharmaceutical product, is in directcontact with such product, or is used for the final rinse of critical process equipment. For most other applications, various noncompendial grades of water (potable, softened, deionized, etc.) can be successfully used without any regulatory conflicts. It is not uncommon to install a water system that produces water that could easily meet the USP specification yet is not designated as USP PurifiedWater to avoid unnecessary expenses for regulatory compliance. The current edition of USP[1] establishes the following requirements for USP Purified Water:
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GRADES OF WATER USED IN THE PHARMACEUTICAL FACILITIES The water purity required varies widely with the application. For example, water used to feed the boilers producing plant steam only needs to be softened (to avoid scale...