Pharmaceutical Water Analysis

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Pharmaceutical Water Analysis

Water is one of the major commodities used by the pharmaceutical

industry. It may be present as an excipient, or used for reconstitution of products, during production of the finished product or as a cleaning agent for rinsing vessels, equipment, etc.Different grades of water quality are required depending on the different pharmaceutical uses. Several are described in the European and US monographs such as Water for Injections, Purified Water and Highly Purified Water. They are generally produced by continuous processes and used in products and manufacturing processes soon after generation and well before the definitive test results are available.Water systems are particularly susceptible to the evolution of tenacious biofilms of microorganisms, especially if they work under ambient conditions. Once installed, biofilms continuously release microorganisms into the water leading to a risk of out-of-specification test results. Failure to meet a compendial specification would then require an extensive product impact investigation, substantial remedial actions within the water system that may include a complete shutdown and a pass/fail decision on all product lots between the previous sampling's acceptable test result and a subsequent sampling's acceptable test result. Therefore, control of the quality of water, in particular, the microbiological quality, is a major concern for the pharmaceutical industry.The objective of a water system microbiological monitoring program is to provide sufficient information to control and assess the microbiological quality of the water produced. The method used for microbial monitoring should be capable of isolating the number and type of organisms that have been deemed significant relative to in-process system control and product impact for each individual system. As process control indicators, alert and action levels are designed to allow remedial action to occur that will prevent the water system from deviating completely out of control and producing water unfit for its intended use. Alert and action levels should be derived from an evaluation of historic monitoring data called a trend analysis. The method used for pharmaceutical water analysis and the testing conditions are designed to avoid extrinsic contamination. The size of the sample is to be chosen in relation to the expected result and at least 200 mL for water for injection and highly purified water. If the colony counts are low to undetectable using the indicated minimum sample volume, it is generally recognized that a larger sample volume should be tested in order to gain better assurance that the resulting colony count is more statistically representative. The membrane filtration method is therefore the worldwide standard for pharmaceutical water testing.