All of these methods are collectively grouped into the category of rapid microbiological methods (RMM). In some compendia, these are also called alternative microbiological methods. The methods range from simple dip-stick-type tests to very complex automated systems that perform a variety of tests using a variety of techniques. The prices for these methods vary greatly, from a few dollars to hundreds of thousands of dollars. Although these methods are called rapid microbiological methods, many have their roots in other sciences, e.g., chemistry, molecular biology, biochemistry, immunology, immunochemistry, molecular electronics, and computer-aided imaging.
Rapid microbiological methods provide significant opportunities for pharmaceutical companies to obtain data that may be significantly better than that obtained via traditional methods, may be more cost effective, may provide marketing advantages, and may allow for coordinated process analytical technologies to be fully integrated within a facility.SLOW TO ADOPT NEW METHODS
In recent years, a variety of documents has been issued or drafted to help the microbiologist select, purchase, implement, and regulate the submission of rapid microbiological methods. We discuss six.
Parenteral Drug Association Technical Report Number 33
The Parenteral Drug Association (PDA) was one of the first organizations to develop guidance for evaluating, implementing, and validating rapid microbiological methods. Guidance information was published as Technical Report 33 (PDA TR No 33).1 This document was developed by a committee of individuals from industry, regulatory agencies, compendial groups, and instrument vendors. This guidance provided definitions, in microbiological terms, for validation criteria similar to the information in United States Pharmacopeia (USP) <1225> for chemistry methods.2
USP Proposed Chapter <1223> on Alternative Microbiological Methods Validation
The USP proposed a draft monograph <1223>, Validation of Alternative Microbiological Methods, which defines various validation criteria that may be used for rapid microbiological methods and defines these criteria in terms of microbiology. Additionally, the proposal identifies how to determine which criteria apply to different technologies, based on the type of testing being performed.3