How to develop and validate a total organic carbon method for cleaning applications

Good Manufacturing Practices require that the cleaning of drug manufacturing equipment be validated. Common analytical techniques used in the validation process include HPLC, UV/Vis, and Total Organic Carbon (TOC). HPLC and UV/Vis are classified as specific methods that identify and measure appropriate active substances. TOC is classified as a non-specific method and can detect all carbon-containing compounds, including active substances, excipients, and cleaning agents. The disadvantage of specific methods is that a new procedure must be developed for every active drug substance that is manufactured. This development process can be very time consuming and tedious. In contrast, one TOC method can potentially be used for all products. A TOC method is sensitive to the ppb range and is less time consuming than HPLC or UV/Vis. USP TOC methods are standard for Water for Injection and Purified Water, and simple modifications of these methods can be used for cleaning validation. The purpose of this study is to demonstrate how to develop and validate a TOC method for cleaning applications. Performance parameters evaluated in this study include linearity, MDL, LOQ, accuracy, precision, and swab recovery.