Until the early 1990s, HPLC was used almost exclusively for cleaning validation purposes. However, in the mid 1990s, the USP approved TOC as the replacement for the Oxidizable Substances Test previously used for Water for Injection (WFI) and Purified Water (PW).

As most pharmaceutical companies currently have a means of analyzing TOC for USP, there is a desire to use TOC measurement for cleaning validation purposes, as well. Because residue limits and historical data will be specific to HPLC measurement, it is desirable to create a correlation when moving from HPLC to TOC measurement for cleaning validation. To accomplish this:
- Perform Cleaning Validation on selected products via HPLC
- Determine TOC for these products at the same time
- Correlate HPLC data to TOC data
- Establish database and Statistical limit for TOC
- Collect TOC residues on other products and show equivalent cleaning

Benefits of TOC analysis for cleaning validation:
- Non-specific measurement for carbon
- Almost all facilities currently have TOC for USP testing
- Ease of use/cost of ownership
- High recovery of samples
- Low LOQ
- Minimal interferences
- Only provides upper limit value

Skytech Systems(I) Pvt. Ltd.
Email: wasank@skytechindia.com