Total organic carbon method for aspirin cleaning validation

Cleaning validation is the process of assuring that cleaning procedures effectively remove the residue from manufacturing equipment/facilities below a predetermined level. This is necessary to assure the quality of future products using the equipment, to prevent cross-contamination, and as a World Health Organization Good Manufacturing Practices requirement. We have applied the Total Organic Carbon (TOC) analysis method to a number of pharmaceutical products. In this article we discuss the TOC method that we developed for measuring residual aspirin on aluminum, stainless steel, painted carbon steel, and plexiglass. These are all surfaces that are commonly found as part of pharmaceutical production equipment. The method offers low detection capability (parts per million levels) and rapid sample analysis time. The recovery values ranged from 25% for aluminum to about 75% for plexiglass with a precision of 13% or less. The results for the plexiglass tended to vary with the age of the surface making the determination of an accurate recovery value difficult for this type of surface. We found that the TOC method is applicable for determining residual aspirin on pharmaceutical surfaces and will be useful for cleaning validation.