Fiber optic noncontact reflectance probe for detection of contamination in pharmaceutical mixing vessels

In pharmaceutical manufacturing, it is critical to determine the cleanliness of the reactor walls prior to the blending/formulation process. A remote non-contact, real- time reflectance probe was developed to monitor these cleaning procedures. It utilizes the principals of IR spectroscopy and it works in the mid-IR region, as the ability to obtain spectral information in the mid-IR region not only enables this probe to monitor processes like reactor cleaning, but also to identify contaminants based on their spectral fingerprints. The spectral data can then be compared against-pre-existing calibrations or spectral libraries to determine surface cleanliness or to identify contaminants. This manuscript will discuss the design principles of the probe and present data obtained in actual tests. The non-contact reflectance probe is certainly not limited to its application for determining the cleanliness of reactor walls. Such a probe would find numerous applications in process monitoring and as a research tool for surface analysis and characterization.