Despite the increased request for robust quality systems, the end product may contain unidentified defects or discoloured regions. The foreign matter has to be monitored, identified and its source defined in order to prevent further contamination. However, the identification task can be complicated, since the origin and nature of foreign matter are various. The aim of this study is to provide an efficient foreign matter identification procedure for various substances possibly originating from pharmaceutical manufacturing environment. The surface or cross-section of the uncoated and coated tablets was analysed by utilization of different analytical techniques, such as light microscopy (LM), scanning electron microscopy in combination with energy dispersive X-ray microanalysis (SEM/EDX), Fourier transform infrared spectroscopy (FT-IR) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results indicate that the combination of different analytical techniques proved to be a powerful approach in foreign matter identification. Light microscopy and SEM generate information on the morphology of foreign matter particles. EDX provides elemental analysis, which most often serves as final confirmation of the identification. However, FT-IR can be used to obtain information on the compounds chemical structure and conformation, and ToF-SIMS provides sensitivity in cases, where the entire solid dosage form is contaminated with foreign matter.
Journal of Pharmaceutical and Biomedical Analysis, 2013, Vol 80, p. 116-125