Multicomponent Chemical Imaging of Pharmaceutical Solid Dosage Forms with Broadband CARS Microscopy
Christopher M. Hartshorn, Marcus T. Cicerone, Young J. Lee, Charles H. Camp, John M. Heddleston, Patrick Marsac, Tim Rhodes, Zhen Liu, Nicole Canfield
We compare broadband coherent anti-Stokes Raman scattering (BCARS) microscopy with spontaneous Raman microscopy for quantitative and qualitative assessment of multicomponent pharmaceuticals. Indomethacin was used as a model active pharmaceutical ingredient (API) and was analyzed in a tabulated dosage form, embedded within commonly used excipients. In comparison with wide-field spontaneous Raman imaging, BCARS acquired images 10X faster, at higher spatial resolution and with spectra of much higher quality, eliminating the need for multivariate methods to identify chemical components. BCARS was 100X faster than confocal spontaneous Raman but provided similar spatial resolution and spectral quality. The significant increase in imaging speed and spectral quality allowed identification of an unanticipated API phase that was missed by the spontaneous wide-field method.