Three Raman maps have been acquired, moving from a large area low resolution whole tablet image, through to a high resolution small area of interest to analyse individual grains/particles in detail.

In the whole tablet map (1), covering a 7 x 18 mm² area, the major constituents of aspirin (red), paracetamol (green) and caffeine (blue) are visible, in addition to the tablet coating (pink).  A higher resolution image (2) highlights a fourth component (cellulose – in yellow) widely spread across the tablet, but present only in small, discrete areas.  The final image (3) was acquired with 2 µm step, and allows the size and shape of individual cellulose grains to be observed.