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surface but most were visible only under microscopic examination. Slight streaking appeared on the surface of the automatically de-inked aspirin coating in some places (Figure 2b). In the manual de-inking process, some color- ing was removed from the aspirin tablets. Inspection by light microscopy of a cross-section of a control aspirin tablet revealed two distinct coating layers, with the outer layer containing the color (image not shown). Although not visually observed, it is possible that some of this color layer was also removed in the automatic de-inking process, causing the striations. The tablet and capsule surfaces were also examined using electron microscopy. Ink spots were not seen on either the Advil (not shown) or aspirin tablets after de- inking by either method (Figure 4), although this may be due to the electron microscope's smaller field of view. The surface of the de-inked aspirin tablet appeared rough compared to that of the control, irrespective of the de-inking method used, as seen in Figure 4. This, too, might be re lated to partial removal of the outer color layer. Inter estingly, cracks were noted in the coat- ing of the manually de-inked aspirin tablet (Figure 4d). Scanning electron micrographs of the diphenhydramine capsule showed ink spots on the surfaces subjected to automated de-inking but not on the manually de-inked capsule (Figure 5). 10 October 2014 Tablets & Capsules Figure 2 Light microscope images of enteric-coated aspirin tablets a. Control (unaltered) b. After automated de-inking b. After manual de-inking Figure 3 Light microscope images of diphenhydramine capsules a. Control (unaltered) b. After automated de-inking b. After manual de-inking Figure 1 Light microscope images of Advil tablets a. Control (unaltered) b. After automated de-inking b. After manual de-inking