Gum Red-Cote Disclosing Plaque Tablets

Is this kosher? They are used to show if teeth have plaque.
Note that these are meant to be chewed, swished in mouth, and then spit out, but they contain cherry flavor.
medicinal ingredients: D&C Red #28
Non medicinal ingredients: cherry flavoring, dextrose/maltodextrose blend, FD&C Blue #1, magnesium stearate, mannitol powder, sodium saccharin

Its ok