Abstract: Method for printing on a pharmaceutical tablet by etching a printing plate to form a pattern of etchings therein within an area corresponding to an outline of the tablet, varying the ink-retaining volumes of the etchings in a pre-determined manner and in a direction across the etching pattern from one side to an opposite side, placing ink into the etchings, and transferring ink from the etchings in the etched printing plate onto an outer surface of the tablet. Variations in the ink-retaining volumes of the etchings cause a larger amount of ink to be transferred from etchings having a larger ink-retaining volume than from etchings having a smaller ink-retaining volume during the ink transfer stage. This causes different changes in the color of the outer surface of the tablet dependent on the amount of ink being transferred.

Abstract: Oral solid dosage forms having holographic markings or identification marks such as a watermark thereon and methods of preparing the same are disclosed. One preferred method of applying an identification mark on a pharmaceutical dosage form described herein includes applying a film coating having a first color to an oral solid dosage form such as a tabet and thereafter applying an identification mark to the film coated oral solid dosage form using an ink which not only contains a pearlescent pigment therein but also has a second color which is substantially similar in color to the first color used for film coating.

Abstract: Oral solid dosage forms such as tablets having overt, printed or etched markings as well as optional covert markings are disclosed. The markings can be rapidly identified to authenticate a dosage form and/or drug contained therein. The inventive dosage forms include a core portion having sufficiently low friability to receive a printed or etched marking on a surface thereof, and a readable or detectable printed or etched marking on the surface of the core which provides information allowing the identification/authentication of the oral dosage form. In preferred aspects of this embodiment, a bar code, more preferably, a 2D data matrix bar code is printed or etched on a debossed region on the surface of the solid dose form. Methods of preparing the marked dosage forms and methods of identifying and/or authenticating solid dosage forms are also disclosed.