4.1 Medication errors occur when users are confused by the similar size, shape, color, typeface, and layout of labels that are used for a range of a manufacturer's drugs with widely dissimilar actions or potencies. The human visual system uses shape, size, color, and typeface in the initial recognition of a labeled drug. (See 9.1 - 9.3.) The use of this human visual system has been described in 21 CFR 429.12 for the labeling of insulin. Using the similar label design, color, and typeface throughout a product line makes identifying an individual drug more difficult.

4.2 The objective of this practice is to provide guidance for the design of drug labels which will enable users to easily distinguish between drugs of differing action or potency. See Note 1.

Note 1-For specific requirements for these labels and other features of labels for OTC human drugs, see 21 CFR 201.66.