Anticounterfeit protection of pharmaceutical products with spatial mapping of X-ray-detectable barcodes and logos.
Counterfeit pharmaceutical products are a global threat to public health, and they undermine the credibility and the financial success of the producers of genuine products. The escalating circulation of counterfeit drugs demands new anticounterfeit measures that permit rapid screening, are nondestructive, and cannot be circumvented easily. Herein we describe a micro-X-ray diffraction (μ-XRD) protocol for this purpose capable of reading barcodes and logos fabricated on various substrates using soft-lithography stamping of compounds that can be read by X-ray diffraction but are invisible to the naked eye or optical microscopy. This method is demonstrated with barcodes and logos of compounds, approved by the Food and Drug Administration, printed on flat substrates as well as commercial aspirin and ibuprofen tablets. The μ-XRD protocol is nondestructive, automated, and user-friendly and can be used to certify the authenticity of drug tablets by mapping hidden patterns printed under the tablet coating and on packages.