Affixing UDI on Medical Device Labels

To date, class III, IIa, and IIb medical devices compliant with Regulation (EU) 2017/745 must affix the UDI code on the label. In May 2025, this requirement will also become mandatory for class I medical devices.

On the eve of this deadline (yes, 7 months from now in the medical device world is just a few days), it’s important to ask if everything is ready for affixing the UDI code on labels.

UDI Code Representation

The UDI code, composed of its two parts UDI-DI and UDI-PI, is assigned to the device itself (or its packaging) and to all intended non-logistical packaging levels.

This code is represented in two formats:

• HRI Format – Human Readable Interpretation (Human Readable Interpretation): alphanumeric string including all information required, according to the adopted standard, to indicate the UDI code
• AIDC Format – Automatic Identification and Data Capture (Automatic Identification and Data Capture): graphical representation of the UDI code information that allows automatic reading. Various formats are provided and allowed depending on the chosen issuing agency. The types of formats provided are ID/linear barcode, 2D barcode, and RFID.

Exceptions

Do the same rules apply to all devices? No, that would be too easy.
The regulation, in part C of Annex VI, specifies some cases where exceptions are allowed on how to affix the UDI code.

Single-use Class I and IIa Devices that are Individually Packaged and Labeled

The UDI carrier does not need to appear on the packaging of the individual device but can appear on an outer level of packaging, for example, on a carton containing multiple individually packaged devices. However, when the healthcare facility is not expected to have access to the outer level of device packaging, such as in home healthcare settings, the UDI is placed on the packaging of the individual device.

Devices Intended Exclusively for Retail Point of Sale

The UDI-PIs in AIDC do not need to appear on the point of sale packaging.

Reusable Devices

Must bear the UDI carrier on the device itself, thus through direct marking, unless:

• Any type of direct marking would interfere with the safety or performance of the device;
• The device cannot be directly marked because it is not technologically feasible.

Single-use Disposable Devices Contained in a System or Procedure Kit

Are not required to bear their own UDI carrier if not intended for individual use outside the context of the system or procedure kit and if their uses are generally known to the people for whom they are intended.

Medical Device Software

When the software is provided on a physical medium, such as CD or DVD, each packaging level bears the complete UDI in both HRI and AIDC formats. The UDI applied to the physical medium containing the software and its packaging is identical to the UDI assigned to the system level of the software.
Only the human-readable part of the UDI must appear mandatorily in electronic displays of the software. The UDI in AIDC format is not necessary in electronic displays, such as the device information menu, loading screen, etc.

Where not otherwise Specified

In case of significant constraints limiting the use of both AIDC and HRI formats on the label, only the AIDC format may appear. For devices intended to be used outside healthcare facilities, such as home care devices, the HRI must appear on the label even if this means there is no space for the AIDC.

UDI Code Print Quality

Once the requirements for various devices are clarified, we can focus on the affixing of the UDI code phase, i.e., placing the UDI information on the product and relevant packaging levels.
The MDCG 2021-19 summarizes the steps organizations should follow to best manage the integration of UDI into their processes.
Among others, the need to ensure that the label printing process is verified and validated emerges.

What it Means to Verify the UDI Printing Process

Verifying the label printing process bearing the UDI code means ensuring that the print quality obtained following all the steps necessary to create the label is sufficient.
Sufficient with respect to the issuing agency’s standard which, in turn, refers to the specific ISO standards for the chosen carrier type, typically ISO/IEC 15415 or ISO/IEC 15416.

How to Verify the UDI Printing Process

The output of the printing process, i.e., the label bearing the UDI code, is verified using a dedicated tool called a verifier: an optical reader capable of verifying the degree of correspondence between quality and content of the read code with what is required by the ISO and the specific issuing agency standard mentioned above.

What it Means to Validate the UDI Printing Process

Validating the label printing process bearing the UDI code means implementing a printing process monitoring system such that it can be asserted, with a finite and acceptable level of uncertainty, that all outputs of the printing process (the labels), even if not individually verified, meet the required specifications.

How to Validate the UDI Printing Process

1) As with the validation of any process, the first step is to define the inputs (or variables) of the process that can influence its output (the label).

The main variables in the UDI affixing process are:

• Printing software
• Printing technology and printers
• Printing medium (labels)

Let’s remember that labels made with different methods (e.g., using different printing technologies or printed on different materials or with different colors) constitute different processes, so the following will need to be repeated for each individual process.

2) Once the variables are defined, their control methods are defined, for example:

• An operational instruction explaining how to input data into the label generation software
• A maintenance program for printing equipment
• The technical specifications of the medium on which printing will occur

3) A sample label is created which must be analyzed by a verifier. In case of a negative outcome, start again from point 1 and proceed iteratively to adjust the process until a positive outcome is achieved.

4) Great, the label produced with the process we’ve defined is compliant! As long as the input parameters are not modified and as long as the process is kept monitored, I can consider the process validated and its output repeatable.

Purchasing a Complete and Dedicated System

Validating the printing process for UDI code affixing can require a significant expenditure of resources, both in terms of time and money.
For this reason, in collaboration with specialized partners, we have defined a complete system with everything needed to affix the UDI code on labels with certainty:

• Printer
• Ribbon and labels
• Software for UDI label generation
• UDI label layout

Using the package as proposed ensures a positive outcome in verifier tests (which will still need to be performed) and, if it’s necessary to implement changes dictated by specific needs, it constitutes an excellent starting point for obtaining compliant labels with the least possible number of iterations.