The ancillary action is when the main mode of action is due to the device and a medicine is incorporated within a medical device with a supporting function. Medicinal product is any substance or combination of substances intended to treat or prevent disease in human beings. Any substance or combination of substances that may be administered to humans for the purpose of making a therapeutic diagnosis or restoring, correcting or modifying physiological functions in humans shall be treated as a medicinal product. The action of the medicinal substance must be ancillary to the principal action of the device, not based on it.
In addition, the intention of the manufacturer regarding the effect of the substance on the device or organism is not relevant for deciding whether the substance will be considered a medicinal product, as intentionality is not mentioned in the MDR legislation in question. Therefore, the manufacturer's intentions regarding the effect of a substance on an article or organism are irrelevant in deciding whether a substance will be considered a medicinal product. What matters is the actual mode of action of the substance on the body, based on general scientific knowledge. If it is the mode of action through a pharmacological or immunological or metabolic pathway, the substance will be considered a medicinal product.
The action of substances ancillary to the action of a device is to be understood as occurring in or on the human body or its components (e.g. blood, organs, in vivo or ex vivo, gametes, wound exudate) and assisting the device in achieving its specific medical use. We can only speak of the ancillary action of a medicinal substance in a medical device if the removal of the medicinal substance from the device does not alter the essential intended action and use of the medical device. If a device devoid of a medicinal substance will not have the same indication, use, action, it cannot be said to be ancillary to the medicinal substance, but the main action. Consequently, the product will not meet the definition of a medical device, but the definition of a medicinal product (drug).