Medicinal products and medical devices alike can be used to diagnose, prevent, treat, and alleviate diseases, or to correct, restore or modify physiological processes. The essential difference between medicinal products and medical devices is that the mode of action of medicinal products is either pharmacological, immunological, or metabolic. For medical devices, the intended effect is principally based on e.g., a chemical or physical mechanism.
For most medicinal products, the mode of action is pharmacological. The drug molecule binds to its target receptor, which in turn is either activated or blocked. Vaccines and allergen preparations used for desensitization are good examples of medicinal products with an immunological mode of action. Metabolic action refers to modification of the body’s natural chemical processes, e.g., when statins are used to reduce cholesterol synthesis.
The chemical and physical modes of action of medical devices can resemble those of medicinal products. However, the active ingredients present in medical devices do not bind to receptors or enzymes and they do not affect the immune system. For example, eye drops can be used to restore diminished volume of tear fluid or improve the quality of tear fluid so that evaporation of water from the ocular surface is reduced. Medicinal devices can also be taken orally, e.g., to soften stools by increasing the amount of water in the intestinal lumen or to neutralize gastric acid.
The principal mode of action of medical devices can be assisted by means that are characteristic to medicinal products. An example of this are device-drug combination products such as drug eluting stents implanted in coronary arteries. The principal mode of action is based on the mechanical effect of the stent, keeping the blood-flow path open. The drug that is released from the polymer coating of the stent assists this effect by preventing overgrowth of the vascular tissue that would result in restenosis.
To secure a smooth path to the European market, the mode of action and, consequently, the status as a medicinal product or a medical device must be defined already during the product development. If your company needs assistance in the interpretation of legislation applied to different types or products, or in defining the mode of action, the experts at DRA will be happy to help you!