1. The EU MDR defines 'body orifice' to mean any natural opening in the body, as well as the external surface of the eyeball, or any permanent artificial opening, such as a stoma.
2. In the context of medical devices, the Commission has traditionally interpreted wholly or mainly "absorbed" to mean the degradation of a material within the body and the metabolic elimination of the resulting degradation products from the body. The MDCG (see MDCG 2021-24) has maintained this definition, except that they added "in the context of implantable devices". Indeed, this definition of "absorbed" wasn't specifically intended for use in association with Rule 21, and I know of no further definition for that specific context. However, the MDCG has stated for Rule 21 that manufacturers of substance-based devices should provide clear information supporting the mode of action through which the substance achieves the intended specific medical purpose as a basis for the application of this rule, including the site of application as and the site where the action is achieved in or on the body. So you would need to see if the aforesaid definition for 'wholly or mainly absorbed', possibly with adaptations, would fit and could be leveraged for your device's mode of action.
Regarding whether absorption of water would trigger, for example, the class III provisions of Rule 21, my personal opinion is that the presence of the device's
other substances would essentially render the presence and absorption of the water a moot point. The MDCG has said that this rule is for "exclusively substance-based" devices, and that 'substance' in this context means any "matter" that is part of the medical device. From my degrees in chemistry and biology, water is a form of matter, and thus would, technically speaking, be included in the scope of this Rule. But again, to me, that seems to be a moot point, as the device's
other constituent substances are the primary concern for such a device.
3. The MDCG has defined 'l
ocal dispersion' to mean the condition by which substances remain in a specific site without being distributed into the body via the blood and/or lymphatic system.
Hope this helps.------------------------------
Kevin Randall, ASQ CQA, RAC (Europe, U.S., Canada)
Principal Consultant
Ridgway, CO
United States
© Copyright 2022 by ComplianceAcuity, Inc. All rights reserved.
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Original Message:
Sent: 09-Nov-2022 09:44
From: Anonymous Member
Subject: EU MDR classification rule 21
This message was posted by a user wishing to remain anonymous
Hello RAPS community,
Devices that are composed of substances or of combinations of substances that are intended to be introduced into the human body via a body orifice or applied to the skin and that are absorbed by or locally dispersed in the human body are classified as:
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class III if they, or their products of metabolism, are systemically absorbed by the human body in order to achieve the intended purpose;
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class III if they achieve their intended purpose in the stomach or lower gastrointestinal tract and they, or their products of metabolism, are systemically absorbed by the human body;
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class IIa if they are applied to the skin or if they are applied in the nasal or oral cavity as far as the pharynx, and achieve their intended purpose on those cavities; and
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class IIb in all other cases.
Can you please help understand the above classification rule 21 from EU MDR?
1. Isn't body orifice part of skin? What's the difference here in mode/point of application?
2. Absorbed: does this apply to ANY kind of component? For ex, if a medical device is in form of a formulation that is composed majority of water, is water considered to be absorbed, and hence, the device in-turn is "absorbed"?
3. Locally dispersed: Does this mean that the product is spilled around the surface of application, or it only means dispersed in terms of blood flow or via lymphatic system in the body?
I appreciate your insight on the topic.
Thank you,
Another RAPS fellow