ANSI/AAMI/ISO 10993-15-2000 pdf download.Biological evaluation of medical devices—Part 1 5: Identifcation and quantifcation of degradation products from metals and alloys.
4 Degradation test methods
4.1 General
To identify and quantify degradation products from metals and alloys in medical devices, two procedures are described.
The choice of test procedure shall be justified acording to the function of the medical device.
The first procedure described is a combination of a potentiodynamic test and a potentiostatic test. The second procedure described is an immersion test.
The potentiodynamic test is used to determine the general electrochemical behavior of the material under consideration and to determine certain specific points (Ea and Ep) on the potentil/current density curve.
The potentiostatic test is used to electrochemically degrade the test material at a constant potential above the breakdown potential to generate degradation products to be analyzed.
The immersion test is used to chemically degrade the test material to generate degradation products to be analyzed.
If there is the possibility of the loss of a coating from a metallic substrate due to degradation, the potential degradation products from the substrate material shall be considered, as well as the coating itself. In addition, if a metallic substrate coated with a non-metallic material is to be tested, the requirements of ISO 10993-13 and/or ISO 10993-14 shall be used in order to determine the potential degradation products of the coating.
The identified and quantified degradation products form the basis for evaluation of biological response. If appropriate, toxicokinetic studies in accordance with ISO 10993-16 shall be used.
For those medical devices composed of or containing nanoscale materials, and for those instances where metallic degradation products are within the nanoscale size range (approximately 1 nm to 100 nm), the user is referred to ISO/TR 10993-22 when creating their risk assessment documents.
If the medical device is made using a metal or metal aloy designed to be absorbed by the body, the user is directed to relevant material specific standards (see bibliography) for methods and specific considerations (e.g. electrolyte, atmosphere, etc.) appropriate for this class of materials.
4.2 Prerequisites
The rates of electrochemical degradation reactions are sensitive to small variations in test conditions, instrumentation, sample conditions, and preparation. Therefore, electrochemical degradation testing shall be carried out in an appropriately equipped laboratory by experienced and qualified personnel. This includes proper maintenance and calibration of the test equipment. The methods and operating conditions of the equipment shall also be validated.
Fulfilment of electrochemical test conditions for stability, warm-up time, etc., can be demonstrated by conformance to Reference [1].ANSI/AAMI/ISO 10993-15 pdf download.