ASTM F3268-18

5.1 This standard provides an itemization of potential 5.2 It is recognized that not all test methods will be meaningful for every situation. In addition, some methods carry different potential than others regarding their relative approximation to the in vivo conditions within which actual use is to occur. As a result, some discussion and ranking of the relevance of the described methods is provided by this guidance.

5.3 It should be noted that degradation of absorbable metals is not linear. Thus, precautions should be taken that evaluations of the degradation profile of a metal or metal device are appropriately adapted to reflect the varying stages and rates of degradation. Relevant factors can include the amount or percentage (%) of tissue coverage of the implanted device and the metabolic rate of surrounding tissue, which is not necessarily accompanied by a high perfusion rate.

5.4 It is recognized that in vivo environments will impart specialized considerations that can directly affect the corrosion rate, even when compared with other 5.5 Within the evaluation of absorbable metals, rate uniformity is considered to be the principle concern and design goal. The recognized primary value for the herein described 5.6 Once a suitable level of device corrosion consistency has been established (either directly or historically), static and/or dynamic fatigue testing can then be undertaken, if needed, to further enhance the understanding of the corrosion process within the context of the device’s overall design and its intended application/use.

5.7 Depending on the intended application, appropriate levels of implant loading may range from minimal to severe. Thus, this standard does NOT directly address the appropriate level of loading of absorbable metallic devices, guidance for which may be found in documents specific to the intended implant application and the design requirements for the product.

5.8 This standard does NOT directly address dynamic fatigue testing of absorbable metallic devices.

1.1 The purpose of this standard is to outline appropriate experimental approaches for conducting an initial evaluation of the in vitro degradation properties of a device or test sample fabricated from an absorbable metal or alloy.

1.2 The described experimental approaches are intended to control the corrosion test environment through standardization of conditions and utilization of physiologically relevant electrolyte fluids. Evaluation of a standardized degradation control material is also incorporated to facilitate comparison and normalization of results across laboratories.

1.3 The obtained test results may be used to screen materials and/or constructs prior to evaluation of a more refined fabricated device. The described tests may also be utilized to define a device’s performance threshold prior to more extensive 1.4 This standard is considered to be applicable to all absorbable metals, including magnesium, iron, and zinc-based metals and alloys.

1.5 The described tests are not considered to be representative of in vivo conditions and could potentially provide a more rapid or slower degradation rate than an absorbable metal’s actual 1.6 This standard only provides guidance regarding the 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.