ASTM F1635 : 24

Standard Test Method for in vitro Degradation Testing of Hydrolytically Degradable Polymer Resins and Fabricated Forms for Surgical Implants

Standard Details

1.1 This test method covers in vitro degradation of hydrolytically degradable polymers (HDP) intended for use in surgical implants. It provides a detailed methodology for conditioning samples and suggests quantitative techniques for evaluating changes in properties (for example, mass, molar mass, and mechanical strength) over time.

1.1.1 For many types of HDPs, a correlation has been established between in vitro degradation per this practice and in vivo degradation for unloaded specimens (see X1.1.1).

1.2 The requirements of this test method apply to HDPs in various forms:

1.2.1 Virgin polymer resins, or

1.2.2 Any form fabricated from virgin polymer such as a semi-finished component of a finished product, a finished product, which may include packaged and sterilized implants, or a specially fabricated test specimen.

1.2.2.1 Use of this test method for conditioning virgin resins, semi-finished forms, or special test specimens may provide information that is useful for material and/or product development. However, those results are not sufficient for predicting the degradation behavior of the final, sterilized implant. Subsections 5.5, 8.2, and X1.2 provide additional guidance.

1.3 This standard provides guidance for mechanical loading or fluid flow, or both, when relevant to the device being evaluated. The specifics of loading type, magnitude, and frequency for a given application are beyond the scope of this test method.

1.4 This standard is not applicable to conditioning of polymers that degrade primarily through mechanisms other than hydrolysis (for example, enzymatic or oxidative degradation). See X1.1.1 for more information.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 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.

1.7 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.