New Guide for Identification of Considerations and Risks Associated with the Manufacturing and Use of Absorbable Polymer Based Implants
1. Scope
1. Scope
1.1 This guide is intended to assist primarily in the recognition of potential risks considered unique, less obvious, or particularly important or significant to hydrolysable absorbable polymeric materials, devices, or device components intended for implantation in the human body with optional provision of some additional analysis, estimation, evaluation of those risks included, where appropriate.
1.2 This guide does not purport to address all potential risks, especially those associated with the design of implantable devices utilizing an absorbable polymer.
1.3 This guide has been generated with principal emphasis on the evaluation of devices formed from synthetic polymers that degrade in vivo primarily through hydrolysis (for example, a-hydroxy-polyesters that undergo bulk degradation). Considerations, risks, and evaluation methods suggested herein for these polylactone-based polyesters may or may not be applicable to implants formed from materials that, upon implantation, are substantially degraded through other mechanisms (for example, enzymatically induced bio-erosive or oxidative degradation). For absorbable polymers that do not degrade through bulk hydrolysis, users of this document need to independently conduct their own additional research/investigation of the potential risks that accompany enzymatic, oxidative, or other primarily surface-interactive degradation mechanisms.
1.4 This guide is not limited in applicability to the most common absorbable polymers, but rather to inform the user of common risks associated with the use of any hydrolytically degradable polymer as part of a medical device. Examples of the most common hydrolytically degradable polymeric medical devices are based on a-hydroxy-polyesters, including polylactide, polyglycolide, poly(lactide-co-glycolide), and polydioxanone. Other examples of hydrolytically-degradable polymers include polycaprolactone, poly(diol citrate). Examples of other classes of polymers that may be hydrolytically degradable include polyanhydrides, polyorthoesters, polyurethanes, and polyesteramides.
1.5 These polymeric material-oriented guidelines do not reflect the total needs for any particular implant application (for example, orthopedic, cardiovascular, sutures, and dermal fillers), which likely require additional and potentially essential application-specific requirements, evaluations, and manufacturing considerations.
1.6 The risks described in this guide may also be applicable to absorbable ceramics or absorbable metals, but evaluation methods specific for these types of materials will not be covered.
1.7 This guide is intended to cover all forms of absorbable polymeric components and devices, including solid (for example, injection-molded) and porous (for example, fibrous) forms. This guide is also intended to cover devices fabricated from amorphous, semi-crystalline, cross-linked, and all other absorbable polymer systems.
1.8 Adherence to all aspects of these guidelines is not mandatory, in that the described considerations, assessments, and tests listed within this guide are not necessarily relevant for all absorbable implant systems and applications.
1.9 Risks associated with combination of absorbable polymers with bioactive agents (drug delivery) - Absorbable polymers used as a matrix to control the in vivo release of bioactive agents (drugs, antimicrobials, and so forth) may be evaluated according to many of the methods described herein. However, additional test methods not covered by this guide will likely be needed to evaluate a bioactive agent’s composition, loading, release kinetics, safety, and efficacy.
1.10 Composites of absorbable polymers with ceramics and/or metals may be evaluated according to many of the methods described herein. However, additional test methods not covered by this guide will likely be needed to evaluate the composite’s other component(s).
1.11 Risk considerations regarding the cost benefit of a device are outside the scope of this guide.
1.12 Units - The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.
1.13 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 and health practices and determine the applicability of regulatory limitations prior to use.
Numerous standards exist for implantable absorbable polymeric materials and general absorbable device guidance can be found in ASTM F2902. However, little guidance exists that underscores the risks involved in the numerous steps needed to successfully bring a reliable implantable absorbable implant device to market, which range from raw material quality to clinical implant design and post-market surveillance. This standard, which will cite existing standards whenever possible, is intended to uniquely provide a general overview of the steps to market and any related non-obvious or critical risks that may be unique to implants composed of absorbable materials.
