Significance and Use
4.1 This guide is aimed at providing guidance for assessments and evaluations to aid in preclinical research and development of various absorbable components and devices.
4.2 This guide includes brief descriptions of various intended uses, processing conditions, assessments, and both qualitative and quantitative analyses for raw materials to finished product components.
4.3 The user is encouraged to utilize appropriate ASTM and other standards to conduct the physical, chemical, mechanical, biocompatibility, and preclinical tests on absorbable materials, device components, or devices prior to assessment in an in vivo model.
4.4 Whenever an absorbable material is mixed or coated with other substances (bioactive, polymeric, or otherwise), the physical and degradation properties of the resulting composite may differ significantly from the base polymer. Thus, unless prior experience can justify otherwise, performance characterizations described herein should be conducted on the composite construct rather than on individual components.
4.5 Assessments of absorbable materials should be performed in accordance with the provisions of the FDA Good Laboratories Practices Regulations 21 CFR 58, where feasible.
4.6 Studies to support regulatory approval for clinical or commercial use, or both, should conform to appropriate nationally adopted directives or guidelines, or both, for the development of medical devices [for example, CE approval; US-FDA Investigational Device Exemption (IDE), Pre- Market Approval (PMA), or 510K submission].
4.7 Assessments based upon data from physical, chemical, mechanical, biocompatibility, and preclinical testing models are highly valuable but carry inherent limitations. Thus, the clinical relevance of each assessment needs to be carefully considered and the user is cautioned that pre-clinical evaluations may not be predictive of human clinical performance.
Scope
1.1 This guide describes general guidelines for the chemical, physical, mechanical, biocompatibility, and preclinical assessments of implantable synthetic polymeric absorbable devices. This guide also describes evaluation methods that are potentially useful and should be considered when assessing absorbable implants or implant components.
1.2 The described evaluations may assist a manufacturer in establishing the safety and effectiveness of an absorbable implant device. This listing of assessment methods may also be utilized to assist in establishing substantial equivalence to an existing commercially marketed device. However, these polymeric material-oriented guidelines do not necessarily reflect the total needs for any particular implant application (for example, orthopedic, cardiovascular), which may require additional and potentially essential application-specific evaluations.
1.3 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 and/or semi-crystalline absorbable polymer systems.
1.4 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, α-hydroxy-polyesters). Evaluation methods suggested herein may or may not be applicable to implants formed from materials that, upon implantation, are substantially degraded through other mechanisms (for example, enzymatic action).
1.5 This guide references and generally describes various means to assess absorbable materials, components, and devices. The user needs to refer to specific test methods for additional details. Additionally, some of the recommended test methods may require modification to address the properties of a particular device, construct, or application.
1.6 Adherence to all aspects of these guidelines is not mandatory, in that assessments and tests listed within this guide are not necessarily relevant for all absorbable implant systems and applications.
1.7 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.
1.8 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).
