Synthetic biodegradable polyesters for implantable controlled-release devices

ABSTRACT

Introduction

Implantable devices can be designed to release drugs to localized regions of tissue at sustained and reliable rates. Advances in polymer engineering have led to the design and development of drug-loaded implants with predictable, desirable release profiles. Biodegradable polyesters exhibit chemical, physical, and biological properties suitable for developing implants for pain management, cancer therapy, contraception, antiviral therapy, and other applications.

Areas covered

This article reviews the use of biodegradable polyesters for drug-loaded implants by discussing the properties of commonly used polymers, techniques for implant formulation and manufacturing, mechanisms of drug release, and clinical applications of implants as drug delivery devices.

Expert opinion

Drug delivery implants are unique systems for safe and sustained drug release, providing high bioavailability and low toxicity. Depending on the implant design and tissue site of deployment, implants can offer either localized or systemic drug release. Due to the long history of use of degradable polyesters in medical devices, polyester-based implants represent an important class of controlled release technologies. Further, polyester-based implants are the largest category of drug delivery implants to reach the point of testing in humans or approval for human use.

KEYWORDS:

• Polyester
• controlled release
• biodegradable implants
• polymeric implants

Article highlights

• The manuscript reviews the development of implantable, degradable drug delivery devices.

• The manuscript describes the unique advantages of biodegradable polyesters for implant fabrication.

• The report compiles information on polyester implants that have been tested in humans or approved for human use.

• The article provides insight into the current challenges in developing degradable implants.

• The article discusses the synthesis, degradability, and applications of PLA, PLGA, PCL, PVL, PDO, PPDL, and P(PDL-co-DO) relevant to implantable drug delivery devices.

• This box summarizes key points contained in the article.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This publication was prepared with support from subagreements funded by Family Health International (FHI 360) under Cooperative Agreements No. AID-OAA-A-15-00045 and 7200AA20CA0016 funded by the U.S. Agency for International Development and a subagreement funded by FHI Partners under Agreement No. OPP1200867 funded by the Gates Foundation. The content of this publication does not necessarily reflect the views, analysis or policies of FHI 360, FHI Partners, USAID or the Gates Foundation, nor does any mention of trade names, commercial products, or organizations imply endorsement by FHI 360, FHI Partners, USAID or the Gates Foundation. We are grateful to all of our partners at FHI 360, USAID, and the Gates Foundation, who have improved our understanding of this field through their helpful discussions.