<1158> LG Polymer Implant Drug Products- Characterization Methods

Type of Posting: General Chapter Prospectus
Posting Date: 27-Mar–2026
Input Deadline: 26–Apr–2026

Current or Proposed GC Title: <1158> LG Polymer Implant Drug Products – Characterization Methods

Expert Committee: General Chapters - Pharmaceutical Dosage Forms

Suggested Audience: Suppliers and manufacturers of Implant products, testing laboratories, QA/QC specialists, and regulatory agencies.

Estimated proposal PF: Pharmacopeial Forum 53(4) [Jul-Aug. 2027]

Background and Objectives: Implant drug products made with biodegradable or non-biodegradable polymer excipients are long-acting dosage forms intended for implantation and designed to deliver drug substances over extended durations following a single administration – ranging from weeks, months or years. Drug delivery from implants can be systemic or local. This chapter will focus on biocompatible, bioabsorbable implants made with LG polymers— poly(lactide-co-glycolide) polymers

USP–NF <1> Injections and Implanted Drug Products (Parenterals)—Product Quality Tests provides the general universal and specific test framework for implants. USP-NF <1151> Pharmaceutical Dosage Forms describes implant dosage forms. This proposed General Chapter (<1158>) builds on that foundation with LG polymer implant–specific characterization and performance testing considerations.

For LG polymer implant drug products, polymer attributes (e.g., molecular weight (MW), lactide/ glycolide (L/G) ratio, end group chemistry, and related microstructural features) can influence product quality attributes and in vitro/in vivo performance, reinforcing the need for fit-for-purpose, standardized approaches for polymer and drug product characterization and performance testing.

Description of scope and application: The scope of this chapter is to provide a compendial framework for product quality and performance testing of LG polymer implant drug products. It is intended for use by manufacturers, suppliers, testing laboratories, and QA/QC specialists, and for regulatory stakeholders who evaluate implant product quality and performance.

The chapter is expected to complement existing USP–NF general chapters applicable to implant products and polymer excipients, and to identify additional implant-specific tests and considerations—particularly for solid implants.

List of potential topics:

• Introduction
• General considerations
• General drug product quality tests
• Characterization of LG polymer implant drug products
• Definitions
• Definitions and Types of LG Polymer Implant Drug Products
• Glossary

• References
  Potential topics to cover or point to other general chapters include:

• Examples of solid implants (e.g., rods, expandable devices)

• Combination presentations and delivery system components (e.g., syringes/needles/kits)

• LG Polymer Chemistry and Materials

  • Lactide: glycolide ratio, molecular weight distribution, end groups, architecture (linear)

• Residual monomers/catalysts (relevant polymer-related impurities) and water

• Manufacturing and Processing Considerations (high-level)

  • Hot-melt based processing (e.g., extrusion)

• Product Quality Tests

  • Universal Tests
  • Specific Tests
  • Performance Tests
  • Drug–Polymer and dosage form Interactions
  • Drug distribution/state, interactions affecting stability and release
  • Packaging/Delivery System Compatibility Considerations
  • Applicators for implant administration
  • Applicator compatibility and relevant interaction considerations for implant presentations
  • General considerations for implants development, selection of polymers and its chemistry, drug delivery, specific requirements, and other tests. USP is requesting early input from stakeholders on this proposal of a new General Chapter <1158> Product Quality and Performance Tests for LG Polymer Implant Drug Products, which is planned to be published for comments in the Pharmacopeial Forum.

Contact: Ravikiran.Kaja@usp.org