USP Proposes New General Chapter <668> Cured Silicone Elastomers

The USP General Chapters—Packaging and Distribution Expert Committee is proposing a new general chapter, <668> Cured Silicone Elastomers for Pharmaceutical Manufacturing and Packaging Components, based on comments received from the Pharmacopeial Forum (PF) 45(2) [Mar.—Apr. 2019] publication of <665> Plastic Materials, Components, and Systems Used in the Manufacturing of Pharmaceutical Drug Products and Biopharmaceutical Drug Substances and Products. The input deadline for the proposal is January 26, 2020.

Description of scope and application 

According to USP, this chapter "would apply to cured silicone components such as tubing, gaskets, and O-rings that are used in manufacturing operations for drug substances and drug products, as well as silicone components for pharmaceutical packaging systems". USP General Chapters with numbers >1000 are not mandatory. They are considered to be explanatory texts. However, General Chapters with numbers below 1000 are mandatory in the US.

The <668> chapter´s preliminary outline is the following: 

• Biological Reactivity
• Identification
• Physicochemical Tests:
  • Appearance
  • Acidity or alkalinity
  • Reducing Substances
  • Substances soluble in hexane
  • Phenylated compounds
  • Mineral Oils
  • Volatile matter
  • Residual peroxides
  • Platinum

The anticipated implementation timing will be determined based on stakeholder feedback (e.g. R&D scientists, contract research organizations (CRO´s), contract manufacturing organizations (CMO´s), Regulatory Affairs (RA), Quality Assurance / Quality Control (QA/QC) specialists).  The USP estimates the first proposal of <668> to be published in Pharmacopeial Forum (PF) 46(5) [Sep.–Oct. 2020].

More information can be found in USP´s posting for Cured Silicone Elastomers for Pharmaceutical Manufacturing and Packaging Components on USP´s Compendial Notices Website.