This post is a shortened version of a longer article available on our website.
Why Test Pharmaceutical Plastics?
The United States Pharmacopoeia (USP) has set analytical standards to ensure polymer materials do not impact human health regardless of how or when those materials come in contact with a pharmaceutical product. Plastics may contain residues from the polymerization process and/or additives of concern such as antioxidants, stabilizers, lubricants, plasticizers, and colorants. To assess safety, in-depth analytical investigations are required for pharmaceutical plastics.
In 2016, the USP expanded the analytical standards in chapter 661 to further support packaging safety; these new chapters are USP 〈661.1〉, USP 〈661.2〉, and USP 〈665〉. USP 661.1 and USP 661.2 become official on December 1, 2025, but early adoption is allowed and encouraged. USP 665 becomes official on May 1, 2026.
USP 661 “Plastic Packaging Systems and Their Materials of Construction”
USP 661 formally assesses “plastic articles (materials, components, and systems) used to package medical articles (pharmaceuticals, biologics, and dietary supplements)”. Testing includes:
- Identification and characterization tests
- Infrared Spectroscopy (IR)
- Differential Scanning Calorimetry (DSC)
- Physicochemical tests
- Extraction with water, alcohol, and hexane
- Heavy Metals assessment on water extraction
- Nonvolatile Residue (NVR) on all extractions
- Residue on Ignition (ROI) following certain NVR results
- Buffering Capacity for liquid containers
- Biological testing per USP 〈87〉 for high risk applications (inhalation, parenteral, ophthalmics)
- Additional polymer-specific tests
USP 661.1 “Plastic Materials of Construction”
USP 661.1 introduces more rigorous standards and testing to demonstrate that polymer raw material is well-characterized and suitable for its intended use. Testing includes:
- Identification and characterization tests
- Infrared Spectroscopy (IR)
- Differential Scanning Calorimetry (DSC)
- Physicochemical tests
- Water extraction
- UV Absorbance
- Acidity/Alkalinity using indicators
- Total Organic Carbon (TOC)
- Biological testing per USP 〈87〉 for high risk applications
- Material-specific tests for plastic additives and/or related substances
USP 661.2 “Plastic Packaging Systems for Pharmaceutical Use”
USP 661.2 tests “plastic packaging components and systems used for packaging final drug products”. Testing includes:
- Physicochemical tests
- Water extraction
- Appearance (color and clarity of extraction)
- UV Absorbance
- Acidity/Alkalinity using indicators
- Total Organic Carbon (TOC)
- Biological testing per USP 〈87〉 for high risk applications
- Spectral Transmission if light protection is necessary
- Two additional tests for PET and PETG
- Chemical Suitability Assessment
USP 665 “Plastic Components and Systems Used to Manufacture Pharmaceutical Drug Products and Biopharmaceutical Drug Substances and Products”
USP 665 (formerly drafted as 661.3) emphasizes analysis of organic extractables in plastic manufacturing materials and components used in the conversion of raw starting materials into active pharmaceutical ingredients (APIs), drug substances, and drug products. Testing includes:
- Nonvolatile Residue (NVR)
- UV Absorbance
- Organic extractables profiling (USP 1663)
USP Pharmaceutical Plastics Testing at EKG Labs
With the increasing influence of the USP on polymers in the pharmaceutical industry, new chapters, and frequent changes, it can be difficult to stay on top of the latest recommendations. Fortunately, EKG Labs takes pride in keeping up-to-date with the latest USP revisions and is able to provide appropriate consulting and analytical services for companies seeking to conform to USP standards. Our experience working with polymer materials and active ingredients uniquely positions us an industry leader in packaging testing. Our team understands the complex interactions between pharmaceutical products and polymers, and we have years of experience guiding companies through the analytical portion of their product development.
Through our considerable experience in regulatory compliant polymer analysis, we are also able to provide guidance on the Chemical Safety Assessments required in the expanded guidance chapters 1663, 1664, and 1665.
EKG Labs supports USP 661, 661.1, 661.2, and 665 analytical testing. To find out more about our pharmaceutical plastic testing, contact us at info@ekglabs.com or at 810-354-5229.
