Article: Q&A on the USP <661> changes with Smithers Rapra expert Michael Creese

On May 1st 2016, the U.S. Phamacopeial Convention published the revised USP <661> with two additional chapters concerning plastic material characterisation for medical packaging systems.

Smithers Rapra expert Michael Creese provides an overview of how these changes affect stakeholders in the pharmaceutical industry supply chain.

What are these amendments, and what do they cover?

There are two separate chapters which were added to the May 2016 revision of USP <661>:

  • Plastic Materials of Construction <661.1>
  • Plastic Packaging Systems for Pharmaceutical Use <661.2>

Plastic Materials of Construction <661.1> determines whether a material has been well-characterised, for its intended use, and is designed to ensure that the material characteristics match the relevant performance requirements.

Plastic Packaging Systems for Pharmaceutical Use <661.2> provides test methods and standards for plastic packaging systems.

What tests would Smithers Rapra perform to identify the material characteristics as required in <661.1> and <661.2>?

The testing programme undertaken would depend on the specific polymer used in the packaging system.

For<661.1> it may include any of the following tests (or a combination of them):

  • Biological reactivity
  • IR
  • Thermal analysis (DSC)
  • Extraction (possible solvents: water, toluene, alcohol)
    • Acidity or alkalinity
    • Absorbance
    • TOC
  • Metals (ICP)
  • LC (as required for the additive composition)
  • TLC

For <661.2> the focus is on suitability for use with respect to patient safety, and therefore the programme would focus on bio-reactivity testing and water extraction (acidity or alkalinity, absorbency, TOC).

What do these changes mean for packaging which is currently in use?

If the packaging system is used with a pharmaceutical product that is currently on the market, it does not require testing to the new requirements – as they will have already gained regulatory approval. The new changes will only affect packaging systems which have not yet gained regulatory approval.

If modifications are made to an existing packaging system, will it have to undergo regulatory submission?

This depends on what modifications have been made.

If a new material has been introduced, or if a material has changed then the packaging system will have to be re-tested.

If the packaging system is changed in a way that does not alter its materials, then it does not need testing.

What if an existing packaging system is used for a different packaging system; will this have to be re-tested and submitted?

This varies depends on the conditions of use. It won’t have to be tested if:

  • The dosage form and conditions of use are similar
  • The dosage form and conditions of use are moving from a ‘high risk’ to a ‘low risk’ dosage form

However if the dosage form or conditions of use are moving from a ‘low risk’ to a ‘high risk’ dosage form, then the packaging system will need to be tested. This is because the <661.1> materials testing for ‘high risk’ dosage forms is more extensive than those for ‘low risk’.

Are we expecting any additional changes or amendments?

Additional chapters are currently under review; 661.3 (Plastic Systems Used for Manufacturing Pharmaceutical Products) and 661.4 (Plastic Medical Devices Used to Deliver or Administer Pharmaceutical Products) will address the material characterisation of plastics used in the manufacturing process and medical devices.  


For more information on how the expert team at Smithers Rapra can help with your regulatory testing and submissions, contact us today.

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