Revised Ph. Eur. Chapter on Rubber Closures

Following the draft chapter 3.2.9. Rubber closures for containers for aqueous parenteral preparations, for powders and for freeze-dried powders (Pharmeuropa 33.2) the final version has been published in the European Pharmacopoeia (Ph. Eur.) 11.1. The supplement is now available and will become applicable as of 1 April 2023.

The general revision of the chapter 3.2.9. includes changes to the following sections:

• Definition and Scope: Rubber closures include stoppers for vials as well as needle shields and plunger stoppers for syringes, etc. The use of natural rubber latex is not permitted but dry natural rubber may be used, since the allergens are removed during processing.
• Identification: IR is maintained as the main and basic technique for rubber identification. The status of the Total Ash test changed from always necessary to only possibly needed and complementary.
• Extractable Heavy Metals: The test has been deleted to align with ICH Q3D and Ph. Eur. policy on Elemental Impurities. However, Extractable Zinc testing is still required.
• Functional Tests: The introduction has been expanded to clarify cases in which the tests for penetrability, fragmentation and self-sealing may have to be adapted or can be omitted.
• Fragmentation: The specific testing procedure for closures used for dry preparations has been removed.

Furthermore, it has been clarified that the manufacturer of the pharmaceutical preparation must obtain assurance from the supplier that the composition of the closure does not vary and that it is identical to the one used during compatibility testing. When the supplier informs the pharmaceutical manufacturer about changes made to the composition, "it is recommended to carry out a risk assessment to determine whether it is necessary to repeat the compatibility testing".