Plastic additive 18 (P-EPQ, for more details see appendix ) is a phenolic antioxidant that may be used as a stabiliser in the processing of plastic materials. It consists of seven components, all of which contribute to the efficiency of the additive, but is a product-by-process (reaction product) rather than a physical mixture. It comprises one main component and what are essentially the isomers of that component.

The members of European Pharmacopoeia (Ph. Eur.) Group 16 (the group responsible for texts on plastic materials and containers) are not certain if this additive – which is only mentioned in Ph. Eur. general chapters Polyolefins (3.1.3) and Plastic additives (3.1.13) – is still in use. In addition, from an analytical point of view, detection and quantification of the components of the additive is complex, especially in the presence of other plastic additives, and some of the components are prone to degradation (oxidation). This makes it difficult to establish reasonable quality criteria that can be measured with a standardised compendial method for products-by-process.

In view of the above, and in order to make an informed recommendation on the fate of plastic additive 18 in the Ph. Eur., the members of Group 16 are seeking your advice and assistance on this issue: to your knowledge, is plastic additive 18 still used in any plastic materials for containers for pharmaceutical use?

Feedback and supporting data can be sent to [email protected].

We understand that the kind of information requested may be confidential, but we would be most grateful for any guidance on this matter you can provide. All information received will be treated confidentially. If needed, the responses may be shared with the members of the European Pharmacopoeia Commission and with the national pharmacopeial authorities of Ph. Eur. member states. No contact details of the respondents will be shared.

Thank you in advance for your efforts in helping us ensure that the Ph. Eur. is and remains fit-for-purpose.