Health risk assessment of di-n-butyl phthalate as a potential leachable in an eye ointment


A pharmaceutical company in the far East.


The company had commissioned extractables studies on a container-closure system (CCS) intended to store an eye ointment. The only extractable detected was di-n-butyl phthalate (DBP).

Project goals

Bibra was asked to assess the possible health risks that might arise if DBP were to leach into the ointment during storage, and be administered into patients’ eyes. The client advised on the amount of ointment to be applied daily and the treatment duration.


Bibra estimated the “worst-case” DBP exposure scenario and carried out a health risk assessment (of all relevant endpoints i.e. local irritation and systemic toxicity including sensitisation, genotoxicity, carcinogenicity, reproductive/developmental toxicity, etc). For this very well-studied phthalate, Expert Group reviews and opinions served as key sources of toxicity data, supported by a REACH dossier and the newer primary literature.

Project outcome

Bibra’s health risk assessment report clearly illustrated that the DBP would not pose any significant risks to patient health, even if it were to be a genuine leachable.

Bibra project team

Charlie Johnson

Pete Watts


Extractables and Leachables

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