Drugmakers should not ask excipient suppliers for metal impurity data until exposure limits are agreed according to industry group IPEC Federation.
The IPEC Federation – the umbrella organisation for regional International Pharmaceutical Excipients Councils (IPEC) – set out its position on proposed new USP chapters on metal impurities in drug excipients in a concept paper published late last week .
The organisation argues that because ICH Q3D has not yet been finalised drug companies should not be asking excipient suppliers for compliance data and that it will not be appropriate to do so until final metal impurity limits are set.
In a statement emailed to in-Pharmatechnologist.com IPEC Federation said that: “The limits are not yet locked down and the methodologies are not either - so extensive efforts could be non-value added and all need to be repeated.”
The organisation also pointed out that even when Permitted Daily Exposure (PDE) limits for metal impurities are formally agreed they will apply to the entire dosage form, rather than any individual component.
“The complication is that it is the final dosage form that must comply so solely looking at excipients and API levels is only a portion of the story – with the uncertainty in limits and methods – premature questionnaires could lead to major confusion as well as potentially misunderstood information.”
Testing in process
Excipient makers are in the process of evaluating the individual metal impurities that may be present in their excipient products and the typical levels present, however, the IPEC Federation told us that: “This is only just at the very beginning.”
In its concept paper the organisation explains even this testing may be irrelevant for customers purposes.
“Many companies have been using USP <231> in the past which is a limit test and is not specific to individual elements. Therefore, this data is not typically relevant to discussions about metal impurities down to the types of levels being discussed by the ICH Q3D EWG.”