Toxicity assessment of CBD as an active pharmaceutical ingredient (API) in an inhaler device


A pharmaceutical company.


The client is interested in using CBD (cannabidiol), the major non-psychoactive component of cannabis, in a breath-operated medical inhaler device. CBD has been associated with a range of therapeutic benefits, but the current knowledge about its toxicity is something that requires careful consideration and further research.

Project goals

To produce a toxicity review of CBD that primarily focuses on, where available, good-quality in vivo data (clinical and pre-clinical) and the inhalation route of exposure.


Bibra conducted a wide-ranging search for substance-specific toxicity data on CBD and its isomers (including in our in-house toxicity database TRACE). All the potentially relevant data was subsequently collected and assessed, including the relevant expert group reports, reviews and primary literature. The key data, derived primarily from high-quality studies with the most relevance to repeated and prolonged exposure by inhalation, were summarised in the report for a range of toxicological endpoints. This involved tabulation of the critical details from an array of oral and dermal clinical trials. The isomers of CBD and possible impurities in CBD products were also considered in this assessment.

Project outcome

Bibra provided the client with a toxicity review of CBD in consideration of its potential use as an inhaled API. The review also included information about the isomers of CBD and the possible impurities (e.g. THC) that may be present in CBD products. Furthermore, the toxicological endpoints of concern (including evidence of increased liver enzymes in clinical trials, and of potential genotoxicity and reproductive/developmental toxicity in laboratory animals) and key data gaps were identified.

Bibra project team

Richard Young
Pete Watts


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