Oxybutynin
Summary
Persistence. It cannot be excluded that oxybutynin is persistent, due to lack of data.
Bioaccumulation. Oxybutynin has a high potential to bioaccumulate.
Toxicity. It cannot be excluded that oxybutynin is toxic, due to lack of data.
Risk. Risk of environmental impact of oxybutynin cannot be excluded, due to the lack of environmental toxicity data.
This summary information comes from fass.se.
Detailed information
General information about assessment reports
Since 2006, an Environmental Risk Assessment (ERA) for the active pharmaceutical substance shall accompany an application for a marketing authorisation in EU for a medicinal product for human use. Parts of environmental data are available in the public assessment report (PAR/EPAR for centrally approved medicines). Environmental considerations are not included in the benefit-risk assessment for human medicines. If new data emerge after approval that necessitate an update of the environmental risk assessment, a variation application (“type IB C.I.z variation”) must be submitted to the regulatory authority.
EMA’s scientific discussion
EMA’s scientific discussion for Kentera (oxybutynin) 2005-12-16.
"From the environmental risk assessment included, it seems unlikely that the transdermal patch would present a risk to the environment." No data are presented.
Fass environmental information
Fass environmental information for Ditropan (oxybutynin ) from Cheplapharm Arzneimittel GmbH (retrieved on 2026-02-24).
Excretion
"Oxybutynin is extensively metabolized in the liver; less than 0.1% of the administered dose of oxybutynin or the main metabolite N-desethyl oxybutynin are excreted unchanged via urine. N-desethyl oxybutynin is pharmacologically active and its properties are similar to those of the parent compound."
The environmental information in Fass refers to oxybutynin.
Hazard
Persistence: No data.
Bioaccumulation: "Oxybutynin has high potential for bioaccumulation, as indicated by a log Kow of 4.0 (estimated with EPI Suite Kow Win program on uncharged molecules)."
Toxicity: No data.
Risk
PEC/PNEC is based on sales data in Sweden in year 2021.
PEC = 0.002 microg/L.
PNEC = No data.
Risk of environmental impact of oxybutynin (PEC/PNEC) cannot be excluded, due to the lack of environmental toxicity data. "However, according to the European Medicines Agency guideline on environmental risk assessment of medicinal products (EMA/CHMP/SWP/4447/00), use of oxybutynin is unlikely to represent a risk for the environment, because the predicted environmental concentration (PEC) is below the action limit 0.01 µg/L."
Author: Health and Medical Care Administration, Region Stockholm