No barium sulphate (BaSO4) particles were found in brains of rats during in vivo studies within the project NanoCare.
Since clearance in the lung starts after particle inhalation, the BaSO4 is not transported through the body of the animals [1].
Literature 
- NanoCare 2009, Final Scientific Report, ISBN 978-3-89746-108-6. (PDF-Document, 19 MB)