Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Biodistribution & persistence
Rat: phenylbutyrate highest in kidney with minimal CNS levels; taurursodiol below quantification in CNS
“Based on radioactivity, PB-related material accumulated in kidney while CNS levels were minimal (i.e., 10-fold lower than kidney); radiolabeled TUDCA-related material was below the limits of quantification in CNS tissue.”
✓ VerifiedFDA pharmacology/toxicology review, p. 46Source ↗
Modality-specific risk
High doses gave plasma exposures below human clinical exposure
“The 845 mg/kg dose is not a limit, maximum feasible, or maximum tolerated dose, and it resulted in plasma Cmax and AUC below those in humans administered the clinical dose.”
✓ VerifiedFDA pharmacology/toxicology review, p. 46Source ↗