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
No dedicated distribution study; in rats lactitol reached mg/g levels throughout the intestine including colon
“Distribution study was not performed. However, GI distribution of lactitol was examined in a pharmacology study in rats after an oral dose of 4 g/kg. Lactitol reached in mg/g levels in all intestinal components including the colon.”
✓ VerifiedFDA multi-discipline review, p. 32Source ↗
Modality-specific risk
GLP chronic toxicity studies waived given GRAS food-additive status and ex-US experience
“GLP compliant chronic toxicity studies with lactitol were not required because of the Generally Recognized as Safe food additive status of lactitol and extensive ex-US experience with the drug.”
✓ VerifiedFDA multi-discipline review, p. 36Source ↗