[wombatpm]

I believe the studies were done with a single isomer, which was safe and is still available. The racemic mixture was sold commercially but never tested until later. IIRC the bench top process produced a single isomer, but the scaled up process messed with the chirality producing the racemic mixture.

[lychrel]

Yeah this was the real problem with Thalidomide. It pops up as an example of "things to consider" in DD textbooks.