Rivastigmine carbamate impurity (3-Nitrophenyl ethyl(methyl)carbamate) is a byproduct found in Rivastigmine, which is recognized as a powerful and orally active inhibitor of cholinesterase (ChE). Specifically, Rivastigmine effectively inhibits both butyrylcholinesterase (BChE) and acetylcholinesterase (AChE), with IC50 values of 0.037 μM and 4.15 μM, respectively.