| abstract |
Provided herein is an impurity of eletriptan, eletriptan N-oxide, (R)-5-[2- (phenylsulfonypethyl]-3-[(1-methyl-2-pyrrolidinyl-N-oxide)methyl]-1H-indole, and a process for the preparation and isolation thereof. Provided further herein is a highly pure eletriptan or a pharmaceutically acceptable salt thereof substantially free of eletriptan N-oxide impurity, processes for the preparation thereof, and pharmaceutical compositions comprising highly pure eletriptan or a pharmaceutically acceptable salt thereof substantially free of eletriptan N-oxide impurity. |