The subject invention provides R(+)-N-methyl-propargylaminoindan or a pharmaceutically acceptable salt thereof and a composition containing R(+)-N-propargyl-1(R)-aminoindan or a pharmaceutically acceptable salt thereof and a compound of R(+)-N-methyl-propargyl-aminoindan or a salt thereof. Also disclosed are methods of validating a batch of rasagiline for use in a pharmaceutical formulation and a method of validating a rasagiline formulation for distribution, based on the content of R(+)-N-methyl -propargyl-aminoindan or a salt thereof.
