The present disclosure relates to tolperisone, or a pharmaceutically acceptable salt or hydrate thereof, with 10 ppm 2-methyl-1-(4-methylphenyl)-propenone (4-MMPPO) or less, methods of producing the same, as well as compositions related thereto. The disclosure further relates to methods of treating a subject with tolperisone under conditions that limit exposure of the subject to tolerable levels of 4-MMPPO.