Biperiden (KL 373) lactate is non-selective muscarinic receptor antagonist that competitively binds to M1 muscarinic receptors. Biperiden (KL 373) lactate inhibits acetylcholine and enhances dopamine signaling in the central nervous system. Biperiden (KL 373) lactate has the potential for the research of Parkinson's disease and other related psychiatric disorders.