It is a selective M₂ muscarinic receptor antagonist.

Its muscarinic-blocking activity in narcotized rats (40 mg (i.p.) ethaminal sodium) as compared with the Atropine activity (100%):
- on M₂ receptors (heart), 135 %, ED50 = 0.023 μM/kg.
- on M4 receptors (intestine), 1.9 %, ED50 = 0.9 μM/kg.
- on M3 receptors (salivary glands), 0.1 %, ED50 = 14.7 μM/kg.
- on the isolated rat intestine, for the antagonism to the spasmogenic effect due to Carbocholine: EC50 = 5.1x10^-8 g/ml.

Store at +4°C, in a dark place.
For experiments in vivo: 0.005 to 40-60 mg/kg.
Solution for use: from 10^-9 g/ml: Dissolve 10 mg in 0.2 ml of 0.3 %HCl (0.01 N HCl), heat up to 80-90 °C mixing, then dilute with distilled water up to the required concentration.

For research use only — not intended for food, diagnostic or therapeutic use