Being a quaternary ammonium derivative and having a high polarity, hyoscine butyl bromide slightly absorbed in the gastrointestinal tract. After application, the absorption of the drug is 8%. The average absolute bioavailability is less than 1%. After a single application of hyoscine butyl bromide inside at doses of 20-400 mg, the average peak plasma concentrations were achieved after about 2 hours and were from 0.11 to 2.04 ng / ml.
Hyoscine butyl bromide, due to its high affinity for muscarinic and nicotinic receptors, is mainly distributed in the muscle cells of the abdominal and pelvic organs, as well as in the intramural ganglia of the abdominal cavity. The connection with plasma proteins (albumin) is low and is about 4.4%. It was found that the drug (in a concentration of 1 mmol) in vitro interacts with choline transport (1.4 nmol) in epithelial cells of the human placenta.
The terminal half-life of the drug after a single oral administration at doses of 100-400 mg ranged from 6.2 to 10.6 hours. Metabolism is carried out mainly by hydrolysis of the ester bond. After ingestion, excretion of the drug occurs with feces and urine. After applying the drug inside: renal elimination is from 2 to 5%, elimination through the intestine - 90%. Renal excretion of the metabolites of hyoscine butyl bromide is less than 0.1% of the dose value. After taking the drug inside at doses of 100-400 mg, the average clearance values are from 881 to 1420 liters per minute, whereas the corresponding volumes of distribution for the same dose range vary from 6.13 to 11.3 x 105 l, which can be explained by low systemic bioavailability.
Metabolites excreted in the urine, weakly bind to muscarinic receptors, so they are not active and do not have pharmacological properties.