Aclidinium Bromide is a long-acting antagonist of muscarinic (LAMAs) [1].

Aclidinium Bromide has been reported to inhibit the specific binding of [3H]-NMS to human M receptors in a dose-denpendent fasion with Ki values of 0.10±0.00nM,0.14±0.04nM, 0.14±0.02nM, 0.21±0.04nM and 0.16±0.01nM for M1, M2,M3,M4 and M5, respectively. In addition, Aclidinium Bromide has shown the great potency at endogenous M2 and M3 receptors with EC50 values of 17.4±1.1nM and 5.3±1.6nM, respectively. Apart from these, Aclidinium Bromide has been revealed to produce a concentration-dependent inhibition of acetylcholine-induced bronchoconstriction in vivo with an EC50 of ranging from 2.5 to 23.1μg/mL in anaesthetized guines pigs. Besides, Aclidinium Bromide has also been noted to inhibit the salivation in rat pilocarpine-induced sialorrhea model with an EC50 of 38μg/kg [1].

References:
[1] Gavaldà A1, Ramos I2, Carcasona C3, Calama E4, Otal R5, Montero JL6, Sentellas S7, Aparici M8, Vilella D9, Alberti J10, Beleta J11, Miralpeix M12. The in?vitro and in?vivo profile of aclidinium bromide in comparison with glycopyrronium bromide. Pulm Pharmacol Ther. 2014 Aug;28(2):114-21.