Also available in 1 mL, 10 mg, 25 mg, 50 mg, 500 mg and bulk. Please contact Fisher for quotes. Tiotropium bromide (BA679 BR) is a long-acting, 24 hour, anticholinergic bronchodilator used in the management of chronic obstructive pulmonary disease (COPD). Tiotropium is a muscarinic receptor antagonist, on topical application it acts mainly on M3 muscarinic receptors located in the airways to produce smooth muscle relaxation, thus producing a bronchodilatory effect. Purity 99.09%