(1R,3S,5S)-3-(2-Hydroxy-2,2-di(thiophen-2-yl)acetoxy)-8,8-dimethyl-d3-8-azabicyclo[3.2.1]oct-6-en-8-ium Bromide is the labeled analogue of (1R,3S,5S)-3-(2-Hydroxy-2,2-di(thiophen-2-yl)acetoxy)-8,8-dimethyl-8-azabicyclo[3.2.1]oct-6-en-8-ium Bromide (H941715), an impurity in the synthesis of Tiotropium Bromide (T444850), a muscarinic receptor antagonist. Bronchodilator.