The invention provides a crystalline 1, 2-ethanedisulfonic acid salt of biphenyl-2-ylcarbamic acid 1-[2-(2-chloro-4-{[(R)-2-hydroxy-2-(8-hydroxy-2-oxo-1, 2-dihydroquinolin-5-yl)ethylamino]methyl}-5-methoxyphenylcarbamoyl)ethyl]piperidin-4-yl ester or a solvate thereof. This invention also provides pharmaceutical compositions comprising such a salt or prepared using such a salt; processes and intermediates for preparing such a salt; and methods of using such a salt to treat a pulmonary disorder.