AMBROXOL THEOPHYLLINE-7-ACETATE SALT MONOHYDRATE

In the title monohydrate salt of ambroxol (AMB) with theophylline-7-ac etic acid (TAA), C13H19Br2N2O+.- C9H9N4O4-.H2O, protonation of the sec ondary amino group of AMB takes place. An N+-H ... O- hydrogen bond is established between the protonated N atom and an O atom of the carbox ylate anion, the same atom as is involved in an N-H ... O interaction with the aromatic amino group of the cation, The other O atom of the c arboxylate anion participates in an N+-H ... O- hydrogen bond with a s ymmetry-related salt molecule, giving rise to a dimeric arrangement. T he water mol ecule is linked to a carbonyl O atom of TAA and the aroma tic amino group of AMB, and connects the salt molecules in the crystal at the level of the OH group of AMB.