Ambroxol Theophylline-7-acetate Salt Monohydrate

In the title monohydrate salt of ambroxol (AMB) with theophylline-7-acetic acid (TAA), C13H19Br2N2O+.-C 9H9N4O4- .H2O, protonation of the secondary 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 carboxylate 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 carboxylate anion participates in an N+-H⋯O- hydrogen bond with a symmetry-related salt molecule, giving rise to a dimeric arrangement. The water molecule is linked to a carbonyl O atom of TAA and the aromatic amino group of AMB, and connects the salt molecules in the crystal at the level of the OH group of AMB.