Certain N-formyl hydroxylamine compounds, such as N-[1-oxo-2-alkyl-3-(N-hydroxyformamido)-propyl]-(carbonylamino-aryl or -heteroaryl)-azacyclo
4-7
alkanes or thiazacyclo
4-7
alkanes or imidazacyclo
4-7
alkanes are useful in the treatment of bacterial infections. Disclosed are crystalline salts of such compounds of formula (I), wherein M is a mono- or di-valent metal; a is ½ or 1.
Certain N-formyl hydroxylamine compounds, such as N-[1-oxo-2-alkyl-3-(N-hydroxyformamido)-propyl]-(carbonylamino-aryl or -heteroaryl)-azacyclo4-7alkanes or thiazacyclo4-7alkanes or imidazacycIo4-7alkanes are useful in the treatment of bacterial infections. Disclosed are crystalline salts of such compounds of formula (I), wherein M is a mono- or di-valent metal; a is ½ or 1.