This invention relates to a macrolide composition more particularly an amorphous form (Form III) of 3R 4S 5S 6R 7R 9R 11S 12R 13S 14R 6 [(2S 3R 4S 6R) 4 dimethylamino 3 hydroxy 6 methyloxan 2 yl]oxy 14 ethyl 7 12 13 trihydroxy 4 [(2R 4R 5S 6S) 5 hydroxy 4 methoxy 4 6 dimethyloxan 2 yl]oxy 10 (2 methoxyethoxymethoxyimino) 3 5 7 9 11 13 hexamethyl 1 oxacyclotetradecan 2 one or roxithromycin characterised by the absence of peaks in the infra red spectrum of amorphous (Form Ill) of roxithromycin at 3577.15 3526.03 3465.27 and 3276.24 cm 1 relative to the infra red spectrum of the prior art roxithromycin raw material displaying peaks at 3577.15 3526.03 3465.27 and 3276.24 cm 1 and further characterised by an increased solubility of at least 50% over prior art anhydrous and monohydrated roxithromycin in acetate buffer (pH 4.5) phosphate buffer (pH 6.8) and water.
