Table 1.

CMS (sodium) contents per vial (n = 3) of four different brands and elemental analysis

Parameter	150 mg colistin base activity (CBA)			Forest (UK)	Theoretical values
	X-GEN (USA)	Paddock (USA)	Atlantic (Thailand)	2 000 000 IU
Weight (mg/vial)	366.8 ± 0.80	340.6 ± 0.08	380.0 ± 5.97	159.3 ± 1.75	—
Carbon (%)	34.56	34.91	34.41	34.67	39.60
Hydrogen (%)	5.87	5.86	5.80	5.95	6.07
Nitrogen (%)	10.95	11.42	11.22	11.22	12.85
Oxygen (%)	34.26	36.83	34.46	34.91	25.69
Sulphur (%)	10.35	9.76	8.71	8.80	9.19