Which diluents can be used to reconstitute Promixin (colistimethate sodium) 1 million IU powder for nebuliser solution?

Reconstitute Promixin 1 million IU with Water for Injections (hypotonic), a 50:50 mixture of Water for Injections and 0.9% sodium chloride (isotonic), or 0.9% sodium chloride (hypertonic), using the volume specified by the nebuliser instructions, normally no more than 4 ml, and swirling gently to avoid frothing.