Packaging and storage
Preserve in tight containers,protected from light.
pHá791ñ:
between 5.0and 6.0,in the suspension constituted as directed in the labeling.
Loss on drying á731ñ
Dry about 100mg,accurately weighed,in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5mm of mercury at 60

for 3hours:it loses not more than 3.0%of its weight.
Assay
Constitute Colistin Sulfate for Oral Suspension as directed in the labeling.Proceed as directed under
AntibioticsMicrobial Assays á81ñusing an accurately measured volume of this suspension,freshly mixed and free from air bubbles,diluted quantitatively with
Buffer No.6to yield a
Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard.