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 2.0%of its weight.
Assay
Assay preparation 1
(where it is labeled on a weight basis)Dissolve about 3g of Powder in an accurately measured volume of 0.01Nhydrochloric acid sufficient to obtain a solution containing not less than 1000µg of chlortetracycline hydrochloride (C22H23ClN2O8·HCl)per mL.
Assay preparation 2
(where the label states the amount of chlortetracycline in the immediate container)Transfer the contents of 1container of Powder to an accurately measured volume of 0.01Nhydrochloric acid sufficient to obtain a solution containing not less than 1000µg of chlortetracycline hydrochloride (C22H23ClN2O8·HCl)per mL.
Procedure
Proceed with Powder as directed for chlortetracycline under
AntibioticsMicrobial Assays á81ñ,using an accurately measured volume of
Assay preparationdiluted quantitatively and stepwise with water to yield a
Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard.