Assay
Assay preparation 1
Dissolve an accurately weighed quantity of Sterile Erythromycin Lactobionate quantitatively in methanol to obtain a stock solution containing the equivalent of about 10 mg of erythromycin per mL. Dilute this stock solution quantitatively with
Buffer No. 3 (see
Media and Diluents under
AntibioticsMicrobial Assays 81) to obtain a
Test Dilution having a concentration assumed to be equal to the median dose level of the Standard.
Assay preparation 2
(where it is packaged for dispensing and is represented as being in a single-dose container)Constitute Sterile Erythromycin Lactobionate in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Withdraw all of the withdrawable contents, using a suitable hypodermic needle and syringe, and dilute quantitatively with Buffer No. 3 to obtain a Test Dilution having a concentration assumed to be equal to the median dose level of the Standard.
Assay preparation 3
(where the label states the quantity of erythromycin in a given volume of constituted solution)Constitute 1 container of Sterile Erythromycin Lactobionate in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Dilute an accurately measured volume of the constituted solution quantitatively with Buffer No. 3 to obtain a Test Dilution having a concentration assumed to be equal to the median dose level of the Standard.