Packaging and storage
Preserve in tight containers.
Identification
Prepare a test solution by mixing a quantity of Capsule contents with methanol to obtain a concentration equivalent to about 20 mg of erythromycin per mL. Prepare a Standard solution of
USP Erythromycin Estolate RS in methanol containing the equivalent of 20 mg of erythromycin per mL. Apply separately 3 µL of each solution to a thin-layer chromatographic plate (see
Chromatography 621) coated with a 0.25-mm layer of chromatographic silica gel. Proceed as directed in the
Identification test under
Erythromycin Delayed-Release Capsules, beginning with Place the plate in an unlined chromatographic chamber.
Disintegration 701:
30 minutes, proceeding as directed for
Hard Gelatin Capsules, except to use disks and to use simulated gastric fluid TS as the immersion fluid instead of water.
Water, Method I 921:
not more than 5.0%, 20 mL of methanol containing 10% of imidazole being used in place of methanol in the titration vessel.
Assay
Place not less than 4 Capsules in a high-speed glass blender jar with 200.0 mL of methanol, and blend for 3 minutes. Add 300.0 mL of
Buffer No. 3, and blend for 3 minutes. Allow this solution to stand at room temperature for 18 hours. Proceed as directed for erythromycin under
AntibioticsMicrobial Assays 81, using an accurately measured volume of this stock test solution diluted quantitatively with
Buffer No. 3 to yield a
Test Dilution having a concentration assumed to be equal to the median dose level of the Standard.