Erythromycin Ethylsuccinate Oral Suspension
» Erythromycin Ethylsuccinate Oral Suspension is a suspension of Erythromycin Ethylsuccinate containing one or more suitable buffers, colors, dispersants, flavors, and preservatives. It contains the equivalent of not less than 90.0 percent and not more than 120.0 percent of the labeled amount of erythromycin (C37H67NO13).
Packaging and storage— Preserve in tight containers, and store in a cold place.
USP Reference standards 11
USP Erythromycin RS Click to View Structure
USP Erythromycin Ethylsuccinate RS Click to View Structure
Identification— To a quantity of the Oral Suspension add a volume of methanol sufficient to yield a solution having a concentration equivalent to about 2.5 mg of erythromycin per mL. Shake this mixture by mechanical means for about 30 minutes. Centrifuge a portion of this mixture, and use the clear supernatant as the test solution. Prepare a Standard solution of USP Erythromycin Ethylsuccinate RS in methanol containing about 3 mg per mL. Apply separately 10 µL each of the test solution and the Standard solution to a suitable thin-layer chromatographic plate (see Chromatography 621) coated with a 0.25-mm layer of chromatographic silica gel mixture, and allow to dry. Place the plate in an unlined chromatographic chamber, and develop the chromatograms in a solvent system consisting of a mixture of methanol and chloroform (85:15) until the solvent front has moved about 9 cm. Remove the plate from the chamber, mark the solvent front, and allow the solvent to evaporate. Spray the plate with a mixture of dehydrated alcohol, p-methoxybenzaldehyde, and sulfuric acid (90:5:5). Heat the plate at 100 for 10 minutes, and examine the chromatograms, in which the erythromycin and succinic acid moieties appear as black-to-purple spots: the RF values of the principal spots obtained from the test solution correspond to those obtained from the Standard solution.
Uniformity of dosage units 905
for suspension packaged in single-unit containers : meets the requirements.
Deliverable volume 698: meets the requirements.
pH 791: between 6.5 and 8.5.
Assay— Proceed as directed for erythromycin under Antibiotics—Microbial Assays 81, using an accurately measured volume of Oral Suspension, freshly mixed and free from air bubbles, blended for 4 ± 1 minutes in a high-speed glass blender jar with sufficient methanol to give a stock solution containing the equivalent of about 1 mg of erythromycin per mL. Dilute this stock 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.
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Monograph Ahalya Wise, M.S.
Senior Scientific Liaison
(SM12010) Monographs - Small Molecules 1
Reference Standards RS Technical Services
USP35–NF30 Page 3088