Packaging and storage— Preserve in tight containers.

Labeling— Label Pledgets to indicate that each Pledget is to be used once and then discarded. Label Pledgets also to indicate the volume, in mL, of Erythromycin Topical Solution contained in each Pledget, and the concentration, in mg of erythromycin per mL, of the Erythromycin Topical Solution.

USP Reference standards 11— USP Erythromycin RS.

Residual solvents 467: meets the requirements.

Other requirements— The Erythromycin Topical Solution expressed from Pledgets meets the requirements for Identification, Water, and Alcohol content under Erythromycin Topical Solution.

Topical solution assay— Proceed as directed for erythromycin under Antibiotics—Microbial Assays 81, using the solution expressed from not less than 10 Pledgets. Dilute an accurately measured volume of this 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.

Assay and minimum volume— Proceed as directed for erythromycin under Antibiotics—Microbial Assays 81, assaying 10 Pledgets individually. Transfer 1 Pledget to a suitable container, add about 50 mL of Buffer No. 3, and shake for 2 minutes. Transfer the solution so obtained to a 100-mL volumetric flask. Wash the Pledget with two 20-mL portions of Buffer No. 3, add the washings to the 100-mL volumetric flask, dilute with Buffer No. 3 to volume, and mix. Dilute an accurately measured volume of this 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. Calculate the volume, in mL, of Erythromycin Topical Solution in each Pledget taken by dividing the number of mg of erythromycin in each individual Pledget by the number of mg of erythromycin in each mL of Erythromycin Topical Solution as obtained in the Topical Solution assay. The volume of Erythromycin Topical Solution in each Pledget is not less than 90.0% of the labeled amount. If this requirement is not met, determine the volume of Erythromycin Topical Solution in each of 20 additional Pledgets. The volume of Erythromycin Topical Solution in not more than 1 of the 30 Pledgets is less than 90.0% of the labeled amount.

Expert Committee : (MDANT05) Monograph Development-Antibiotics

USP29–NF24 Page 832

Phone Number : 1-301-816-8223