Erythromycin Estolate Capsules
Action and use
Macrolide antibacterial.
Definition
Erythromycin Estolate Capsules contain Erythromycin Estolate.
Identification
Tests
Disintegration
Maximum time, 30 minutes, Appendix XII A1. Use a 0.6% v/v solution of hydrochloric acid in place of water.
Water
The contents of the capsules contain not more than 5.0% w/w of water, Appendix IX C. Use 0.5 g.
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
1 volume of a 15% w/v solution of ammonium acetate, previously adjusted to pH 7.0, 15 volumes of ethanol (96%) and 85 volumes of chloroform.
The test is not valid unless the chromatogram obtained with solution (4) shows two clearly separated spots.
Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (5) (2.5%, with respect to erythromycin).
Assay
Dissolve a quantity of the mixed contents of 20 capsules containing the equivalent of 0.25 g of erythromycin in 400 mL of methanol and add 200 mL of sterile phosphate buffer pH 7.0 and sufficient water for injections to produce 1000 mL. Maintain the solution at 60° for 3 hours, cool, filter and carry out the microbiological assay of antibiotics for erythromycin, Appendix XIV A. The precision of the assay is such that the fiducial limits of error are not less than 95% and not more than 105% of the estimated potency.
Calculate the content of erythromycin in a capsule of average content weight, taking each 1000 IU found to be equivalent to 1 mg of erythromycin. The upper fiducial limit of error is not less than 95.0% and the lower fiducial limit of error is not more than 110.0% of the stated content.
Labelling
The quantity of active ingredient is stated in terms of the equivalent amount of erythromycin.