Packaging and storage—
Preserve in tight containers.
Identification—
Prepare a test solution by mixing a quantity of finely ground Capsule contents with methanol to obtain a concentration of about 2.5 mg of erythromycin per mL. Prepare a Standard solution of
USP Erythromycin RS in methanol containing 2.5 mg per mL. Apply separately 10 µL of each solution to a thin-layer chromatographic plate (see
Chromatography 
621
) coated with a 0.25-mm layer of chromatographic silica gel. Place the plate in an unlined chromatographic chamber, and develop the chromatogram in a solvent system consisting of a mixture of methanol and chloroform (85:15) until the solvent front has moved about 7 cm. Remove the plate from the chamber, mark the solvent front, and allow the solvent to evaporate. Spray the plate with a mixture of alcohol,
p-methoxybenzaldehyde, and sulfuric acid (90:5:5). Heat the plate at 100
for 10 minutes, and examine the chromatogram, in which erythromycin appears as a black-to-purple spot: the
RF value of the principal spot obtained from the test solution corresponds to that obtained from the Standard solution.
Drug release, Method B 724—
Apparatus 1:
50 rpm.
Times:
60 minutes for Acid Stage; 60 minutes for Buffer Stage.
Procedure—
Transfer the contents of 1 Capsule to the apparatus. Proceed as directed for
Acid Stage, 900 mL of 0.06 N hydrochloric acid being placed in the vessel instead of 1000 mL of 0.1 N hydrochloric acid, and the apparatus operated for 60 minutes instead of 2 hours. Do not perform an analysis at the end of the
Acid stage. Continue as directed for
Buffer Stage, 900 mL of the pH 6.8 phosphate buffer being used instead of 1000 mL. Determine the amount of C
37H
67NO
13 dissolved after 120 minutes by assaying a filtered portion of the solution under test as directed under
Antibiotics—Microbial Assays 81.
Tolerances—
Not less than 80% (Q) of the labeled amount of C37H67NO13 is dissolved in 120 minutes.
Dissolution 711—
Proceed as directed for
Procedure for
Method B under
Apparatus 1 and Apparatus 2, Delayed-Release Dosage Forms.
Apparatus 1:
50 rpm.
Times:
60 minutes for Acid Stage; 60 minutes for Buffer Stage.
Procedure—
Transfer the contents of 1 Capsule to the apparatus. Proceed as directed for
Acid Stage, 900 mL of 0.06 N hydrochloric acid being placed in the vessel instead of 1000 mL of 0.1 N hydrochloric acid, and the apparatus operated for 60 minutes instead of 2 hours. Do not perform an analysis at the end of the
Acid stage. Continue as directed for
Buffer Stage, 900 mL of the pH 6.8 phosphate buffer being used instead of 1000 mL. Determine the amount of C
37H
67NO
13 dissolved after 120 minutes by assaying a filtered portion of the solution under test as directed under
Antibiotics—Microbial Assays 81.
Tolerances—
Not less than 80% (Q) of the labeled amount of C37H67NO13 is dissolved in 120 minutes.
(Official April 1, 2006)
Water, Method I 921:
not more than 7.5%, 20 mL of methanol containing 10% of imidazole being used in place of methanol in the titration vessel.
Assay—
Proceed as directed under
Antibiotics—Microbial Assays 81, using not less than 5 Capsules blended for about 3 minutes in a high-speed glass blender jar containing 200 mL of methanol. Add 300 mL of
Buffer No. 3, and blend again for about 3 minutes. Dilute an accurately measured volume of 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.
Auxiliary Information—
Staff Liaison :
Brian D. Gilbert, Ph.D., Scientist
Expert Committee : (MDANT05) Monograph Development-Antibiotics
USP29–NF24 Page 829
Pharmacopeial Forum : Volume No. 31(1) Page 154
Phone Number : 1-301-816-8223
