Packaging and storage—
Preserve in tight containers, and store at controlled room temperature.
Identification—
Prepare a test solution containing the equivalent of 4 mg of amoxicillin per mL by adding 0.1 N hydrochloric acid to powder from Amoxicillin Capsules. Prepare a Standard solution of
USP Amoxicillin RS in 0.1 N hydrochloric acid containing 4 mg per mL. Use within 10 minutes after preparation. Apply separately 5 µL of each solution on a thin-layer chromatographic plate coated with a 0.25-mm layer of chromatographic silica gel mixture (see
Chromatography 
621
). Place the plate in a suitable chromatographic chamber, and develop the chromatogram in a solvent system consisting of a mixture of methanol, chloroform, water, and pyridine (90:80:30:10). When the solvent front has moved about three-fourths of the length of the plate, remove the plate from the chamber, and dry with warm air for 10 minutes. Locate the spots on the plate by spraying lightly with a solution of ninhydrin in alcohol containing 3 mg per mL, and dry at 110
for 15 minutes: the
RF value of the principal spot obtained from the test solution corresponds to that obtained from the Standard solution.
Dissolution 711—
Medium:
water; 900 mL.
Apparatus 1:
100 rpm, for Capsules containing 250 mg.
Apparatus 2:
75 rpm, for Capsules containing 500 mg.
Time:
60 minutes.
Procedure—
Determine the amount of C
16H
19N
3O
5S dissolved by employing UV absorption at the wavelength of maximum absorbance at about 272 nm on filtered portions of the solution under test, suitably diluted with water, if necessary, in comparison with a Standard solution having a known concentration of
USP Amoxicillin RS in the same
Medium.
Tolerances—
Not less than 80% (Q) of the labeled amount of C16H19N3O5S is dissolved in 60 minutes.
Assay—
Diluent, Mobile phase, Standard preparation, and Chromatographic system—
Prepare as directed in the
Assay under
Amoxicillin.
Assay preparation—
Remove, as completely as possible, the contents of not fewer than 20 Capsules, and weigh accurately. Mix the combined contents, and transfer an accurately weighed quantity, equivalent to about 200 mg of anhydrous amoxicillin, to a 200-mL volumetric flask, add Diluent to volume, and mix. Sonicate if necessary to ensure complete dissolution. Pass a portion of this solution through a suitable filter having a 1-µm or finer porosity, and use the filtrate as the Assay preparation. Use this solution within 6 hours.
Procedure—
Proceed as directed for
Procedure in the
Assay under
Amoxicillin. Calculate the quantity, in mg, of amoxicillin (C
16H
19N
3O
5S) in the portion of Capsules taken by the formula:
0.2CP(rU / rS),
in which the terms are as defined therein.
Auxiliary Information—
Staff Liaison :
Brian D. Gilbert, Ph.D., Scientist
Expert Committee : (MDANT05) Monograph Development-Antibiotics
USP29–NF24 Page 158
Pharmacopeial Forum : Volume No. 30(5) Page 1583
Phone Number : 1-301-816-8223
