U.S. PHARMACOPEIA

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Amoxicillin Oral Suspension
» Amoxicillin Oral Suspension is a suspension of Amoxicillin in Soybean Oil. It contains not less than 90.0 percent and not more than 120.0 percent of the labeled amount of amoxicillin (C16H19N3O5S).
Packaging and storage— Preserve in multiple-dose containers equipped with a suitable dosing pump.
Labeling— Label it to indicate that it is for veterinary use only.
Identification— Shake a portion of Oral Suspension with a mixture of acetone and 0.1 N hydrochloric acid (4:1) to obtain a solution containing about 1 mg of amoxicillin per mL. The solution responds to the Identification test under Amoxicillin Capsules.
Water, Method I 921: not more than 2.0%, 20 mL of a mixture of toluene and methanol (7:3) being used in place of methanol in the titration vessel.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay—
Standard preparation— Prepare as directed for Standard Preparation under Iodometric Assay—Antibiotics 425, using USP Amoxicillin RS.
Assay preparation— Using the dosing pump, deliver a number of doses of Oral Suspension, equivalent to about 250 mg of amoxicillin, to a separator containing 100 mL of hexanes, and shake vigorously. Add 140 mL of water, and shake for 5 minutes. Allow the layers to separate, and drain the lower, aqueous layer into a 250-mL volumetric flask. Repeat the extraction with two 50-mL portions of water. Combine the aqueous extracts in the volumetric flask, dilute with water to volume, and mix.
Procedure— Proceed with Oral Suspension as directed for Procedure under Iodometric Assay—Antibiotics 425, using USP Amoxicillin RS. Calculate the quantity, in mg, of amoxicillin (C16H19N3O5S) in each dose of Oral Suspension taken by the formula:
(250 / N)(F / 2000)(B I),
in which N is the number of doses taken, and the other terms are as defined therein.
Auxiliary Information— Staff Liaison : Ian DeVeau, Ph.D., Associate Director
Expert Committee : (VET05) Veterinary Drugs 05
USP29–NF24 Page 159
Phone Number : 1-301-816-8178