U.S. PHARMACOPEIA

Search USP29  
Narasin Premix
» Narasin Premix contains Narasin Granular mixed with suitable diluents and inactive ingredients. It contains not less than 90 percent and not more than 110 percent of the labeled amount of narasin.
Packaging and storage— Preserve in well-closed containers. Avoid moisture and excessive heat.
Labeling— Label it to indicate that it is for animal use only. The label bears the statement, “Do not feed undiluted.”
Identification— The retention time of the major peak for narasin A in the chromatogram of the Assay preparation corresponds to that of the Standard preparation, as obtained in the Assay.
Loss on drying 731— Dry it in vacuum at 60 for 3 hours: it loses not more than 12% of its weight.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay—
Mobile phase , Neutralized methanol, Diluent, Derivatizing reagent, Standard preparations, Resolution solution, and Chromatographic system—Proceed as directed in the Assay under Narasin Granular.
Assay preparation— Transfer about 5 g of Narasin Premix, accurately weighed, to a suitable container, add 200.0 mL of Diluent, and shake by mechanical means for 1 hour. Allow the solids to settle, and dilute an accurately measured volume of the supernatant quantitatively with Diluent to obtain a solution containing about 20 µg of narasin per mL. Pass a portion of this solution through a filter having a porosity of 0.5 µm or less, and use the filtrate as the Assay preparation.
Procedure— Proceed as directed for Procedure in the Assay under Narasin Granular. Calculate the biopotency, in mg per g, of the Narasin Premix taken to prepare the Assay preparation by the formula:
(CA + CD + IF)(VE / M),
in which M is the weight, in g, of Premix taken to prepare the Assay preparation, 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 1487
Phone Number : 1-301-816-8178