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.
Assay
Diluent, Mobile phase, Neutralized methanol, Derivatizing reagent, Resolution solution, Standard preparations, 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 quantitatively dilute an accurately measured volume of the supernatant 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 0.5-µm or finer porosity, 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, in the portion of Narasin Premix taken by the formula:
(0.001)(CA FA + CD +I FD +I)(VE / M)
in which M is the weight, in g, of Narasin Premix taken to prepare the Assay preparation; and the other terms are as defined therein.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 3999
Pharmacopeial Forum: Volume No. 32(1) Page 126
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