Monensin Granulated
»Monensin Granulated contains Monensin mixed with suitable diluents,carriers,and inactive ingredients prepared in a granulated form that is free-flowing and free from aggregates.It may contain added Monensin Sodium.It contains not less than 140mg of monensin per g.
Packaging and storage— Preserve in well-closed containers.Avoid moisture and excessive heat.
Labeling— Label it to indicate that it is for veterinary use only.Label it also to state that it is for manufacturing,processing,or repackaging.
Identification— The chromatogram of the Assay preparationobtained as directed in the Assayexhibits a major peak for monensin Aand a minor peak for monensin B,the retention times of which correspond to those exhibited in the chromatogram of the Standard preparation,obtained as directed in the Assay.
Loss on drying á731ñ— Dry it in vacuum at 60for 2hours:it loses not more than 10%of its weight.
Content of monensin Aand Bactivity— Using the results of the calculations in the Assay,calculate the percentage of monensin Aactivity in the Monensin Granulated under test by the formula:
100A/P,
in which Ais the potency,in µg per mg,of monensin Ain the Monensin Granulated under test,as determined in the Assay,and Pis the potency,in µg of monensin,in each mg of the Monensin Granulated under test,as determined in the Assay:not less than 90%is found.Calculate the percentage of monensin Aactivity plus monensin Bactivity in the Monensin Granulated under test by the formula:
100(A+B)/P,
in which Bis the potency,in µg per mg,of monensin Bin the Monensin Granulated under test,as determined in the Assay,and the other terms are as defined above:not less than 95%is found.
Assay—
Mobile phase,Neutralized methanol,Diluent,Derivatizing reagent,Standard preparation,Resolution solution,andChromatographic system— Proceed as directed in the Assayunder Monensin.
Assay preparation— Transfer about 5g of Monensin Granulated,accurately weighed,to a 250-mLflask,add 200.0mLof Diluent,and shake by mechanical means for 1hour.Allow the solids to settle,and dilute an accurately measured volume of the supernatant quantitatively with Diluentto obtain a solution containing about 20µg of monensin per mL.
Procedure— Proceed as directed for Procedurein the Assayunder Monensin.Calculate the quantity,in mg,of monensin Ain each g of the Monensin Granulated taken by the formula:
(CFD/100,000W)(rU/rS),
in which Cis the concentration,in µg per mL,of monensin activity in the Standard preparation,based on the quantity of USP Monensin Sodium RStaken,its designated potency,in µg per mg,and the extent of dilution,Fis the designated percentage of monensin Ain USP Monensin Sodium RS,Dis the dilution factor used in preparing the Assay preparation,Wis the quantity,in g,of Monensin Granulated taken to prepare the Assay preparation,and rUand rSare the monensin Apeak responses obtained from the Assay preparationand the Standard preparation,respectively.Calculate the quantity,in mg,of monensin Bin each g of the Monensin Granulated taken by the same formula,except that rUis the monensin Bpeak response obtained from the Assay preparationand rSis the monensin Apeak response obtained from the Standard preparation.Calculate the quantity,in mg,of monensin C/Din each g of the Monensin Granulated taken by the same formula,except that rUis the monensin C/Dpeak response obtained from the Assay preparation.Calculate the potency,in µg of monensin,in each mg of the Monensin Granulated taken by the formula:
A+0.28B+1.5C/D,
in which Ais the quantity,in mg,of monensin Ain each g of the Monensin Granulated taken,as calculated above,and Bis the quantity,in mg,of monensin Bin each g of the Monensin Granulated taken,and C/Dis the quantity,in mg,of monensin C/Din each g of Monensin Granulated taken,as calculated above.
Auxiliary Information— Staff Liaison:Ian DeVeau,Ph.D.,Senior Scientist
Expert Committee:(VET)Veterinary Drugs
USP28–NF23Page 1309
Phone Number:1-301-816-8178