Procedure—
Proceed as directed for
Procedure in the
Assay under
Monensin. Calculate the quantity, in mg, of monensin A in each g of the Monensin Sodium taken by the formula:
(CFD / 100,000W)(rU / rS),
in which
C is the concentration, in µg per mL, of monensin activity in the
Standard preparation, based on the quantity of
USP Monensin Sodium RS taken, its designated potency, in µg per mg, and the extent of dilution;
F is the designated percentage of monensin A in
USP Monensin Sodium RS;
D is the dilution factor used in preparing the
Assay preparation; W is the quantity, in g, of Monensin Sodium taken to prepare the
Assay preparation; and
rU and
rS are the monensin A peak responses obtained from the
Assay preparation and the
Standard preparation, respectively. Calculate the quantity, in mg, of monensin B in each g of the Monensin Sodium taken by the same formula, except that
rU is the monensin B peak response obtained from the
Assay preparation, and
rS is the monensin A peak response obtained from the
Standard preparation. Calculate the quantity, in mg, of monensin C/D in each g of the Monensin Sodium taken by the same formula, except that
rU is the monensin C/D peak response obtained from the
Assay preparation. Calculate the potency, in mg of monensin, in each g of the Monensin Sodium taken by the formula:
A + 0.28B + 1.5C / D,
in which
A is the quantity, in mg, of monensin A in each g of the Monensin Sodium taken, as calculated above;
B is the quantity, in mg, of monensin B in each g of the Monensin Sodium taken; and
C/D is the quantity, in mg, of monensin C/D in each g of Monensin Sodium taken, as calculated above.
-methoxy-
,
,2,8-tetramethyl-1,6-dioxaspiro[4.5]decan-7–butanoic acid sodium salt
731
—
Dry it in vacuum at 60
for 3 hours: it loses not more than 4% of its weight.