, Standard preparation,
and Chromatographic system
Proceed as directed in the Assay
Transfer an accurately weighed portion of Ophthalmic Ointment, equivalent to about 12 mg of vidarabine, to a 100-mL volumetric flask, add 80 mL of water, and heat on a steam bath for 15 minutes. Shake, and add 10 mL of n-heptane to the hot suspension. Swirl, and cool to room temperature. Remove the n-heptane layer, and discard it. Dilute the aqueous phase with water to volume, and mix.
Proceed as directed for Procedure
in the Assay
Calculate the potency, in mg, of C10
per g of the Ophthalmic Ointment taken by the formula:
0.5F(rU / rS)(WS / WU),
in which WU
is the amount, in mg, of Ophthalmic Ointment taken; and the other terms are as defined therein.