Identification—
The retention time of the major peak in the chromatogram of the
Assay preparation corresponds to that of the
Standard preparation obtained as directed in the
Assay.
Assay—
Standard preparation—
Dissolve an accurately weighed quantity of
USP Minocycline Hydrochloride RS in
Mobile phase to obtain a solution having a known concentration of about 500 µg of minocycline (C
23H
27N
3O
7) per mL. Use this solution within 1 hour.
Resolution solution—
Prepare a solution in water containing 2 mg of
USP Minocycline Hydrochloride RS per mL. Transfer 5 mL of this solution to a small beaker, and heat on a steam bath for 60 minutes. Evaporate to dryness, dissolve the residue in about 25 mL of
Mobile phase, and filter.
Assay preparation—
Transfer an accurately measured quantity of Oral Suspension, freshly mixed and free from air bubbles, equivalent to about 50 mg of C
23H
27N
3O
7, to a 100-mL volumetric flask, dilute with
Mobile phase to volume, mix, and filter. Use this solution within 1 hour.
Procedure—
Proceed as directed for
Procedure in the
Assay under
Minocycline Hydrochloride. Calculate the quantity, in mg, of C
23H
27N
3O
7 in each mL of the Oral Suspension taken by the formula:
0.1(C / V)(rU / rS),
in which
V is the volume, in mL, of Oral Suspension taken, and the other terms are as defined therein.
905
—