Identification—
To an accurately measured volume of Oral Suspension, equivalent to about 50 mg of demeclocycline hydrochloride, add 50 mL of methanol, shake, and allow the mixture to settle. Using the clear supernatant as the
Test Solution, proceed as directed for
Method II under
Identification—Tetracyclines 
193
.
Assay—
Mobile phase, Standard preparation, Resolution solution, and Chromatographic system—
Prepare as directed in the
Assay under
Demeclocycline.
Assay preparation—
Transfer an accurately weighed quantity of Oral Suspension, freshly mixed and free from air bubbles, equivalent to about 50 mg of demeclocycline hydrochloride (C21H21ClN2O8· HCl), to a 50-mL volumetric flask, dilute with 0.01 N hydrochloric acid to volume, and mix. Sonicate for 5 minutes, and centrifuge for 5 minutes. Pass a portion of the supernatant through a suitable filter having a 1.5-µm or finer porosity, and use the clear filtrate as the Assay preparation.
Procedure—
Proceed as directed for
Procedure in the
Assay under
Demeclocycline. Calculate the quantity, in mg, of demeclocycline hydrochloride (C
21H
21ClN
2O
8·HCl) equivalent in each mL of Oral Suspension taken by the formula:
0.05(CE / V)(rU / rS),
in which
V is the volume, in mL, of Oral Suspension taken; and the other terms are as defined therein.
