Identification
The chromatogram of the
Assay preparation obtained as directed in the
Assay exhibits a major peak for tetracycline, the retention time of which corresponds to that exhibited in the chromatogram of the
Standard preparation obtained as directed in the
Assay.
Assay
Diluting solvent, Mobile phase, Standard preparation, Resolution solution, and Chromatographic system
Prepare as directed in the
Assay under
Tetracycline Hydrochloride.
Assay preparation
Transfer an accurately measured volume of Ophthalmic Suspension, equivalent to about 50 mg of tetracycline hydrochloride, with the aid of 30 mL of cyclohexane to a 125-mL separator, add 30 mL of Diluting solvent, insert the stopper, and shake. Allow to separate, and collect the lower layer in a 100-mL volumetric flask. Repeat the extraction with two additional 30-mL portions of Diluting solvent, combining the extracts in the 100-mL volumetric flask. Add Diluting solvent to volume, mix, and filter.
Procedure
Proceed as directed for
Procedure in the
Assay under
Tetracycline Hydrochloride. Calculate the quantity, in mg per mL, of C
22H
24N
2O
8·HCl equivalent in the Ophthalmic Suspension taken by the formula:
(CP / 10V)(rU / rS),
in which
V is the volume, in mL, of Ophthalmic Suspension taken, and the other terms are as defined therein.