Packaging and storage—
Preserve in single-dose or in multiple-dose containers, preferably of Type I glass.
Identification, Infrared Absorption 
197K
—
Obtain the test specimen as follows. Filter a volume of Injectable Suspension, equivalent to about 100 mg of methylprednisolone acetate, through paper. Wash the residue with several 5-mL portions of water, and dry at 105
for 3 hours.
Particle size—
Transfer 1 drop to a microscope slide, and spread evenly, diluting with water, if necessary, to decrease the density of the field. Examine the slide under a microscope, equipped with a calibrated ocular micrometer, using about 400× magnification. Scan the entire slide, and note the size of the individual particles: not less than 99% of the particles are less than 20 µm in length when measured along the longest axis, and not less than 75% of the particles are less than 10 µm.
Other requirements—
It meets the requirements under
Injections 1.
Assay—
Mobile phase, Internal standard solution, Standard preparation, and Chromatographic system—
Proceed as directed in the
Assay under
Methylprednisolone Acetate.
Assay preparation—
Swirl the Injectable Suspension to ensure uniformity prior to analysis. Transfer an accurately measured volume of Injectable Suspension, equivalent to about 40 mg of methylprednisolone acetate, to a 25-mL volumetric flask, add 10.0 mL of Internal standard solution, dilute with chloroform to volume, and shake for about 15 minutes or until the aqueous layer is clear. Transfer 4.0 mL of the chloroform layer to a suitable vial, add 30 mL of chloroform and a small quantity (about 400 mg) of anhydrous sodium sulfate, shake for 5 minutes, and use the clear solution.
Procedure—
Proceed as directed for
Procedure in the
Assay under
Methylprednisolone Acetate. Calculate the quantity, in mg, of methylprednisolone acetate (C
24H
32O
6) in each mL of the Injectable Suspension taken by the formula:
(200C / V)(RU / RS),
in which
V is the volume, in mL, of Injectable Suspension taken, and the other terms are as defined therein.
