Identification, Infrared Absorption 
197K
—
Prepare the test specimen as follows. Grind to a fine powder a number of Tablets, equivalent to about 15 mg of glyburide, add 30 mL of acetonitrile, and shake. Filter the mixture, evaporate the filtrate to dryness, and dry the residue in vacuum at 60
for 3 hours.
Assay—
Mobile phase—
Prepare as directed in the
Assay for
Glyburide.
System suitability preparation—
Prepare a solution of progesterone in acetonitrile having a known concentration of about 0.2 mg per mL (
Solution A). Transfer about 10 mg of
USP Glyburide RS, accurately weighed, to a suitable container, add 20.0 mL of
Solution A, and shake vigorously to dissolve. Add 4.0 mL of water, and mix.
Standard preparation—
To about 10 mg of
USP Glyburide RS, accurately weighed, add 20.0 mL of acetonitrile, and shake vigorously to dissolve. Add 4.0 mL of water, and mix.
Assay preparation—
Transfer not fewer than 20 Tablets to a suitable container, add water equivalent to 0.4 mL of water per mg of glyburide, and swirl to disperse and wet Tablet material. Then add acetonitrile equivalent to 2.0 mL of acetonitrile per mg of glyburide, and shake for 30 minutes. Centrifuge a portion of the suspension so obtained, and use the clear supernatant.
Chromatographic system—
Proceed as directed in the
Assay for
Glyburide, except to use the
System suitability preparation in place of the
Standard preparation.
Procedure—
Separately inject equal volumes (about 10 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the height of the major peaks. Calculate the quantity, in mg, of glyburide (C
23 H
28ClN
3O
5S) in the portion of Tablets taken by the formula:
WS (rU / rS),
in which
WS is the weight, in mg, of
USP Glyburide RS taken to prepare the
Standard preparation; and
rU and
rS are the glyburide peak heights obtained from the
Assay preparation and the
Standard preparation, respectively.
