Packaging and storage—
Store in well-closed containers in a cool, dry place, protected from light.
Labeling—
The label states the Latin binomial and, following the official name, the part of the plant source from which the article was derived.
Botanic characteristics—
Under a microscope, Powdered Garlic shows the following diagnostic characteristics: numerous fragments of parenchyma with large cells containing crystals of calcium oxalate and small triangular or quadrangular intercellular spaces at the corners; spiral vessels accompanied by subquadratic cells; elongated epidermal cells with thick, pitted walls.
Starch—
A water slurry of it shows no blue color when added to
iodine TS.
Loss on drying 
731
—
Dry 1 g of it at 105
for 2 hours: it loses not more than 7.0% of its weight.
Content of alliin—
0.045 M Phosphate buffer
,
0.05 M Phosphate buffer,
0.01 M Carboxymethoxylamine hemihydrochloride solution,
Derivatization reagent,
Mobile phase,
Standard solution, and
Chromatographic system—Proceed as directed in the test for
Content of alliin under Garlic.
Test solution—
Transfer about 1.0 g of Powdered Garlic, accurately weighed, to a flask, add 30.0 mL of 0.01 M Carboxymethoxylamine hemihydrochloride solution, and shake vigorously until the powder is fully dispersed. Centrifuge to obtain a clear solution. Transfer 5.0 mL of the supernatant to a 10-mL volumetric flask, dilute with 0.01 M Carboxymethoxylamine hemihydrochloride solution to volume, and mix. Using a syringe, transfer 0.1 mL of this solution to a septum-capped vial, add 0.5 mL of the Derivatization reagent, and mix. Allow a reaction time of not less than 2 minutes before injection into the chromatograph.
Procedure—
Proceed as directed in the test for
Content of alliin under Garlic. Calculate the percentage of alliin in the portion of Powdered Garlic taken by the formula:
6(C / W)(rU / rS),
in which
C is the concentration, in mg per mL, of
USP Alliin RS in the
Standard solution; W is the weight, in g, of Powdered Garlic taken for the
Test solution; and
rU and
rS are the sums of the peak responses for alliin diastereomers obtained from the
Test solution and the
Standard solution, respectively: not less than 0.3%, calculated on the dried basis, is found.
Content of 
-glutamyl-(S)-allyl-L-cysteine—
0.05 M Phosphate buffer
,
Mobile phase,
Standard solution, and
Chromatographic system—Proceed as directed in the test for
Content of -glutamyl-(
S)-
allyl-
L-
cysteine under
Garlic.
Test solution—
Transfer about 1.0 g of Powdered Garlic, accurately weighed, to a 50-mL volumetric flask, add 30 mL of methanol and water (1:1), and shake vigorously until the powder is fully dispersed. Dilute with a mixture of methanol and water (1:1) to volume, and mix. Centrifuge to obtain a clear solution.
Procedure—
Separately inject equal volumes (about 10 µL) of the
Standard solution and the
Test solution into the chromatograph, record the chromatograms, and measure the areas for the major peaks. Calculate the percentage of
-glutamyl-(
S)-allyl-
L-cysteine in the portion of Powdered Garlic taken by the formula:
5(C / W)(rU / rS),
in which
C is the concentration, in mg per mL, of USP
-Glutamyl-(
S)-Allyl-
L-Cysteine RS in the
Standard solution; W is the weight, in g, of Powdered Garlic taken to prepare the
Test solution; and
rU and
rS are the
-glutamyl-(
S)-allyl-
L-cysteine peak responses obtained from the
Test solution and the
Standard solution, respectively.
-Chlorogenin RS. USP