Packaging and storage
Preserve in tight containers. Store at 25
, excursions permitted between 15
B: Thin-Layer Chromatographic Identification Test 201
5 mg per mL, in methanol.
Developing solvent system:
methanol and ammonium hydroxide (98.5:1.5).
Separately apply 1 µL of the Test solution and the Standard solution. Allow the applications to dry with the aid of a stream of nitrogen, develop in a saturated chromatographic chamber, and dry the plate in a current of air: the size, intensity, and RF value of the principal spot obtained from the Test solution correspond to those of the principal spot obtained from the Standard solution.
Examine the chromatogram obtained from the Assay preparation.
Calculate the percentage of impurities in the Xylazine Hydrochloride taken by the formula:
100rs / (rU + rs),
in which rs
is the sum of the areas of all the impurity peaks observed; and rU
is the area of the xylazine peak: the sum of the impurity responses is not greater than 2.0%.
Dissolve 6.0 g of sodium 1-heptanesulfonate in 2500 mL of water, add 60 mL of glacial acetic acid, dilute with water to 3000 mL, and mix. Prepare a mixture of 2200 mL of this solution and 1800 mL of methanol, and pass through a filter having a 0.5-µm or finer porosity. Make adjustments if necessary (see System Suitability
under Chromatography 621
Transfer about 25 mg of Xylazine Hydrochloride, accurately weighed, to a 25-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.
Chromatographic system (see Chromatography 621)
The liquid chromatograph is equipped with a 254-nm detector, a 2-mm × 2-cm guard column that contains packing L1, and a 3.9-mm × 30-cm analytical column that contains packing L1 and is maintained at a constant temperature of about 40
. The flow rate is about 2.5 mL per minute. Chromatograph the Standard preparation,
and record the peak responses as directed for Procedure:
the relative standard deviation for replicate injections is not more than 2.0%. [NOTE
After daily use, rinse the column with 100 mL of acetonitrile and with 100 mL of methanol, and store the column containing methanol.]
Separately inject equal volumes (about 20 µL) of the Standard preparation
and the Assay preparation
into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of C12
S.HCl in the portion of Xylazine Hydrochloride taken by the formula:
25C(rU / rS),
in which C
is the concentration, in mg per mL, of USP Xylazine Hydrochloride RS
in the Standard preparation;
are the areas of the xylazine peak responses in the chromatograms obtained from the Assay preparation
and the Standard preparation,