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Clonidine Hydrochloride Tablets
» Clonidine Hydrochloride Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C9H9Cl2N3·HCl.
Packaging and storage
Preserve in well-closed containers.
Identification
A:
The retention time exhibited by clonidine hydrochloride in the chromatogram of the Assay preparation corresponds to that of clonidine hydrochloride in the chromatogram of the Standard preparation as obtained in the Assay.
B:
Transfer a quantity of finely powdered Tablets, equivalent to about 1 mg of clonidine hydrochloride, to a separator containing 30 mL of water and 5 mL of 1 N sodium hydroxide. Swirl gently to dissolve the test specimen, and extract with 20 mL of chloroform. Allow the layers to separate, and filter the chloroform extract. Evaporate the filtrate to dryness, and dissolve the residue in 0.1 mL of methanol to obtain the test solution. Prepare a Standard solution in methanol containing 10 mg of USP Clonidine Hydrochloride RS per mL. Apply separately 2-µL portions of the test solution and the Standard solution to a suitable thin-layer chromatographic plate (see Chromatography
Dissolution
Medium:
0.01 N hydrochloric acid; 500 mL.
Apparatus 2:
50 rpm.
Time:
30 minutes.
Procedure
Using Dissolution Medium instead of Mobile phase to prepare the Standard clonidine hydrochloride stock solution and the Standard preparation, determine the amount of C9H9Cl2N3·HCl dissolved, employing the procedure set forth in the Assay, making any necessary modifications.
Tolerances
Not less than 75% (Q) of the labeled amount of C9H9Cl2N3·HCl is dissolved in 30 minutes.
Uniformity of dosage units
Assay
Mobile phase
Dissolve 1.1 g of sodium 1-octanesulfonate in 500 mL of water, and add 500 mL of methanol and 1 mL of phosphoric acid. Mix, and adjust with 1 N sodium hydroxide to a pH of 3.0. Mix, filter through a 0.45-µm or finer porosity filter, and degas. Make adjustments if necessary (see System Suitability under Chromatography
Standard clonidine hydrochloride stock solution
Dissolve an accurately weighed quantity of USP Clonidine Hydrochloride RS in Mobile phase, and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 100 µg per mL.
2
,6-Dichloroaniline stock solutionTransfer about 12 mg of 2,6-dichloroaniline to a 100-mL volumetric flask, add Mobile phase to volume, and mix. Dilute an accurately measured volume of this solution quantitatively with Mobile phase to obtain 2,6-Dichloroaniline stock solution having a known concentration of about 12 µg per mL.
Standard preparation
Transfer 2.0 mL of Standard clonidine hydrochloride stock solution to a 200-mL volumetric flask, dilute with Mobile phase to volume, and mix. This solution contains about 1 µg of clonidine hydrochloride.
Assay preparation
Weigh and finely powder not less than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 0.1 mg of clonidine hydrochloride, to a 100-mL volumetric flask. Add about 60 mL of Mobile phase, shake by mechanical means for 15 to 30 minutes, dilute with Mobile phase to volume, and mix. Centrifuge a portion of this solution to obtain a clear solution (Assay preparation).
System suitability preparation
Transfer 2.0 mL of Standard clonidine hydrochloride stock solution and 20.0 mL of 2,6-Dichloroaniline stock solution to a 100-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Chromatographic system
(see Chromatography
Procedure
[noteUse peak areas where peak responses are indicated. ] Separately inject equal volumes (about 50 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 C9H9Cl2N3·HCl in the portion of Tablets taken by the formula:
0.1C(rU / rS)
in which C is the concentration, in µg per mL, of USP Clonidine Hydrochloride RS in the Standard preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 2729
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