Ivermectin Topical Solution
» Ivermectin Topical Solution is a topical solution in a suitable vehicle. It contains not less than 95.0 percent and not more than 105.0 percent of the labeled amount of Ivermectin, calculated as the sum of component H2B1a (C48H74O14) plus component H2B1b (C47H72O14). The ratio of the contents, H2B1a / (H2B1a + H2B1b), is not less than 90.0 percent.
Packaging and storage
Preserve in well-closed containers. Store at a temperature not more than 30.
Labeling
Label it to indicate that it is for veterinary use only.
Identification
A:
Thin-Layer Chromatographic Identification Test 201
Test solution
Dissolve a volume of Topical Solution in methanol, and dilute quantitatively, and stepwise if necessary, with methanol to obtain a solution containing 0.5 mg per mL of ivermectin, and filter.
Injection volume:
2 µL.
Developing solvent system:
unsaturated chamber, freshly prepared and equilibrated mixture of methylene chloride, methanol, and ammonium hydroxide (90:9:1).
Procedure
Remove the plate, allow to air dry, and examine under short- and long-wavelength UV light: the retardation factor, RF , of the principal spot obtained from the Test solution corresponds to that obtained from the Standard solution.
B:
The retention times of the two principal component peaks of ivermectin in the chromatogram of the Assay preparation corresponds to that of the two principal component peaks of ivermectin in the chromatogram of the Standard preparation, obtained as directed in the Assay.
Chromatographic purity
Mobile phase and Chromatographic system
Proceed as directed in the Assay.
Standard solutionDissolve an accurately weighed quantity of USP Ivermectin RS in methanol, and dilute quantitatively, and stepwise if necessary, with methanol to obtain a 0.004 mg per mL solution.
Test solution
Dissolve a quantity of Topical Solution in methanol, and dilute quantitatively, and stepwise if necessary, with methanol to obtain a solution containing 0.4 mg of ivermectin per mL of solution, based on the label claim.
Procedure
Inject equal volumes (about 20 µL) of the Test solution and the Standard solution into the chromatograph, record the chromatograms, and measure all of the peak responses. Calculate the percentage of each impurity in the portion of Topical Solution taken by the formula:
100(CS / CT) (ri / rS)
in which CS is the concentration, in mg per mL, of ivermectin in the Standard solution; CT is the concentration, in mg per mL, of ivermectin in the Test solution; ri is the peak response for each impurity from the Test solution; and rS is the ivermectin peak response obtained from Standard solution. Not more than 2.7% of the peak with a relative retention time of about 1.3 to 1.5 to that of the principal peak is found; not more than 1.0% of any other impurity is found; and not more than 6.0% of total impurities is found. Disregard any peak below 0.05%.
Assay
Mobile phase
Prepare a filtered and degassed mixture of acetonitrile, methanol, and water (106:55:39). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation
Dissolve an accurately weighed quantity of USP Ivermectin RS in methanol, and dilute quantitatively, and stepwise if necessary, with methanol to obtain a solution having a known concentration of about 0.4 mg per mL.
Assay preparation
Dilute a volume of Topical Solution, quantitatively, and stepwise if necessary, with methanol to obtain a solution containing 0.4 mg of ivermectin per mL of solution, based on the label claim.
Chromatographic system (see Chromatography 621)
The liquid chromatograph is equipped with a 245-nm detector and a 4.6-mm × 25-cm column that contains packing L1. The flow rate is about 1.5 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the resolution, R, between the first peak (component H2B1b) and the second peak (component H2B1a) is not less than 3.0; and the relative standard deviation for replicate injections is not more than 2.0%, determined from the H2B1a peak.
Procedure
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 component H2B1a plus component H2B1b. Calculate the percentage of label claim of ivermectin (H2B1a + H2B1b) in the portion of Topical Solution taken by the formula:
100(CS / CU) (rU / rS)
in which CS is the concentration, in mg per mL, of USP Ivermectin RS in the Standard preparation; CU is the concentration, in mg per mL, of ivermectin in the Assay preparation; rU is the total peak response of H2B1a plus H2B1b peaks obtained from the Assay preparation; and rS is the total peak response of H2B1a plus H2B1b peaks obtained from the Standard preparation. Calculate the ratio of the contents, in percent, of H2B1a / (H2B1a + H2B1b) in the portion of Topical Solution taken by the formula:
100(r1 / rU)
in which r1 is the peak response of H2B1a obtained from the Assay preparation; and rU is as described above.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
Chromatographic Column
USP32NF27 Page 2732
Pharmacopeial Forum: Volume No. 33(5) Page 916
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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