Pyrantel Pamoate
594.68Pyrimidine, 1,4,5,6-tetrahydro-1-methyl-2-[2-(2-thienyl)ethenyl]-, (E)-, compd. with 4,4¢-methylenebis[3-hydroxy-2-naphthalenecarboxylic acid] (1:1).
(E)-1,4,5,6-Tetrahydro-1-methyl-2-[2-(2-thienyl)vinyl]pyrimidine 4,4¢-methylenebis[3-hydroxy-2-naphthoate] (1:1)
[22204-24-6].» Pyrantel Pamoate contains not less than 97.0 percent and not more than 103.0 percent of C34H30N2O6S, calculated on the dried basis.
Packaging and storage—
Preserve in well-closed, light-resistant containers.
Identification—
C:
The chromatogram of the Assay preparation obtained as directed in the Assay exhibits major peaks due to pyrantel base and pamoic acid, the retention times of which correspond to those exhibited in the chromatogram of the Standard preparation obtained as directed in the Assay.
Loss on drying 
731
—
Dry it in vacuum at 60
for 3 hours: it loses not more than 2.0% of its weight.
731—
Dry it in vacuum at 60 for 3 hours: it loses not more than 2.0% of its weight.
Residue on ignition 281:
not more than 0.5%, from 1.33 g.
281:
not more than 0.5%, from 1.33 g.
Heavy metals, Method II 231:
0.005%.
231:
0.005%.
Limit of iron 241—
To the residue obtained in the test for Residue on ignition add 3 mL of hydrochloric acid and 2 mL of nitric acid, and evaporate on a steam bath to dryness. Dissolve the residue in 2 mL of hydrochloric acid with the aid of gentle heat. Add 18 mL of hydrochloric acid, dilute with water to 50 mL, and mix. Dilute 5 mL of this solution with water to 47 mL: the limit is 0.0075%.
241—
To the residue obtained in the test for Residue on ignition add 3 mL of hydrochloric acid and 2 mL of nitric acid, and evaporate on a steam bath to dryness. Dissolve the residue in 2 mL of hydrochloric acid with the aid of gentle heat. Add 18 mL of hydrochloric acid, dilute with water to 50 mL, and mix. Dilute 5 mL of this solution with water to 47 mL: the limit is 0.0075%.
Related compounds—
Test 1—
Chromatographic sheet—
Impregnate 18- × 56-cm filter paper (Whatman No. 1 or equivalent) with a freshly prepared 7:3 mixture of acetone and glycine–sodium chloride–hydrochloric acid buffer solution (prepared by mixing 3 volumes of a solution that is 0.3 M with respect to both glycine and sodium chloride with 7 volumes of 0.3 M hydrochloric acid). Press the impregnated paper uniformly between white, nonfluorescent blotters to remove the excess solvent.
Test solutions:
0.2 and 20 mg per mL, in a mixture of chloroform, methanol, and ammonium hydroxide (10:10:1).
Standard solutions:
0.2 and 20 mg per mL, in a mixture of chloroform, methanol, and ammonium hydroxide (10:10:1).
Application volume:
20 µL.
Developing solvent system:
a mixture of ethyl acetate, butyl alcohol, and water (10:1:1).
Procedure—
Proceed as directed for Descending Chromatography under Chromatography 621. Develop for 16 to 20 hours. Remove the sheet from the chamber, air-dry for 10 minutes, transfer to an air-circulating oven, and dry at 60 for 30 minutes. Examine the chromatogram on a 254-nm UV scanner screen: the RF value of the principal spot from the Test solution corresponds to that obtained from the appropriate Standard solution; and no spot in the chromatogram of the more concentrated Test solution, other than the principal spot, is larger or more intense than the principal spot from the less concentrated Test solution.
621. Develop for 16 to 20 hours. Remove the sheet from the chamber, air-dry for 10 minutes, transfer to an air-circulating oven, and dry at 60 for 30 minutes. Examine the chromatogram on a 254-nm UV scanner screen: the RF value of the principal spot from the Test solution corresponds to that obtained from the appropriate Standard solution; and no spot in the chromatogram of the more concentrated Test solution, other than the principal spot, is larger or more intense than the principal spot from the less concentrated Test solution.
Test 2—
Adsorbent:
0.25-mm layer of chromatographic silica gel mixture.
Test stock solution—
Transfer about 100 mg of Pyrantel Pamoate, accurately weighed, to a 10-mL volumetric flask, dissolve in and dilute with dimethylformamide to volume, and mix.
Test solution—
Transfer 1.0 mL of the Test stock solution to a 100-mL volumetric flask, dilute with dimethylformamide to volume, and mix.
Standard solution—
Transfer about 50 mg of USP Pyrantel Pamoate RS to a 5-mL volumetric flask, dilute with dimethylformamide to volume, and mix.
Developing solvent system:
a mixture of ethyl acetate, water, and glacial acetic acid (3:1:1).
Procedure—
Proceed as directed for Thin-Layer Chromatography under Chromatography 621, except to line the developing chamber with filter paper, and allow to equilibrate. Apply 5-µL portions of the Test stock solution, the Test solution, and the Standard solution to the plate, and allow to dry. Develop the chromatogram until the solvent front has moved about 10 cm. Remove the plate from the developing chamber, and allow to air-dry for about 10 minutes. Examine the plate under short-wavelength UV light. The chromatograms obtained from the Test stock solution and the Test solution exhibit spots for pyrantel and the pamoate moiety at relative positions corresponding to those obtained from the chromatogram of the Standard solution: the RF value of pyrantel is about 0.3, and the RF value of the pamoate moiety is about 0.8. No spot obtained from the Test stock solution, other than that of pyrantel and the pamoate moiety, is more intense than the pyrantel spot obtained from the Test solution.
621, except to line the developing chamber with filter paper, and allow to equilibrate. Apply 5-µL portions of the Test stock solution, the Test solution, and the Standard solution to the plate, and allow to dry. Develop the chromatogram until the solvent front has moved about 10 cm. Remove the plate from the developing chamber, and allow to air-dry for about 10 minutes. Examine the plate under short-wavelength UV light. The chromatograms obtained from the Test stock solution and the Test solution exhibit spots for pyrantel and the pamoate moiety at relative positions corresponding to those obtained from the chromatogram of the Standard solution: the RF value of pyrantel is about 0.3, and the RF value of the pamoate moiety is about 0.8. No spot obtained from the Test stock solution, other than that of pyrantel and the pamoate moiety, is more intense than the pyrantel spot obtained from the Test solution.
Content of pamoic acid—
Mobile phase and Chromatographic system—
Prepare as directed in the Assay.
Standard solution—
Dissolve an accurately weighed quantity of USP Pamoic Acid RS in Mobile phase to obtain a solution having a known concentration of about 0.52 mg per mL. Transfer 1.0 mL of this solution to a 10-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Test solution—
Use the Assay preparation.
Procedure—
Inject equal volumes (about 20 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and record the peak responses as directed in the Assay. Calculate the quantity, in mg, of C23H16O6 in the portion of Pyrantel Pamoate taken by the formula:
1000C(rU / rS)
in which C is the concentration, in mg per mL, of USP Pamoic Acid RS in the Standard solution and rU and rS are the peak responses for pamoic acid obtained from the Test solution and the Standard solution, respectively: the content of pamoic acid is between 63.4% and 67.3%, calculated on the dried basis.
Assay—
[note—Use low-actinic glassware in preparing solutions of pyrantel pamoate, and otherwise protect the solutions from unnecessary exposure to bright light. Complete the Assay without prolonged interruption.]
Mobile phase—
Prepare a mixture of acetonitrile, acetic acid, water, and diethylamine (92.8:3:3:1.2), filter, and degas. Make adjustments if necessary (see System Suitability under Chromatography 621). [note—Increasing the amount of acetonitrile in Mobile phase increases retention times. Increasing the amount of acetic acid, water, and diethylamine decreases retention times. Should the Mobile phase need to be adjusted, maintain the ratios among acetic acid, water, and diethylamine (1:1:0.4).]
621). [note—Increasing the amount of acetonitrile in Mobile phase increases retention times. Increasing the amount of acetic acid, water, and diethylamine decreases retention times. Should the Mobile phase need to be adjusted, maintain the ratios among acetic acid, water, and diethylamine (1:1:0.4).]
Standard preparation—
Prepare a solution in Mobile phase having an accurately known concentration of about 80 µg of USP Pyrantel Pamoate RS per mL.
Assay preparation—
Transfer about 80 mg of Pyrantel Pamoate, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix. Dilute 1.0 mL of this solution with Mobile phase to 10.0 mL, and mix.
Chromatographic system (see Chromatography 621)—
The liquid chromatograph is equipped with a 288-nm detector and 4.6-mm × 25-cm column that contains packing L3. The flow rate is about 1.0 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the resolution, R, between pyrantel and pamoic acid is not less than 10.0; the number of theoretical plates for the pyrantel peak is not less than 8000; the tailing factor for the pyrantel peak is not greater than 1.3; and the relative standard deviation for replicate injections is not more than 1.0%.
621)—
The liquid chromatograph is equipped with a 288-nm detector and 4.6-mm × 25-cm column that contains packing L3. The flow rate is about 1.0 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the resolution, R, between pyrantel and pamoic acid is not less than 10.0; the number of theoretical plates for the pyrantel peak is not less than 8000; the tailing factor for the pyrantel peak is not greater than 1.3; and the relative standard deviation for replicate injections is not more than 1.0%.
Procedure—
Separately inject equal volumes (about 20 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms obtained for a period of not less than 2.5 times the retention times of pyrantel, and measure the responses for the major peaks. The relative retention times for pamoic acid and pyrantel are about 0.6 and 1.0, respectively. Calculate the quantity, in mg, of C34H30N2O6S in the portion of Pyrantel Pamoate taken by the formula:
1000C(rU / rS)
in which C is the concentration, in mg, of USP Pyrantel Pamoate RS in the Standard preparation, and rU and rS are the peak responses for pyrantel obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
Chromatographic Column—
| Topic/Question | Contact | Expert Committee |
| Monograph | Behnam Davani, Ph.D., M.B.A.
Senior Scientist 1-301-816-8394 |
(MDAA05) Monograph Development-Antivirals and Antimicrobials |
| Reference Standards | Lili Wang, Technical Services Scientist 1-301-816-8129 RSTech@usp.org |
USP32–NF27 Page 3446
Pharmacopeial Forum: Volume No. 34(6) Page 1482
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.