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Ramipril
(ra' mi pril).
» Ramipril contains not less than 98.0 percent and not more than 102.0 percent of C23H32N2O5, calculated on the dried basis.
Packaging and storage
Preserve in tight containers.
USP Reference standards
USP Ramipril Related Compound A RS
(2S,3aS,6aS)-1-[(S)2-[[(S)1-(Methoxycarbonyl)-3-phenylpropyl]amino]-1-oxopropyl]-octahydrocyclopenta[b]pyrrole-2-carboxylic acid. C22H30N2O5 402.48
USP Ramipril Related Compound B RS
(2S,3aS,6aS)-1-[(S)2-[[(S)1-(Methylethoxy)carbonyl-3-phenylpropyl]amino]-1-oxopropyl]-octahydrocyclopenta[b]pyrrole-2-carboxylic acid. C24H34N2O5 430.54
Identification,
Infrared Absorption
Melting range
Specific rotation
Test solution:
10 mg per mL, in 0.1 M methanolic hydrochloric acid.
Loss on drying
Residue on ignition
Limit of palladium
Diluent
Prepare a mixture of water and nitric acid (997:3).
Standard stock solution
Transfer about 50 mg of palladium metal, accurately weighed, to a 100-mL volumetric flask, dissolve in 9 mL of hydrochloric acid, and dilute with water to volume.
Standard solutions
Dilute the Standard stock solution quantitatively, and stepwise if necessary, with Diluent to obtain solutions containing 0.02, 0.03, and 0.05 µg of palladium per mL.
Test solution
Transfer about 200 mg of Ramipril, accurately weighed, to a 100-mL volumetric flask, and dissolve in and dilute with Diluent to volume.
Blank solution
Transfer about 150 mg of magnesium nitrate to a 100-mL volumetric flask, and dissolve in and dilute with Diluent to volume.
Procedure
Concomitantly determine the absorbances of equal volumes of the Standard solutions and the Test solution (about 20 µL), at the palladium emission line at 247.6 nm, with a suitable atomic absorption spectrophotometer (see Spectrophotometry and Light-Scattering
0.1CP / CR,
in which CR is the concentration, in mg per mL, of Ramipril taken to prepare the Test solution. The limit is 0.002%.
Related compounds
Solution A
Dissolve 2.0 g of sodium perchlorate in a mixture of 800 mL of water and 0.5 mL of triethylamine, adjust with phosphoric acid to a pH of about 3.6 ± 0.1, add 200 mL of acetonitrile, and mix.
Solution B
Dissolve 2.0 g of sodium perchlorate in a mixture of 300 mL of water and 0.5 mL of triethylamine, adjust with phosphoric acid to a pH of about 2.6 ± 0.1, add 700 mL of acetonitrile, and mix.
Mobile phase
Use variable filtered and degassed mixtures of Solution A and Solution B as directed for Chromatographic system. Make adjustments if necessary (see System Suitability under Chromatography
Test solution
Transfer about 25 mg of Ramipril, accurately weighed, to a 25-mL volumetric flask, dissolve in and dilute with Solution A to volume, and mix. [noteKeep the Test solution cold until injected. ]
Resolution solution
Dissolve a quantity of USP Ramipril RS, USP Ramipril Related Compound A RS, USP Ramipril Related Compound B RS, USP Ramipril Related Compound C RS, and USP Ramipril Related Compound D RS in Solution B to obtain a solution with a concentration of about 0.5 mg of each per mL.
Standard solution
Dissolve an accurately weighed quantity of USP Ramipril RS in Solution B, and dilute quantitatively, and stepwise if necessary, with Solution B to obtain a solution having a known concentration of about 0.005 mg per mL.
Chromatographic system (see Chromatography
[noteMake adjustments at the 75:25 ratio stage, if necessary, to achieve elution of ramipril between 16 and 19 minutes after injection of the Standard solution. ]
Chromatograph the Resolution solution, and record the peak responses as directed for Procedure: the resolution, R, between ramipril related compound A and ramipril is not less than 3.0. Similarly chromatograph the Test solution, and record the peak responses as directed for Procedure: the retention time for ramipril is between 16 and 19 minutes; and the tailing factor for the ramipril peak is between 0.8 and 2.0. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the relative standard deviation for replicate injections is not more than 5.0%. [noteThe relative retention times are about 0.8 for ramipril related compound A, 1.0 for ramipril, 1.3 for ramipril related compound B, 1.5 for ramipril related compound C, and 1.6 for ramipril related compound D. ]
Procedure
Separately inject equal volumes (about 10 µL) of the Test solution and the Standard solution into the chromatograph, record the chromatograms, and measure the peak response for ramipril obtained from the Standard solution and the responses of all the peaks, other than the ramipril peak, obtained from the Test solution. Calculate the percentage of each related compound and unknown impurity in the portion of Ramipril taken by the formula:
100F(CS / CT)(ri / rS)
in which F is the relative response factor for the related compound, which is 2.4 for ramipril related compound C, and 1.0 for all other individual impurities; CS is the concentration, in mg per mL, of USP Ramipril RS in the Standard solution; CT is the concentration, in mg per mL, of ramipril in the Test solution; ri is the peak response for each individual peak obtained from the Test solution; and rS is the ramipril peak response obtained from the Standard solution: not more than 0.5% of ramipril related compound A, ramipril related compound B, ramipril related compound C, or ramipril related compound D is found; not more than 0.1% of any other individual impurity is found; and not more than 1.0% of total impurities is found.
Assay
Sodium dodecyl sulfate solution
Prepare a 0.1% solution of sodium dodecyl sulfate. Adjust with phosphoric acid to a pH of 2.4 ± 0.1, filter, and degas.
Mobile phase
Prepare a mixture of Sodium dodecyl sulfate solution and acetonitrile (55:45). Adjust with phosphoric acid to a pH of 2.75 ± 0.1, filter, and degas. Make adjustments if necessary (see System Suitability under Chromatography
System suitability preparation
Dissolve accurately weighed quantities of USP Ramipril RS and USP Ramipril Related Compound A RS in Mobile phase to obtain a solution having known concentrations of about 0.2 mg per mL and 0.01 mg per mL, respectively.
Standard preparation
Dissolve an accurately weighed quantity of USP Ramipril RS in Mobile phase to obtain a solution having a known concentration of about 0.2 mg per mL.
Assay preparation
Transfer about 100 mg of Ramipril, accurately weighed, to a 100-mL volumetric flask, dissolve in about 10 mL of acetonitrile, dilute with Mobile phase to volume, and mix. Pipet about 10 mL of this stock solution to a 50-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Chromatographic system (see Chromatography
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 all of the peaks. Calculate the quantity, in mg, of C23H32N2O5 in the portion of Ramipril taken by the formula:
500C(rU / rS)
in which C is the concentration, in mg per mL, of USP Ramipril 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 4517
Pharmacopeial Forum: Volume No. 31(3) Page 787
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