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Nifedipine Extended-Release Tablets
» Nifedipine Extended-Release Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of nifedipine (C17H18N2O6).
Packaging and storage— Preserve in tight, light-resistant containers, and store at controlled room temperature.
Labeling— The labeling indicates the Drug Release Test with which the product complies.
Labeling— The labeling indicates the Dissolution Test with which the product complies.
(Official April 1, 2006)
USP Reference standards 11— USP Nifedipine RS. USP Nifedipine Nitrophenylpyridine Analog RS. USP Nifedipine Nitrosophenylpyridine Analog RS.
NOTE—Nifedipine, when exposed to daylight and certain wavelengths of artificial light, readily converts to a nitrosophenylpyridine derivative. Exposure to UV light leads to the formation of a nitrophenylpyridine derivative. Perform assays and tests in the dark or under golden fluorescent or other low-actinic light. Use low-actinic glassware.
Identification—
A: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
B: Ultraviolet Absorption 197U—
Solutions— Prepare a test solution as directed for the Assay preparation in the Assay, except to dilute further with Mobile phase to obtain a solution having a concentration of about 0.02 mg per mL. Prepare the Standard solution as directed for the Standard preparation in the Assay under Nifedipine, except to dilute further with Mobile phase to obtain a solution having a known concentration of about 0.02 mg per mL.
Drug release 724—
Test 1— If the product complies with this test, the labeling indicates that it meets USP Drug Release Test 1.
Medium: water; 50 mL.
Apparatus 7: 15 to 30 cycles per minute. Do not use the reciprocating disk, but use a 25-cm plexiglas rod, the perimeter of the Tablets being affixed to the rod with a water-insoluble glue. The solution containers are 25-mm test tubes, 150 to 200 mm in length, and the water bath is maintained at 37 ± 0.5. At the end of each specified test interval, the systems are transferred to the next row of new test tubes containing 50 mL of fresh Medium.
Times: 4, 8, 12, 16, 20, and 24 hours.
Diluting solution: a mixture of methanol and water (1:1).
Standard solutions— Transfer about 50 mg of USP Nifedipine RS, accurately weighed, to a 100-mL volumetric flask, dissolve in 50 mL of methanol, dilute with water to volume, and mix to obtain a Standard stock solution. Quantitatively dilute this Standard stock solution with Diluting solution to obtain solutions having suitable known concentrations.
Test solution— Use portions of the solution under test, passed through a 0.4-µm filter, suitably diluted with methanol, and stepwise, if necessary, with Diluting solution to obtain a final mixture consisting of equal parts of methanol and water.
Procedure— Determine the amount of C17H18N2O6 released in the Test solution at each 4-hour interval by employing UV absorption at the wavelength of maximum absorbance at about 338 nm, in 0.5-cm cells. [NOTE—For the 4-hour time period, determine the absorbance at 456 nm, and use this determination to correct for excipient interference.]
Tolerances— The cumulative percentages of the labeled amount of nifedipine (C17H18N2O6), released in vivo and dissolved at the times specified, conform to Acceptance Table 1.
Time (hours) Amount dissolved*
4 between 5% and 17%
8 —
12 between 43% and 80%
16 —
20 —
24 not less than 80%
*  The amount dissolved is expressed in terms of the labeled tablet strength rather than in terms of the labeled total contents.
Test 2— If the product complies with this test, the labeling indicates that it meets USP Drug Release Test 2.
Buffer concentrate— Transfer 330.9 g of dibasic sodium phosphate and 38 g of citric acid to a 1-L volumetric flask, add water to dissolve, add 10 mL of phosphoric acid, dilute with water to volume, and mix.
Medium— Mix 125.0 mL of Buffer concentrate and 1 L of 10% sodium lauryl sulfate solution, and dilute to 10 L. Adjust if necessary to a pH of 6.8; 900 mL.
Apparatus 2: 50 rpm, with sinkers (see Figure 1).
Click to View Image
Fig. 1 (printed with permission of the Japanese Pharmacopoeia)
Times: 3, 6, and 12 hours.
Determine the amount of nifedipine (C17H18N2O6) dissolved by employing the following method.
Mobile phase— Prepare a filtered and degassed mixture of acetonitrile and water (70:30). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard solution— Dissolve an accurately weighed quantity of USP Nifedipine RS in methanol to obtain a solution having a known concentration of about 1.11 mg per mL. Dilute quantitatively and stepwise with Medium to obtain a solution having a known concentration of 0.1 mg per mL.
Chromatographic system— The liquid chromatograph is equipped with a 350-nm detector and a 4.0-mm × 125-mm column that contains 3-µm packing L1. The flow rate is about 1.5 mL per minute. The column temperature is maintained at about 40. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the column efficiency is not less than 2000 theoretical plates; the tailing factor is not more than 1.5; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Separately inject equal volumes (about 20 µL) of filtered portions of the Standard solution and the solution under test into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Determine the amount of nifedipine (C17H18N2O6) dissolved.
Tolerances— The percentages of the labeled amount of nifedipine (C17H18N2O6) released in vivo and dissolved at the times specified conform to Acceptance Table 1.
Time (hours) Amount dissolved
3 between 10% and 30%
6 between 40% and 65%
12 not less than 80%
Test 3— If the product complies with this test, the labeling indicates that it meets USP Drug Release Test 3.
FOR TABLETS LABELED TO CONTAIN 30 MG OF NIFEDIPINE—
Phase 1:
Medium: 0.05 M phosphate buffer, pH 7.5; 900 mL.
Apparatus 2: 100 rpm.
Time: 1 hour.
Standard solution— Prepare a solution in Medium having an accurately known concentration of about 0.034 mg of USP Nifedipine RS per mL. If necessary, a volume of methanol, not exceeding 10% of the final volume, can be used to help solubilize nifedipine.
Procedure— [NOTE—After the run, take the Tablet out of the dissolution vessel, adapt a sinker to it, and transfer the Tablet with the sinker to the dissolution vessel containing the Medium for Phase 2.] Determine the amount of C17H18N2O6 released in Phase 1 from UV absorbances at the wavelength of maximum absorbance at about 238 nm using filtered portions of the solution under test, in comparison with the Standard solution, using the Medium as the blank.
Phase 2:
Medium: 0.5% sodium lauryl sulfate in simulated gastric fluid without enzyme, pH 1.2; 900 mL.
Apparatus 2: 100 rpm.
Times: 1, 4, 8, and 12 hours.
Standard solution— Prepare a solution in Medium having an accurately known concentration of about 0.034 mg of USP Nifedipine RS per mL. If necessary, a volume of methanol, not exceeding 10% of the final volume, can be used to help solubilize nifedipine.
Procedure— Determine the amount of C17H18N2O6 released in Phase 2 from UV absorbances at the wavelength of maximum absorbance at about 238 nm using filtered portions of the solution under test, in comparison with the Standard solution, using Medium as the blank.
Tolerances— The cumulative percentages of the labeled amount of nifedipine (C17H18N2O6), released in vivo and dissolved at the times specified, conform to Acceptance Table 1.
Time (hours) Amount dissolved*
1 not more than 30%
4 between 30% and 55%
8 not less than 60%
12 not less than 80%
*  For each dosage unit, add the amount dissolved in phosphate buffer, pH 7.5 from Phase 1 to the amount dissolved at each time point in Phase 2.
FOR TABLETS LABELED TO CONTAIN 60 MG OF NIFEDIPINE—
Phase 1:
Medium: 0.05 M phosphate buffer, pH 7.5; 900 mL.
Apparatus 2: 100 rpm.
Time: 25 minutes.
Standard solution— Prepare a solution in Medium having an accurately known concentration of about 0.067 mg of USP Nifedipine RS per mL. If necessary, a volume of methanol, not exceeding 10% of the final volume, can be used to help solubilize nifedipine.
Procedure— [NOTE—After the run, take the Tablet out of the dissolution vessel, adapt a sinker to it, and transfer the Tablet with the sinker to the dissolution vessel containing the Medium for Phase 2.] Determine the amount of C17H18N2O6 released in Phase 1 from UV absorbances at the wavelength of maximum absorbance at about 238 nm using filtered portions of the solution under test, in comparison with the Standard solution, using the Medium as the blank.
Phase 2:
Medium: 0.5% sodium lauryl sulfate in simulated gastric fluid without enzyme, pH 1.2; 900 mL.
Apparatus 2: 100 rpm.
Times: 1, 4, 8, and 12 hours.
Standard solution— Prepare a solution in Medium having an accurately known concentration of about 0.067 mg of USP Nifedipine RS per mL. If necessary, a volume of methanol, not exceeding 10% of the final volume, can be used to help solubilize nifedipine.
Procedure— Determine the amount of C17H18N2O6 released in Phase 2 from UV absorbances at the wavelength of maximum absorbance at about 238 nm using filtered portions of the solution under test, in comparison with the Standard solution, using Medium as the blank.
Tolerances— The cumulative percentages of the labeled amount of nifedipine (C17H18N2O6), released in vivo and dissolved at the times specified, conform to Acceptance Table 1.
Time (hours) Amount dissolved*
1 not more than 30%
4 between 40% and 70%
8 not less than 70%
12 not less than 80%
*  For each dosage unit, add the amount dissolved in phosphate buffer, pH 7.5 from Phase 1 to the amount dissolved at each time point in Phase 2.
Test 4— If the product complies with this test, the labeling indicates that the product meets USP Drug Release Test 4.
Medium: 0.5% sodium lauryl sulfate in simulated gastric fluid without enzyme, pH 1.2; 900 mL.
Apparatus 2: 100 rpm.
Times: 1, 4, and 12 hours.
Standard solution— Prepare a solution in Medium having an accurately known concentration of about 0.067 mg of USP Nifedipine RS per mL for Tablets labeled to contain 60 mg, and of about 0.034 mg of USP Nifedipine RS per mL for Tablets labeled to contain 30 mg. If necessary, a volume of methanol, not exceeding 10% of the final volume, can be used to help solubilize nifedipine.
Procedure— Determine the amount of C17H18N2O6 released from UV absorbances at the wavelength of maximum absorbance at about 238 nm using filtered portions of the solution under test, in comparison with the Standard solution, using the Medium as the blank.
Tolerances— The cumulative percentages of the labeled amount of nifedipine (C17H18N2O6), released at the times specified, conform to Acceptance Table 1.
FOR TABLETS LABELED TO CONTAIN 30 MG OF NIFEDIPINE
Time (hours) Amount dissolved
1 between 12% and 35%
4 between 44% and 67%
12 not less than 80%
FOR TABLETS LABELED TO CONTAIN 60 MG OF NIFEDIPINE
Time (hours) Amount dissolved
1 between 10% and 30%
4 between 40% and 63%
12 not less than 80%
Dissolution 711—
Test 1— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 1.
Medium: water; 50 mL.
Apparatus 7 (see Drug Release 724): 15 to 30 cycles per minute. Do not use the reciprocating disk, but use a 25-cm plexiglas rod, the perimeter of the Tablets being affixed to the rod with a water-insoluble glue. The solution containers are 25-mm test tubes, 150 to 200 mm in length, and the water bath is maintained at 37 ± 0.5. At the end of each specified test interval, the systems are transferred to the next row of new test tubes containing 50 mL of fresh Medium.
Times: 4, 8, 12, 16, 20, and 24 hours.
Diluting solution: a mixture of methanol and water (1:1).
Standard solutions— Transfer about 50 mg of USP Nifedipine RS, accurately weighed, to a 100-mL volumetric flask, dissolve in 50 mL of methanol, dilute with water to volume, and mix to obtain a Standard stock solution. Quantitatively dilute this Standard stock solution with Diluting solution to obtain solutions having suitable known concentrations.
Test solution— Use portions of the solution under test, passed through a 0.4-µm filter, suitably diluted with methanol, and stepwise, if necessary, with Diluting solution to obtain a final mixture consisting of equal parts of methanol and water.
Procedure— Determine the amount of C17H18N2O6 released in the Test solution at each 4-hour interval by employing UV absorption at the wavelength of maximum absorbance at about 338 nm, in 0.5-cm cells. [NOTE—For the 4-hour time period, determine the absorbance at 456 nm, and use this determination to correct for excipient interference.]
Tolerances— The cumulative percentages of the labeled amount of nifedipine (C17H18N2O6), released in vivo and dissolved at the times specified, conform to Acceptance Table 2.
Time (hours) Amount dissolved*
4 between 5% and 17%
8 —
12 between 43% and 80%
16 —
20 —
24 not less than 80%
*  The amount dissolved is expressed in terms of the labeled tablet strength rather than in terms of the labeled total contents.
Test 2— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 2.
Buffer concentrate— Transfer 330.9 g of dibasic sodium phosphate and 38 g of citric acid to a 1-L volumetric flask, add water to dissolve, add 10 mL of phosphoric acid, dilute with water to volume, and mix.
Medium— Mix 125.0 mL of Buffer concentrate and 1 L of 10% sodium lauryl sulfate solution, and dilute to 10 L. Adjust if necessary to a pH of 6.8; 900 mL.
Apparatus 2: 50 rpm, with sinkers (see Figure 1).
Click to View Image
Fig. 1 (printed with permission of the Japanese Pharmacopoeia)
Times: 3, 6, and 12 hours.
Determine the amount of nifedipine (C17H18N2O6) dissolved by employing the following method.
Mobile phase— Prepare a filtered and degassed mixture of acetonitrile and water (70:30). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard solution— Dissolve an accurately weighed quantity of USP Nifedipine RS in methanol to obtain a solution having a known concentration of about 1.11 mg per mL. Dilute quantitatively and stepwise with Medium to obtain a solution having a known concentration of 0.1 mg per mL.
Chromatographic system— The liquid chromatograph is equipped with a 350-nm detector and a 4.0-mm × 125-mm column that contains 3-µm packing L1. The flow rate is about 1.5 mL per minute. The column is maintained at about 40. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the column efficiency is not less than 2000 theoretical plates; the tailing factor is not more than 1.5; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Separately inject equal volumes (about 20 µL) of filtered portions of the Standard solution and the solution under test into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Determine the amount of nifedipine (C17H18N2O6) dissolved.
Tolerances— The percentages of the labeled amount of nifedipine (C17H18N2O6) released in vivo and dissolved at the times specified conform to Acceptance Table 2.
Time (hours) Amount dissolved
3 between 10% and 30%
6 between 40% and 65%
12 not less than 80%
Test 3— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 3.
FOR TABLETS LABELED TO CONTAIN 30 MG OF NIFEDIPINE—
Phase 1:
Medium: 0.05 M phosphate buffer, pH 7.5; 900 mL.
Apparatus 2: 100 rpm.
Time: 1 hour.
Standard solution— Prepare a solution in Medium having an accurately known concentration of about 0.034 mg of USP Nifedipine RS per mL. [Note—If necessary, a volume of methanol, not exceeding 10% of the final volume, can be used to help solubilize nifedipine.]
Procedure— [NOTE—After the run, take the Tablet out of the dissolution vessel, adapt a sinker to it, and transfer the Tablet with the sinker to the dissolution vessel containing the Medium for Phase 2.] Determine the amount of C17H18N2O6 released in Phase 1 from UV absorbances at the wavelength of maximum absorbance at about 238 nm, using filtered portions of the solution under test, in comparison with the Standard solution, using the Medium as the blank.
Phase 2:
Medium: 0.5% sodium lauryl sulfate in simulated gastric fluid without enzyme, pH 1.2; 900 mL.
Apparatus 2: 100 rpm.
Times: 1, 4, 8, and 12 hours.
Standard solution— Prepare a solution in Medium having an accurately known concentration of about 0.034 mg of USP Nifedipine RS per mL. [Note—If necessary, a volume of methanol, not exceeding 10% of the final volume, can be used to help solubilize nifedipine.]
Procedure— Determine the amount of C17H18N2O6 released in Phase 2 from UV absorbances at the wavelength of maximum absorbance at about 238 nm using filtered portions of the solution under test, in comparison with the Standard solution, using Medium as the blank.
Tolerances— The cumulative percentages of the labeled amount of nifedipine (C17H18N2O6), released in vivo and dissolved at the times specified, conform to Acceptance Table 2.
Time (hours) Amount dissolved*
1 not more than 30%
4 between 30% and 55%
8 not less than 60%
12 not less than 80%
*  For each dosage unit, add the amount dissolved in phosphate buffer, pH 7.5 from Phase 1 to the amount dissolved at each time point in Phase 2.
FOR TABLETS LABELED TO CONTAIN 60 MG OF NIFEDIPINE—
Phase 1:
Medium: 0.05 M phosphate buffer, pH 7.5; 900 mL.
Procedure— [NOTE—After the run, take the Tablet out of the dissolution vessel, adapt a sinker to it, and transfer the Tablet with the sinker to the dissolution vessel containing the Medium for Phase 2.] Determine the amount of C17H18N2O6 released in Phase 1 from UV absorbances at the wavelength of maximum absorbance at about 238 nm using filtered portions of the solution under test, in comparison with the Standard solution, using the Medium as the blank.
Apparatus 2: 100 rpm.
Time: 25 minutes.
Standard solution— Prepare a solution in Medium having an accurately known concentration of about 0.067 mg of USP Nifedipine RS per mL. If necessary, a volume of methanol, not exceeding 10% of the final volume, can be used to help solubilize nifedipine.
Phase 2:
Medium: 0.5% sodium lauryl sulfate in simulated gastric fluid without enzyme, pH 1.2; 900 mL.
Apparatus 2: 100 rpm.
Times: 1, 4, 8, and 12 hours.
Standard solution— Prepare a solution in Medium having an accurately known concentration of about 0.067 mg of USP Nifedipine RS per mL. [Note—If necessary, a volume of methanol, not exceeding 10% of the final volume, can be used to help solubilize nifedipine.]
Procedure— Determine the amount of C17H18N2O6 released in Phase 2 from UV absorbances at the wavelength of maximum absorbance at about 238 nm, using filtered portions of the solution under test, in comparison with the Standard solution, using Medium as the blank.
Tolerances— The cumulative percentages of the labeled amount of nifedipine (C17H18N2O6), released in vivo and dissolved at the times specified, conform to Acceptance Table 2.
Time (hours) Amount dissolved*
1 not more than 30%
4 between 40% and 70%
8 not less than 70%
12 not less than 80%
*  For each dosage unit, add the amount dissolved in phosphate buffer, pH 7.5 from Phase 1 to the amount dissolved at each time point in Phase 2.
Test 4— If the product complies with this test, the labeling indicates that the product meets USP Dissolution Test 4.
Medium: 0.5% sodium lauryl sulfate in simulated gastric fluid without enzyme, pH 1.2; 900 mL.
Apparatus 2: 100 rpm.
Times: 1, 4, and 12 hours.
Standard solution— Prepare a solution in Medium having an accurately known concentration of about 0.067 mg of USP Nifedipine RS per mL for Tablets labeled to contain 60 mg, and of about 0.034 mg of USP Nifedipine RS per mL for Tablets labeled to contain 30 mg. [Note—If necessary, a volume of methanol, not exceeding 10% of the final volume, can be used to help solubilize nifedipine.]
Procedure— Determine the amount of C17H18N2O6 released from UV absorbances at the wavelength of maximum absorbance at about 238 nm using filtered portions of the solution under test, in comparison with the Standard solution, using the Medium as the blank.
Tolerances— The cumulative percentages of the labeled amount of nifedipine (C17H18N2O6), released at the times specified, conform to Acceptance Table 2.
FOR TABLETS LABELED TO CONTAIN 30 MG OF NIFEDIPINE
Time (hours) Amount dissolved
1 between 12% and 35%
4 between 44% and 67%
12 not less than 80%
FOR TABLETS LABELED TO CONTAIN 60 MG OF NIFEDIPINE
Time (hours) Amount dissolved
1 between 10% and 30%
4 between 40% and 63%
12 not less than 80%
(Official April 1, 2006)
Uniformity of dosage units 905: meet the requirements.
Related compounds— [NOTE—Conduct this test promptly after preparation of the Standard nifedipine solution and the Test solution.]
Mobile phase— Prepare as directed in the Assay under Nifedipine.
Standard nifedipine solution, Reference solution 1, and Reference solution 2— Prepare as directed in the test for Related compounds under Nifedipine, except to obtain solutions having known concentrations of about 6 µg per mL and 1.5 µg per mL for Reference solution 1 and Reference solution 2, respectively.
System suitability solution— Mix equal volumes of the Standard nifedipine solution, Reference solution 1, and Reference solution 2.
Standard solution— Transfer 5.0 mL of each Reference solution to a container, add 5.0 mL of Mobile phase, and mix. Each mL of this solution contains about 2 µg of USP Nifedipine Nitrophenylpyridine Analog RS and 0.5 µg of USP Nifedipine Nitrosophenylpyridine Analog RS.
Test solution— Use a portion of the Assay preparation.
Chromatographic system (see Chromatography 621)— Prepare as directed in the Assay. Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the resolution, R, between nitrophenylpyridine analog and nitrosophenylpyridine analog is not less than 1.5; the resolution, R, between nitrosophenylpyridine analog and nifedipine is not less than 1.0; and for each analog, the relative standard deviation for replicate injections is not more than 10%.
Procedure— Separately inject equal volumes (about 25 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the percentage of each related compound in the portion of Tablets taken by the formula:
417(C/W)(ri / rS),
in which C is the concentration, in µg per mL, of the appropriate analog USP Reference Standard in the Standard solution; W is the weight, in mg, of nifedipine in the Tablets taken to prepare the Test solution; and ri and rS are the peak responses of the corresponding related compound obtained from the Test solution and the Standard solution, respectively: not more than 2.0% of nifedipine nitrophenylpyridine analog and not more than 0.5% of nifedipine nitrosophenylpyridine analog, both relative to the nifedipine content, are found.
Residual solvents 467: meet the requirements.
(Official January 1, 2007)
Assay— [NOTE—Conduct the Assay promptly after preparation of the Standard preparation and the Assay preparation.]
Mobile phase and Standard preparation— Prepare as directed in the Assay under Nifedipine.
Assay preparation— Select a number of Tablets, equivalent to about 420 mg of nifedipine. Finely powder the Tablets, and transfer the powder to a 250-mL volumetric flask containing 130 mL of water; or transfer the intact Tablets to a 400-mL, high-speed blender cup containing 130 mL of water, homogenize until a uniform suspension is achieved (about 2 minutes), and transfer the suspension with the aid of a mixture of acetonitrile and methanol (1:1) to a 250-mL volumetric flask. Add a mixture of acetonitrile and methanol (1:1) to volume, and stir for 30 minutes. Centrifuge the resulting suspension to obtain a clear supernatant stock solution. Transfer 3.0 mL of the stock solution to a 50-mL volumetric flask, dilute with Mobile phase to volume, mix, and filter to obtain a solution having a concentration of about 0.1 mg of nifedipine per mL. [NOTE—Reserve a portion of this Assay preparation for use as the Test solution in the test for Related compounds.]
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 265-nm detector, a 4.6-mm × 25-cm analytical column that contains packing L1, and a 2.1-mm × 3-cm guard column that contains packing L1. The flow rate is about 1 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the column efficiency is not less than 4000 theoretical plates; the tailing factor is not more than 1.5; and the relative standard deviation for replicate injections is not more than 1.0%.
Procedure— Separately inject equal volumes (about 25 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 nifedipine (C17H18N2O6) in the Tablets taken by the formula:
4167C(rU / rS),
in which C is the concentration, in mg per mL, of USP Nifedipine 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— Staff Liaison : Andrzej Wilk, Ph.D., Senior Scientific Associate
Expert Committee : (MDCV05) Monograph Development-Cardiovascular
USP29–NF24 Page 1531
Pharmacopeial Forum : Volume No. 31(1) Page 168
Phone Number : 1-301-816-8305