Verapamil Hydrochloride Extended-Release Tablets
» Verapamil Hydrochloride Extended-Release Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of verapamil hydrochloride (C27H38N2O4·HCl).
Packaging and storage
Preserve in tight, light-resistant containers.
Labeling
The labeling indicates the Dissolution Test with which the product complies.
Identification, Infrared Absorption 197F
Prepare analytical specimens as follows.
Test specimen
Crush 1 Tablet, and transfer the powder to a volumetric flask of suitable size so that the final concentration is about 1.2 mg of verapamil hydrochloride per mL. Add 0.05 N hydrochloric acid to about 75% of the final volume, and dissolve by heating, with stirring, for 40 minutes. Cool, and dilute with 0.05 N hydrochloric acid to volume. Filter, and transfer 40 mL of the filtrate to a 125-mL separatory funnel. Add 4 mL of 1 N sodium hydroxide, and extract with 20 mL of chloroform, shaking for 2 minutes. Pass the chloroform extract through a filter containing anhydrous sodium sulfate, and collect the filtrate in a porcelain dish. Rinse with an additional 10 mL of chloroform, collecting the rinsing in the same porcelain dish. Evaporate on a steam bath with the aid of a current of air to dryness, and dry the oily residue at 105 for 30 minutes.
Standard specimen
Dissolve about 48 mg of USP Verapamil Hydrochloride RS, accurately weighed, in 25 mL of water. Transfer to a 125-mL separatory funnel, add 2 mL of 1 N sodium hydroxide, and extract with 25 mL of chloroform, shaking for two minutes. Proceed as directed for the Test specimen, beginning with Pass the chloroform extract.
Dissolution 711
test 1
If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 1. Proceed as directed for Procedure for Method B under Apparatus 1 and Apparatus 2, Delayed-Release Dosage Forms.
Acid stage
Using 900 mL of simulated gastric fluid TS (without enzyme), conduct this stage of the test for 1 hour.
Buffer stage
Using 900 mL of simulated intestinal fluid TS (without enzyme), conduct this stage of the test for 7 hours.
Apparatus 2:
50 rpm.
Times:
Acid stage1 hour; Buffer stage2, 3.5, 5, and 8 hours.
Procedure
Wrap each Tablet in a wire helix to prevent the Tablets from floating. After 1 hour in the Acid stage, withdraw a specimen for analysis, and carefully transfer the dosage form, including the wire helix, to a vessel containing the Buffer stage medium, which has been previously warmed to 37 ± 0.5. Filter a portion of the solution under test at each time interval, using a suitable glass microfiber filter paper. [noteUse only filters that have been shown not to absorb verapamil.] Dilute with water, if necessary, the filtered portions of the solutions under test at the 1-hour interval and with 0.1 N hydrochloric acid at the 2-, 3.5-, 5-, and 8-hour intervals. Determine the amounts of C27H38N2O4·HCl dissolved by employing UV absorption at the wavelength of maximum absorbance at about 278 nm, using 0.01 N hydrochloric acid as the blank, by comparison with a Standard solution having a known concentration of USP Verapamil Hydrochloride RS in 0.01 N hydrochloric acid.
Tolerances
The percentage of the labeled amount of C27 H38N2O4·HCl dissolved at the times specified conforms to Acceptance Table 2.
for products labeled to contain 180 mg or 240 mg:
for products labeled to contain 120 mg:
test 2
If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 2. Proceed as directed for Test 1, except that for Procedure, the Tablet is not required to be wrapped in a wire helix.
Times and Tolerances
The percentage of the labeled amount of C27H38N2O4·HCl dissolved at the times specified conforms to Acceptance Table 2.
for products labeled to contain 120 mg or 240 mg:
for products labeled to contain 180 mg:
test 3
If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 3. Proceed as directed for Test 1.
Times and Tolerances
The percentage of the labeled amount of C27H38N2O4·HCl dissolved at the times specified conforms to Acceptance Table 2.
test 4
If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 4.
Medium:
simulated intestinal fluid TS (without enzyme); 50 mL.
Apparatus 7 (see Drug Release 724):
20 cycles per minute.
Procedure
Scrape about 2 mm × 2 mm of the coating from the side edge of the Tablet under test. Glue the system to a plastic rod sample holder at the area where the color has been removed. Attach each plastic sample holder to an arm of the apparatus, which reciprocates at an amplitude of about 2 cm and 15 to 30 cycles per minute. The Tablet is continuously immersed in tubes containing 50 mL of Medium at 37. 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. Remove the tubes after the last test interval, and allow them to cool to room temperature. Add 2.0 mL of 1.0 M phosphoric acid to each tube, and dilute with water to 50 mL. Stir and mix each tube thoroughly. Determine the amount of C27H38N2O4·HCl dissolved by employing UV absorption at the wavelength of maximum absorbance at about 278 nm on filtered portions of the solution under test, suitably diluted with Medium, if necessary, in comparison with a Standard solution having a known concentration of USP Verapamil Hydrochloride RS in the same Medium.
Times and Tolerances
The percentages of the labeled amount of C27H38N2O4·HCl dissolved at the times specified conform to Acceptance Table 2.
test 5
If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 5.
Phosphate buffer solution
Dissolve 6.8 g of monobasic potassium phosphate in 250 mL of water. Add 190 mL of 0.2 N sodium hydroxide in 400 mL of water, adjust with 0.2 N sodium hydroxide to a pH of 7.5 ± 0.1, dilute with water to 1000 mL, and mix.
Medium:
Phosphate buffer solution; 900 mL.
Apparatus 2:
50 rpm.
Procedure
Determine the amount of C27H38N2O4·HCl dissolved by employing UV absorption at the wavelength of maximum absorbance at about 278 nm on filtered portions of the solution under test, suitably diluted with Medium, if necessary, in comparison with a Standard solution having a known concentration of USP Verapamil Hydrochloride RS in the same Medium.
Times and Tolerances
The percentages of the labeled amount of C27H38N2O4·HCl dissolved at the times specified conform to Acceptance Table 2.
Uniformity of dosage units 905:
meet the requirements.
Chromatographic purity
Buffer solution, Mobile phase, Standard preparation, System suitability solution, and Chromatographic system
Proceed as directed in the Assay.
Test preparation
Prepare as directed for Assay preparation in the Assay.
Procedure
Proceed as directed for Procedure in the Assay. Calculate the percentage of each impurity in the portion of Tablets taken by the formula:
100(ri / rs)
in which ri is the peak response for each impurity, and rs is the sum of the responses of all of the peaks: not more than 0.5% of any individual impurity is found, and the sum of all impurities is not more than 1.0%.
Assay
Buffer solution
Transfer 0.82 g of sodium acetate to a 1000-mL volumetric flask, add 33 mL of glacial acetic acid, dilute with water to volume, and mix.
Mobile phase
Prepare a filtered and degassed mixture of Buffer solution, acetonitrile, and 2-aminoheptane (70:30:0.5). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation
Dissolve an accurately weighed quantity of USP Verapamil 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 1.2 mg per mL.
System suitability solution
Dissolve suitable quantities of USP Verapamil Hydrochloride RS and USP Verapamil Related Compound B RS in Mobile phase to obtain a solution containing about 2.5 and 2.0 mg per mL, respectively.
Assay preparation
Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 240 mg of verapamil hydrochloride, to a 200-mL volumetric flask, and add about 160 mL of Mobile phase. Sonicate for 15 minutes, stir for 15 minutes, dilute with Mobile phase to volume, and mix. Centrifuge a portion for 20 minutes, and use as the Assay preparation.
Chromatographic system
(see Chromatography 621)The liquid chromatograph is equipped with a 278-nm detector and a 4.6-mm × 15-cm column that contains packing L1. The flow rate is about 1.0 mL per minute. Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the resolution, R, between verapamil and verapamil related compound B is not less than 1.5. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the relative standard deviation for replicate injections is not more than 2.0%.
Procedure
Separately inject equal volumes (about 10 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 verapamil hydrochloride (C27H38N2O4·HCl) in the portion of Tablets taken by the formula:
200C(rU / rS)
in which C is the concentration, in mg per mL, of USP Verapamil 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.
Chromatographic Column
USP32NF27 Page 3855
Pharmacopeial Forum: Volume No. 33(4) Page 683
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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