Identification—
Transfer a quantity of powdered Tablets, equivalent to about 50 mg of nadolol, to a conical flask. Add 10 mL of 0.1 N hydrochloric acid, stir for 30 minutes, using a magnetic stirrer, and place in an ultrasonic bath for an additional 30 minutes. Centrifuge, and use the supernatant for the test solution. Apply, as streaks, 100 µL of the test solution and 100 µL of a Standard solution of
USP Nadolol RS in 0.1 N hydrochloric acid having a concentration of about 5 mg per mL to a thin-layer chromatographic plate (see
Chromatography 
621
) coated with a 0.25-mm layer of chromatographic silica gel mixture. Develop the chromatogram in a solvent system consisting of acetone, chloroform, and 2 N ammonium hydroxide (8:1:1) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the developing chamber, allow the solvent to evaporate, and examine the chromatogram under short-wavelength UV light: the
RF value of the principal spot obtained from the test solution corresponds to that obtained from the Standard solution.
Dissolution 711—
Medium:
0.01 N hydrochloric acid; 900 mL.
Apparatus 1:
100 rpm.
Time:
50 minutes.
Procedure—
Determine the amount of C
17H
27NO
4 dissolved, employing the procedure set forth in the
Assay, except to prepare the
Mobile phase using 560 mL of methanol and 1440 mL of water instead of 700 mL and 1300 mL, respectively, and adjusting with 0.1 N hydrochloric acid to a pH of 2.5. Use 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 Nadolol RS in the same
Medium.
Tolerances—
Not less than 80% (Q) of the labeled amount of C17H27NO4 is dissolved in 50 minutes.
Assay—
Mobile phase—
Prepare a filtered and degassed mixture of 700 mL of methanol and 1300 mL of water containing 5.84 g of sodium chloride and 1.0 mL of 0.1 N hydrochloric acid.
Standard preparation—
Dissolve an accurately weighed quantity of
USP Nadolol RS in
Mobile phase to obtain a solution having a known concentration of about 0.2 mg per mL.
Assay preparation—
Weigh and finely powder not less than 20 Tablets. Weigh accurately a portion of the powder, equivalent to about 20 mg of nadolol, and transfer to a 100-mL volumetric flask. Add about 75 mL of Mobile phase, place in an ultrasonic bath for 15 minutes, shaking intermittently, add Mobile phase to volume, and mix. Clarify the solution by filtration or centrifugation.
Chromatographic system
(see
Chromatography 621)—The liquid chromatograph is equipped with a 220-nm detector and a 4.6-mm × 25-cm column that contains packing L16. The flow rate is about 1 mL per minute. Chromatograph replicate injections of the
Standard preparation, and record the peak responses as directed for
Procedure: the relative standard deviation is not more than 2.0%; and the tailing factor for the nadolol peak is not more than 3.
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 major peaks. Calculate the quantity, in mg, of nadolol (C
17H
27NO
4) in the portion of Tablets taken by the formula:
100C(rU / rS),
in which
C is the concentration, in mg per mL, of
USP Nadolol RS in the
Standard preparation; and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.
