(Official April 1, 2006)

Test 1: If the product complies with this test, the labeling indicates that it meets USP Drug Release Test 1.

Medium: water; 1000 mL.

Apparatus 1: 100 rpm.

Times: 3, 6, and 12 hours.

Solvent A— Dissolve 1.9 g of sodium 1-hexanesulfonate in 700 mL of water, add 50 mL of 1 M monobasic sodium phosphate and 20 mL of 0.25 N triethylammonium phosphate (prepared by mixing 500 mL of a solution containing 25.3 g of triethylamine and 500 mL of a solution containing 9.6 g of phosphoric acid), and mix. Dilute with water to 1 L, and mix.

Mobile phase— Prepare a filtered and degassed mixture of Solvent A and methanol (100:82). Make adjustments if necessary (see Chromatography 621).

Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 210-nm detector and a 4.6-mm × 25-cm column that contains packing L1. The flow rate is about 1.5 mL per minute. Chromatograph replicate injections of a Standard solution, and record the peak responses as directed for Procedure: the tailing factor for the analyte peak is not more than 1.5, and the relative standard deviation for replicate injections is not more than 2%.

Procedure— Inject an accurately measured volume (about 50 µL) of a filtered portion of the solution under test into the chromatograph, record the chromatogram, and measure the response for the major peak. Calculate the quantity of C9H13NO·HCl dissolved by comparison with a Standard solution having a known concentration of USP Phenylpropanolamine Hydrochloride RS in the same Medium and similarly chromatographed.

Tolerances— The percentages of the labeled amount of C9H13NO·HCl dissolved at the times specified conform to Acceptance Table 1.

Test 1— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 1.

Medium: water; 1000 mL.

Apparatus 1: 100 rpm.

Times: 3, 6, and 12 hours.

Solvent A— Dissolve 1.9 g of sodium 1-hexanesulfonate in 700 mL of water, add 50 mL of 1 M monobasic sodium phosphate and 20 mL of 0.25 N triethylammonium phosphate (prepared by mixing 500 mL of a solution containing 25.3 g of triethylamine and 500 mL of a solution containing 9.6 g of phosphoric acid), and mix. Dilute with water to 1 L, and mix.

Mobile phase— Prepare a filtered and degassed mixture of Solvent A and methanol (100:82). Make adjustments if necessary (see System Suitablity under Chromatography 621).

Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 210-nm detector and a 4.6-mm × 25-cm column that contains packing L1. The flow rate is about 1.5 mL per minute. Chromatograph replicate injections of a Standard solution, and record the peak responses as directed for Procedure: the tailing factor for the analyte peak is not more than 1.5, and the relative standard deviation for replicate injections is not more than 2%.

Procedure— Inject an accurately measured volume (about 50 µL) of a filtered portion of the solution under test into the chromatograph, record the chromatogram, and measure the response for the major peak. Calculate the quantity of C9H13NO·HCl dissolved by comparison with a Standard solution having a known concentration of USP Phenylpropanolamine Hydrochloride RS in the same Medium and similarly chromatographed.

Tolerances— The percentages of the labeled amount of C9H13NO·HCl dissolved at the times specified conform to Acceptance Table 2

(Official April 1, 2006)

(Official January 1, 2007)

Mobile phase— [NOTE—Prepare the Mobile phase one day prior to use.] Prepare a filtered and degassed mixture of water, methanol, 10% tetramethylammonium hydroxide, and phosphoric acid (700:300:14:3.5). Make adjustments if necessary (see Chromatography 621).

Internal standard solution— Prepare a solution of Theophylline in methanol having a final concentration of about 0.1 mg per mL.

Standard preparation— Prepare a solution of USP Phenylpropanolamine Hydrochloride RS in Internal standard solution having an accurately known concentration of 3 mg per mL.

Assay preparation— Transfer the accurately weighed contents of a counted number of Capsules, equivalent to about 750 mg of phenylpropanolamine hydrochloride, to a container. Add 250.0 mL of Internal standard solution, mix, sonicate for 30 minutes, allow to stand overnight, and filter.

Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 254-nm detector and a 4-mm × 30-cm column that contains packing L11. The flow rate is about 1.5 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 resolution, R, between phenylpropanolamine and theophylline is not less than 5.0.

Procedure— Separately inject equal volumes (about 5 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. The relative retention times are about 0.6 for phenylpropanolamine and 1.0 for theophylline. Calculate the quantity, in mg, of phenylpropanolamine hydrochloride (C9H13NO·HCl) in each of the Capsules taken by the formula: in which C is the concentration, in mg per mL, of USP Phenylpropanolamine Hydrochloride RS in the Standard preparation; N is the number of Capsules taken; and RU and RS are the peak response ratios obtained from the Assay preparation and the Standard preparation, respectively.