Penicillamine Capsules
» Penicillamine Capsules contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C5H11NO2S.
Packaging and storage— Preserve in tight containers.
USP Reference standards 11
USP Penicillamine RS Click to View Structure
USP Penicillamine Disulfide RS
    C10H20N2O4S2    
Identification— The contents of the Capsules respond to Identification test A under Penicillamine Tablets and to Identification test C under Penicillamine.
Dissolution 711
Medium: 0.1 N hydrochloric acid; 900 mL.
Apparatus 1: 100 rpm.
Time: 30 minutes.
procedure for a pooled sample
Dilute hydrochloric acid— Dilute 37 mL of hydrochloric acid with water to 1 L.
Ammonium sulfamate reagent— Dissolve 250 mg of ammonium sulfamate in 100 mL of Dilute hydrochloric acid.
N-(1-Naphthyl)ethylenediamine dihydrochloride reagent— Dissolve 100 mg of N-(1-naphthyl)ethylenediamine dihydrochloride in 100 mL of Dilute hydrochloric acid.
Sulfanilamide–mercuric chloride reagent— Dissolve 100 mg of sulfanilamide and 100 mg of mercuric chloride in 100 mL of Dilute hydrochloric acid.
Sodium nitrite reagent— Dissolve 200 mg of sodium nitrite in 100 mL of dilute sulfuric acid (1 in 50). Prepare fresh.
Standard solution— Dissolve an accurately weighed quantity of USP Penicillamine RS in 0.1 N hydrochloric acid to obtain a solution having a known concentration of about 250 µg per mL.
Procedure— Pipet an aliquot of the filtered test solution, estimated to contain about 278 µg of penicillamine, into a 100-mL volumetric flask. Into a similar flask pipet an equivalent volume of 0.1 N hydrochloric acid to provide a reagent blank, and into a third 100-mL volumetric flask pipet 1 mL of Standard solution. Treat each flask as follows. Add by pipet 3 mL of Sodium nitrite reagent, and mix by swirling occasionally. After 5 minutes, add 10 mL of Ammonium sulfamate reagent, swirl, and allow to stand for an additional 5 minutes. Add 5 mL of Sulfanilamide–mercuric chloride reagent, swirl, and immediately add 10 mL of N-(1-Naphthyl)ethylenediamine dihydrochloride reagent. Dilute with water to volume, and mix. Determine the absorbances of both solutions in 1-cm cells at the wavelength of maximum absorbance at about 540 nm, with a suitable spectrophotometer, against the reagent blank. Calculate the percentage dissolution of the Capsule taken by the formula:
90(C/WV)(AU / AS)
in which C is the concentration, in µg per mL, of USP Penicillamine RS in the Standard solution; W is the labeled quantity, in mg, of penicillamine in the Capsule; V is the volume, in mL, of the aliquot of test solution used; and AU and AS are the absorbances of the solutions from the test solution and the Standard solution, respectively.
Tolerances— Not less than 80% (Q) of the labeled amount of C5H11NO2S is dissolved in 30 minutes.
procedure for a unit sample —
Buffer solution— Prepare a 50-mM solution of monobasic potassium phosphate buffer, pH 3.0.
Mobile phase— Prepare a filtered and degassed mixture of Buffer solution and methanol (97:3). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard solution— Prepare a solution of USP Penicillamine RS in 0.1 N hydrochloric acid having a known concentration corresponding to the content of 1 Capsule dissolved in 900 mL of Medium.
Resolution solution— Prepare a solution of USP Penicillamine Disulfide RS in 0.1 N hydrochloric acid having a known concentration of about 0.002 mg per mL.
Test solution— Proceed as directed for Procedure for Capsules, Uncoated Tablets, and Plain Coated Tablets under Dissolution 711. After 30 minutes, withdraw about 10 mL of solution from each vessel, and immediately pass each aliquot through a 0.45-µm polyvinylidene difluoride filter paper. Discard the first 2 mL of filtered solution, and chromatograph the remaining filtrate.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 210-nm detector and a 4.6-mm × 15-cm column that contains 5-µm packing L1. The flow rate is about 1.0 mL per minute. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the tailing factor is not more than 2.0, and the relative standard deviation for replicate injections is not more than 2.0%. Chromatograph the Resolution solution, and record the peak responses as directed for Procedure: the resolution, R, between penicillamine and penicillamine disulfide is not less than 2.0.
Procedure— Separately inject equal volumes (about 30 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 amount, in percentage, of C5H11NO2S released by the formula:
Click to View Image
in which rU and rS are the peak areas obtained from the Test solution and the Standard solution, respectively; CS is the concentration, in mg per mL, of the Standard solution; 900 is the volume, in mL, of Medium; 100 is the conversion factor to percentage; and LC is the label claim, in mg, for each Capsule.
Tolerances— Not less than 80% (Q) of the labeled amount of C5H11NO2S is dissolved in 30 minutes.
Uniformity of dosage units 905: meet the requirements.
Loss on drying 731 Dry about 100 mg of Capsule contents, accurately weighed, in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5 mm of mercury at 60 for 3 hours: it loses not more than 1.0% of its weight.
Limit of penicillamine disulfide—
Diluent, Mobile phase, and Resolution solution— Proceed as directed in the Assay under Penicillamine
Standard preparation— Dissolve an accurately weighed quantity of USP Penicillamine Disulfide RS in Diluent to obtain a solution having a known concentration of about 0.025 mg per mL.
Test preparation— Use the Assay preparation.
Chromatographic system— Proceed as directed in the Assay under Penicillamine. Chromatograph the Standard preparation, and record the penicillamine disulfide peak responses as directed for Procedure: the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— [note—Use peak areas where peak responses are indicated. ] Separately inject equal volumes (about 20 µL) of the Standard preparation and the Test preparation into the chromatograph, record the chromatograms, and measure the responses for the penicillamine disulfide peaks. Calculate the percentage of penicillamine disulfide (C10H20N2O4S2) in the Capsules taken by the formula:
100(C/L)(V/N)(rU / rS)
in which C is the concentration, in mg per mL, of USP Penicillamine Disulfide RS in the Standard preparation; L is the quantity, in mg, of penicillamine in each Capsule based on the labeled amount; V is the volume, in mL, of the volumetric flask used to prepare the Assay preparation in the Assay; N is the number of Capsules used to prepare the Assay preparation in the Assay; and rU and rS are the penicillamine disulfide peak responses obtained from the Test preparation and the Standard preparation, respectively: not more than 2.0% of penicillamine disulfide is found.
Assay—
Diluent, Mobile phase, Resolution solution, Standard preparation, and Chromatographic system— Proceed as directed in the Assay under Penicillamine.
Assay preparation— Carefully open and transfer the contents of not fewer than 10 Capsules, accurately counted, to a suitable volumetric flask of such volume that when treated as described below, a solution is obtained that contains about 1.25 mg of penicillamine per mL. Add the empty Capsule shells to the flask, and add sufficient Diluent to the flask to fill it to about three-fourths of its capacity. Shake for 1 minute, and allow the mixture to stand for 90 minutes. Dilute with Diluent to volume, and mix. Filter a portion of this solution through a suitable filter of 1 µm or finer porosity, and use the clear filtrate as the Assay preparation.
Procedure— Proceed as directed for Procedure in the Assay under Penicillamine. Calculate the quantity, in mg, of penicillamine (C5H11NO2S) in each Capsule taken by the formula:
C(V/N)(rU / rS)
in which C is the concentration, in mg per mL, of USP Penicillamine RS in the Standard preparation; V is the volume, in mL, of the volumetric flask used to prepare the Assay preparation; N is the number of Capsules used to prepare the Assay preparation; and rU and rS are the penicillamine peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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