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Pyrazinamide Tablets
» Pyrazinamide Tablets contain not less than 93.0 percent and not more than 107.0 percent of the labeled amount of pyrazinamide (C5H5N3O).
Packaging and storage
Preserve in well-closed containers.
Identification
A:
To a quantity of powdered Tablets, equivalent to about 1 g of pyrazinamide, add about 75 mL of isopropyl alcohol, heat on a steam bath, and filter while hot. Allow to cool, filter the crystals that form, and dry at 105
B:
The dried crystals obtained in Identification test A meet the requirements for Identification test B under Pyrazinamide.
C:
To 20 mg of the dried crystals obtained in Identification test A add 5 mL of 5 N sodium hydroxide, and heat gently over an open flame: the odor of ammonia is perceptible.
Dissolution
Medium:
water; 900 mL.
Apparatus 2:
50 rpm.
Time:
45 minutes.
Procedure
Determine the amount of C5H5N3O dissolved by employing UV absorption at the wavelength of maximum absorbance at about 268 nm on filtered portions of the solution under test, suitably diluted with Dissolution Medium, if necessary, in comparison with a Standard solution having a known concentration of USP Pyrazinamide RS in the same Medium.
Tolerances
Not less than 75% (Q) of the labeled amount of C5H5N3O is dissolved in 45 minutes.
Uniformity of dosage units
Assay
Mobile phase
Prepare pH 8.0 phosphate buffer (see Buffer Solutions in the section Reagents, Indicators, and Solutions), and adjust with phosphoric acid to a pH of 3.0. Mix 10 mL of acetonitrile with 1 L of this solution, filter, and degas. Make adjustments if necessary (see System Suitability under Chromatography
Standard preparation
Transfer an accurately weighed quantity of USP Pyrazinamide RS to a suitable volumetric flask, dissolve in water, sonicating to dissolve, dilute with water to volume, and mix to obtain a solution having a known concentration of about 0.1 mg per mL. Transfer 20.0 mL of the solution to a 50-mL volumetric flask, dilute with water to volume, and mix.
System suitability solution
Transfer 1 mL of hydrochloric acid to a 5-mL volumetric flask, dilute with Standard preparation to volume, and mix. Keep this solution on a boiling water bath for 5 minutes, and cool.
Assay preparation
Accurately weigh not fewer than 20 Tablets, and grind to a fine powder. Transfer an accurately weighed quantity of the powder, equivalent to about 100 mg of pyrazinamide, to a 500-mL volumetric flask, add 300 mL of water, and sonicate for 10 minutes. Dilute with water to volume, and mix. Filter a portion of this solution, discarding the first few mL of the filtrate. Transfer 20.0 mL of this filtrate to a 100-mL volumetric flask, dilute with water to volume, and mix.
Chromatographic system
(see Chromatography
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 pyrazinamide (C5H5N3O) in the portion of Tablets taken by the formula:
2.5C(rU / rS)
in which C is the concentration, in µg, of USP Pyrazinamide 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.
USP35NF30 Page 4488
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