Procarbazine Hydrochloride Capsules

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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Procarbazine Hydrochloride Capsules

» Procarbazine Hydrochloride Capsules contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of procarbazine (C₁₂H₁₉N₃O).

Packaging and storage—Preserve in tight, light-resistant containers.

USP Reference standards 〈11〉—

USP Procarbazine Hydrochloride RS

1 Identification—

The polarogram of the solution employed for measurement in the Assay exhibits a half-wave potential (E½) within ±0.03 volt of that of USP Procarbazine Hydrochloride RS, similarly measured (E½ is about −0.16 volt against a saturated calomel electrode).

Dissolution 〈711〉—

Medium: water; 900 mL.

Apparatus 2: 50 rpm.

Time: 45 minutes.

Procedure—Determine the amount of procarbazine (C₁₂H₁₉N₃O) dissolved from UV absorbances at the wavelength of maximum absorbance at about 233 nm of filtered portions of the solution under test, suitably diluted with water, in comparison with a Standard solution having a known concentration of USP Procarbazine Hydrochloride RS in the same medium.

Tolerances—Not less than 75% (Q) of the labeled amount of C₁₂H₁₉N₃O is dissolved in 45 minutes.

Uniformity of dosage units 〈905〉: meet the requirements.

2 Assay—

pH 12 buffer—Dissolve 5.43 mL of phosphoric acid, 4.60 mL of glacial acetic acid, and 4.95 g of boric acid in water to make 2000 mL. To 100 mL of this solution add 100 mL of 0.2 N sodium hydroxide. Prior to use, deaerate this solution by bubbling with scrubbed nitrogen.

Procedure—[Note—Use low-actinic glassware throughout this procedure.] Weigh the contents of not less than 20 Capsules, and determine the average weight per capsule. Mix the combined contents to obtain a homogeneous sample. Transfer an accurately weighed portion of this powder, equivalent to about 60 mg of procarbazine hydrochloride, to a 100-mL volumetric flask that previously has been flushed with nitrogen. Dissolve in pH 12 buffer, dilute with pH 12 buffer to volume, and centrifuge a portion of this solution at about 1500 rpm for about 3 minutes. Transfer 10 mL to 15 mL of the solution to a polarographic cell that is regulated at 25 ± 0.1°. Deaerate by bubbling scrubbed nitrogen through the solution for 5 minutes. Insert the dropping mercury electrode of a suitable polarograph, which is capable of measuring a current of 10 microamperes, using an average capillary, a mercury column height of 56 cm, and a drop rate of approximately 4 per second. Record the polarogram from −0.75 volt to +0.25 volt, using a saturated calomel electrode as the reference electrode. Determine the height of the current at a point 200 mV anodic of the half-wave potential. Calculate the quantity, in mg, of C₁₂H₁₉N₃O in the portion of Capsule contents taken by the formula:

100(0.8585C)[i₁ / i₂]

in which 0.8585 is the ratio of the molecular weight of procarbazine to that of procarbazine hydrochloride, i₁ is the observed current of the solution from the Capsule contents and i₂ is that determined similarly in a solution of USP Procarbazine Hydrochloride RS, the concentration of which is C mg per mL (about 600 µg per mL).