Pyrazinamide Tablets

General Notices

Action and use

Antituberculosis drug.

Definition

Pyrazinamide Tablets contain Pyrazinamide.

The tablets comply with the requirements stated under Tablets and with the following requirements.

Content of pyrazinamide, C5H5N3O

95.0 to 105.0% of the stated amount.

Identification

Shake a quantity of the powdered tablets containing 0.25 g of Pyrazinamide with 20 mL of absolute ethanol, filter, evaporate the filtrate to dryness and dry the residue at 105° for 30 minutes. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of pyrazinamide (RS 306).

Related substances

Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.

(1) Shake a quantity of the powdered tablets containing 0.10 g of Pyrazinamide with 50 mL of a mixture of 1 volume of methanol and 9 volumes of chloroform, filter, evaporate to dryness and dissolve the residue in sufficient of the same solvent mixture to produce 10 mL.
(2) Dilute 1 volume of solution (1) to 500 volumes with a mixture of 1 volume of methanol and 9 volumes of chloroform.
chromatographic conditions
(a) Use as the coating silica gel GF254.
(b) Use the mobile phase as described below.
(c) Apply 20 µL of each solution.
(d) Develop the plate to 10 cm.
(e) After removal of the plate, dry in air and examine immediately under ultraviolet light (254 nm).
mobile phase

20 volumes of glacial acetic acid, 20 volumes of water and 60 volumes of butan-1-ol.

limits

Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (0.2%).

Assay

Weigh and powder 20 tablets. To a quantity of the powder containing 0.1 g of Pyrazinamide add 200 mL of water, allow to stand for 10 minutes, swirling occasionally, mix with the aid of ultrasound for 10 minutes and dilute to 500 mL with water. Filter and discard the first 20 mL of filtrate. Dilute 5 mL of the filtrate to 100 mL with water and measure the absorbance of the resulting solution at the maximum at 268 nm, Appendix II B. Calculate the content of C5H5N3O taking 650 as the value of A(1%, 1 cm) at the maximum at 268 nm.