Pyrazinamide tablets

Pseudoephedrine Tablets (60 mg) Pyrazinamide Tablets (500 mg), DC Pyrazinamide Tablets (500 mg), WG Pyridoxine see Vitamin Bg... 

Oral 100, 300 mg tablets syrup, 50 mg/5 mL Parenteral 100 mg/mLfor injection Pyrazinamide (generic)... 

According to the USP, pyrazinamide powder contains not less than 99.0% and not more than 101.0% of C5H5N3O, calculated on the anhydrous basis. This is determined using a titration method. This is a tedious and difficult method to perform accurately for the dmg in p oducts owing to the interference of excipients. Therefore, the assay method of pyrazinamide in tablets requires HPLC analysis to ensure that these tablets contain not less than 93.0% and not more than 107.0% of the labeled amount of pyrazinamide (C5H5N3O). 

Most pharmacopoeias specify that ethambutol hydrochloride contains not less than 98.0% and not more than 100.5% of C10H24N2O2 2HCI, calculated on the dried basis. Pharmaceutical products such as tablets must contain not less than 95.0% and not more than 105.0% of the labeled amount.As for pyrazinamide, the main pharmacopoeia assay method for ethambutol is a titration method. However, an HPLC method is used for the assay of ethambutol HCl in tablets.This method requires that a liquid chromatograph equipped with a 200-nm detector and a 4.6 mm X 15 cm base-deactivated column that contains 5 p,m porous silica particles, 3-10 p,m in diameter, with chemically bonded nitrile groups (CN, LIO) is used. The mobile phase is a mixture of 1.0 ml of triethylamine and 1 L of water, adjusted with phosphoric acid to a pH of 7.0. The flow rate is about 1.0 ml/min. Separately inject equal volumes (about 50 p.1) of standard preparations and the assay preparations into the chromatograph, record the chromatograms, and measure the responses for the major peaks and calculate the quantity, in mg, of ethambutol hydrochloride present in the tablets from the peak responses obtained from the assay preparation and the standard preparation, respectively. The tailing factor must not be more than 2.0, and the relative standard deviation for replicate injections not more than 2.0%. 

WHO. International pharmacopoeia monograph on rifampicin, isoniazid, pyrazinamide and ethambutol hydrochloride tablets. Working document QAS/04.097 rev Oct 05. Quality Assurance Safety Medicines (QSM), Department of Essential Drugs and Medicines Policy (EDM). WHO Geneva, October, 2005. 

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