Penicillamine Tablets
Action and use
Disease-modifying antirheumatic drug; chelating agent; treatment of Wilson’s disease; heavy metal poisoning; cystinuria.
Definition
Penicillamine Tablets contain Penicillamine. They are coated.
Content of penicillamine, C5H11NO2S
95.0 to 105.0% of the stated amount.
Identification
Tests
Mercuric salts
Not more than 10 ppm, calculated with reference to the content of penicillamine, when determined by the following method. Disperse a quantity of the powdered tablets containing 1 g of Penicillamine in 10 mL of water in a stoppered flask, add 0.2 mL of 9m perchloric acid and swirl to dissolve. Add 1 mL of ammonium pyrrolidinedithiocarbamate solution, mix, add 2 mL of 4-methylpentan-2-one, shake well for 1 minute and add sufficient water to produce 25 mL. Determine by atomic absorption spectrophotometry, Appendix II D, introducing the methylpentanone layer into the flame, measuring at 254 nm and using 4-methylpentan-2-one in place of water. Use mercury standard solution (10 ppm Hg) for the standard solutions, adjusted to contain the same concentrations of 9m perchloric acid, ammonium pyrrolidinedithiocarbamate solution and 4-methylpentan-2-one as the solution being examined.
Penicillamine disulfide
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
0.01% w/v of disodium edetate and 0.2% w/v of methane sulfonic acid.
In the chromatogram obtained with solution (1):
the area of any peak corresponding to penicillamine disulfide is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (1.0%).
Assay
Weigh and powder 20 tablets. Dissolve a quantity of the powder containing 0.1 g of Penicillamine as completely as possible in 50 mL of water and filter. Add to the filtrate 5 mL of 1m sodium hydroxide and 0.2 mL of a 0.1% w/v solution of dithizone in ethanol (96%) and titrate with 0.02m mercury(ii) nitrate VS. Each mL of 0.02m mercury(ii) nitrate VS is equivalent to 5.968 mg of C5H11NO2S.