Piperazine Phosphate Tablets

General Notices

Action and use

Antihelminthic.

Definition

Piperazine Phosphate Tablets contain Piperazine Phosphate.

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

Content of piperazine phosphate, C₄H₁₀N₂,H₃PO₄,H₂O

92.5 to 107.5% of the stated amount.

Identification

Extract a quantity of the powdered tablets containing 1 g of Piperazine Phosphate with 20 mL of water and filter. The filtrate complies with the following tests.

A. Dilute 1 mL to 5 mL with water, add 0.5 g of sodium hydrogen carbonate, 0.5 mL of a freshly prepared 5% w/v solution of potassium hexacyanoferrate(iii) and 0.1 mL of mercury, shake vigorously for 1 minute and allow to stand for 20 minutes. A reddish colour is produced slowly.

B. To 4 mL add 1 mL of hydrochloric acid and, with stirring, 1 mL of a 50% w/v solution of sodium nitrite and cool in ice for 15 minutes, stirring if necessary to induce crystallisation. The melting point of the crystals, after washing with 10 mL of cold water and drying at 105°, is about 159°, Appendix V A.

C. Yields the reactions characteristic of phosphates, Appendix VI.

Assay

Weigh and powder 20 tablets. Shake a quantity of the powder containing 0.15 g of Piperazine Phosphate with 10 mL of water for 1 hour, filter and wash the residue with two 10 mL quantities of water. To the combined extract and washings add 5 mL of 1m sulfuric acid and 50 mL of picric acid solution R1, bring to the boil, allow to stand for several hours, filter through a sintered-glass crucible (ISO 4793, porosity grade 4, is suitable) and wash the residue with successive 10 mL quantities of a mixture of equal volumes of a saturated solution of picric acid and water until the washings are free from sulfate. Wash the residue with five 10 mL quantities of absolute ethanol and dry to constant weight at 100° to 105°. Each g of residue is equivalent to 0.3714 g of C₄H₁₀N₂,H₃PO₄,H₂O.