Edition: BP 2025 (Ph. Eur. 11.6 update)
General Notices
Dipotassium Phosphate Injection
DEFINITION
Dipotassium Hydrogen Phosphate Injection is a sterile solution of Dipotassium Hydrogen Phosphate in Water for Injections.
The injection complies with the requirements stated under Parenteral Preparations and with the following requirements.
Content of dipotassium hydrogen phosphate, K2HPO4
95.0 to 105.0% of the stated amount.
IDENTIFICATION
Yields the reactions characteristic of potassium salts and reaction B characteristic of phosphates, Appendix VI.
TESTS
Alkalinity
pH, 9.0 to 10.0, Appendix V L.
ASSAY
Dilute, if necessary, a volume of the injection with sufficient carbon dioxide-free water to produce a solution containing 8.71% w/v (1 millimole of potassium ion per mL) of dipotassium hydrogen phosphate. Titrate 20 mL with 0.5M hydrochloric acid VS using a mixture of 4 volumes of bromocresol green solution and 1 volume of methyl red solution as indicator. Each mL of 0.5M hydrochloric acid VS is equivalent to 87.1 mg of K2HPO4.
LABELLING
The label states (1) the percentage w/v of Dipotassium Phosphate; (2) the concentration of the potassium ion in millimoles.
