Packaging and storage—
Preserve in single-dose containers, preferably of Type I glass.
Labeling—
The label states the sodium content in terms of milliequivalents in a given volume, and states also the phosphorus content in terms of millimoles in a given volume. Label the Injection to indicate that it is to be diluted to appropriate strength with water or other suitable fluid prior to administration and that once opened any unused portion is to be discarded. The label states also the total osmolar concentration in mOsmol per L. Where the contents are less than 100 mL, or where the label states that the Injection is not for direct injection but is to be diluted before use, the label alternatively may state the total osmolar concentration in mOsmol per mL.
Identification—
It responds to the tests for
Sodium 
191
and for
Phosphate 191.
Other requirements—
It meets the requirements under
Injections 1.
Assay for monobasic sodium phosphate—
Transfer an accurately measured volume of Injection, equivalent to about 300 mg of anhydrous monobasic sodium phosphate, to a 100-mL beaker, and dilute with water to about 50 mL. Place the electrodes of a suitable pH meter in the solution, and titrate with 0.1 N sodium hydroxide VS to the inflection point to a pH of about 8.8. Each mL of 0.1 N sodium hydroxide is equivalent to 13.80 mg of NaH2PO4·H2O.
Assay for dibasic sodium phosphate—
Transfer an accurately measured volume of Injection, equivalent to about 300 mg of anhydrous dibasic sodium phosphate, to a 100-mL beaker, and dilute with water to about 50 mL. Place the electrodes of a suitable pH meter in the solution, and titrate with 0.1 N hydrochloric acid VS to the inflection point to a pH of about 4.0. Each mL of 0.1 N hydrochloric acid is equivalent to 26.81 mg of Na2HPO4·7H2O.
