Packaging and storage— Preserve in single-dose or multiple-dose containers,preferably of Type Iglass.

Labeling— The label states the total osmolar concentration in mOsmol per L.Where the contents are less than 100mL,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.

USP Reference standards á11ñ— USP Endotoxin RS.

Identification— It responds to the tests for Magnesium á191ñand for Sulfate á191ñ.

Bacterial endotoxins á85ñ— It contains not more than 0.09USP Endotoxin Unit per mg of magnesium sulfate.

pHá791ñ: between 5.5and 7.0,when diluted to a concentration of 5%(w/v).

Particulate matter á788ñ: meets the requirements for small-volume injections.

Other requirements— It meets the requirements under Injections á1ñ.

Assay— Transfer to a beaker an accurately measured volume of Injection,equivalent to about 250mg of anhydrous magnesium sulfate,and dilute with water to 100mL.Adjust the reaction of the solution to a pHof 7(using pHindicator paper;see Indicator and Test Papersunder Reagentsin the section Reagents,Indicators,and Solutions)with 1Nsodium hydroxide,add 5mLof ammonia–ammonium chloride buffer TSand 0.15mLof eriochrome black TS,and titrate with 0.05Medetate disodium VSto a blue endpoint.Each mLof 0.05Medetate disodium is equivalent to 12.32mg of MgSO4·7H2O.

Expert Committee:(PA3)Pharmaceutical Analysis 3

USP28–NF23Page 1175

Phone Number:1-301-816-8330