Menadiol Sodium Diphosphate
1,4-Naphthalenediol,2-methyl-,bis(dihydrogen phosphate),tetrasodium salt,hexahydrate.
2-Methyl-1,4-naphthalenediol bis(dihydrogen phosphate)tetrasodium salt,hexahydrate [6700-42-1].
Anhydrous 422.09 [131-13-5].
»Menadiol Sodium Diphosphate contains not less than 97.5percent and not more than 102.0percent of C11H8Na4O8P2,calculated on the anhydrous basis.
Packaging and storage Preserve in tight,light-resistant containers,and store in a cold place.
A: Dissolve about 200mg of Menadiol Sodium Diphosphate in 10mLof water,add 10mLof 2Nsulfuric acid,10mLof 0.1Nceric sulfate,and 1mLof 30percent hydrogen peroxide previously diluted with 5mLof water,and extract the solution with two 10-mLportions of chloroform.Gently evaporate the clear chloroform solution on a steam bath to dryness,and dry the residue at 80for 1hour:the menadione so obtained melts between 104and 107.
B: To 50mg of the dried residue obtained in Identificationtest Aadd 5mLof water,then add 75mg of sodium bisulfite,and heat on a steam bath,shaking vigorously until the substance is dissolved and the solution is practically colorless.Dilute with water to 50mL,and mix.To 2mLof the solution add 2mLof alcoholic ammonia (prepared by mixing equal volumes of alcohol and ammonium hydroxide),shake,and add 3drops of ethyl cyanoacetate:a deep purplish blue color is produced,and on the addition of 1mLof sodium hydroxide solution (1in 3),it changes to green and then to yellow.
C: To about 20mg contained in a small beaker add 1mLof water,2drops of nitric acid,and 1mLof sulfuric acid,and heat slowly to the evolution of white fumes.Cool,cautiously dilute with water to about 10mL,and filter if not clear.Render the filtrate slightly alkaline to litmus with 6Nammonium hydroxide,then render it acid with nitric acid,and add to the warm solution 3mLof ammonium molybdate TS:a yellow precipitate is formed within a few minutes.
Water,Method Iá921ñ: between 19.0%and 21.5%.
Assay Dissolve about 100mg of Menadiol Sodium Diphosphate,accurately weighed,in 25mLof water,and add 25mLof glacial acetic acid and 25mLof 3Nhydrochloric acid.Titrate the solution with 0.02Nceric sulfate VS,determining the endpoint potentiometrically using a calomel-platinum electrode system.Each mLof 0.02Nceric sulfate is equivalent to 4.221mg of C11H8Na4O8P2.
Auxiliary Information Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28NF23Page 1203Pharmacopeial Forum:Volume No.29(5)Page 1531