Polacrilin Potassium
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2-Propenoic acid,2-methyl-,polymer with divinylbenzene,potassium salt.
Methacrylic acid polymer with divinylbenzene,potassium salt [39394-76-5].
»Polacrilin Potassium is the potassium salt of a unifunctional low-cross-linked carboxylic cation-exchange resin prepared from methacrylic acid and divinylbenzene.When previously dried at 105
for 6hours,it contains not less than 20.6percent and not more than 25.1percent of potassium.
for 6hours,it contains not less than 20.6percent and not more than 25.1percent of potassium.
Packaging and storage—
Preserve in well-closed containers.
Identification—
B:
Shake about 1g with 10mLof water:the aqueous phase does not respond to the tests for Potassium á191ñ.Shake about 1g with 10mLof 0.1Nhydrochloric acid:the aqueous phase responds to the tests for Potassium á191ñ.
Loss on drying á731ñ—
Dry it at 105for 6hours:it loses not more than 10.0%of its weight.
for 6hours:it loses not more than 10.0%of its weight.
Powder fineness á811ñ—
Transfer about 4g,accurately weighed,to a No.100standard sieve placed on top of a No.200standard sieve and pan.Using a soft 2-cm brush,brush the sample lightly across the No.100sieve until no more particles pass through.By brushing and tapping,dust off the particles on the underside of the No.100sieve into the No.200sieve.Obtain the weight of the material retained on the No.100sieve.Similarly,determine the weight of material retained by the No.200sieve;not more than 1.0%is retained on the No.100sieve,and not more than 30.0%is retained on the No.200sieve.
Iron á241ñ—
Transfer 0.10g to a suitable crucible,and ignite at a low heat until thoroughly ashed.Add to the carbonized mass 2mLof nitric acid and 5drops of sulfuric acid,and heat cautiously until white fumes are no longer evolved.Ignite,preferably in a muffle furnace,at 500to 600,until the carbon is completely burned off.Cool,add 4mLof 6Nhydrochloric acid,cover,digest on a steam bath for 15minutes,uncover,and slowly evaporate on a steam bath to dryness.Moisten the residue with 1drop of hydrochloric acid,add 10mLof hot water,and digest for 2minutes.Dilute with water to about 25mL.Filter,if necessary,rinse the crucible and the filter with 10mLof water,combining the filtrate and rinsing in a 50-mLcolor-comparison tube,add 2mLof hydrochloric acid,dilute with water to 45mL,and mix.The limit is 0.01%.
to 600,until the carbon is completely burned off.Cool,add 4mLof 6Nhydrochloric acid,cover,digest on a steam bath for 15minutes,uncover,and slowly evaporate on a steam bath to dryness.Moisten the residue with 1drop of hydrochloric acid,add 10mLof hot water,and digest for 2minutes.Dilute with water to about 25mL.Filter,if necessary,rinse the crucible and the filter with 10mLof water,combining the filtrate and rinsing in a 50-mLcolor-comparison tube,add 2mLof hydrochloric acid,dilute with water to 45mL,and mix.The limit is 0.01%.
Sodium—
Test solution—
Transfer about 2g,accurately weighed,to a 400-mLborosilicate beaker,add 20mLof sulfuric acid,cover with a borosilicate watch glass,and heat until charring is complete.While continuing to heat the beaker,add 20mLof nitric acid dropwise.Continue to heat and add nitric acid until all of the organic material has been destroyed as indicated by the contents of the beaker turning from brown to a very pale straw-colored or colorless solution.Continue to evaporate the solution,and if it turns brown during the evaporation,add nitric acid dropwise until the brown color disappears.Evaporate just to dryness,cool,and dissolve the residue in 40mLof water and 10mLof 6Nhydrochloric acid.Heat to boiling,cool,transfer to a 100-mLvolumetric flask,dilute with water to volume,and mix.
Procedure—
To three separate 100-mLvolumetric flasks add,respectively,1.00mL,2.00mL,and 3.00mLof a solution containing 254.2mg of sodium chloride in 1000mLof water.Add water to volume,and mix to obtain sodium chloride solutions having concentrations equivalent to 1µg of Na per mL,2µg of Na per mL,and 3µg of Na per mL,respectively.Adjust the settings of a suitable flame photometer so that the emission of the solution containing 3.00mLof the sodium chloride solution reads close to 100%at 589nm.Determine the readings of the three solutions at 589nm.Readjust the wavelength setting to 580nm,and determine the background emission reading for one of these standards.Pipet 5mLof the Test solutioninto a 100-mLvolumetric flask,add water to volume,and mix.Observe the emission reading of this solution at 589nm,using the same instrument settings,then readjust the wavelength setting to 580nm,and observe the background emission reading.Subtract the corresponding background readings from the standard and test specimen readings.Prepare a standard curve by plotting the corrected standard readings versus the square root of the sodium concentration.From this standard curve,determine the sodium content of the test specimen.It is not greater than 0.20%.
Heavy metals,Method IIIá231ñ:
0.002%.
Organic volatile impurities,Method IVá467ñ:
meets the requirements.
Assay for potassium—
Sodium stock solution—
Transfer 7.306g of sodium chloride,previously dried at 125for 30minutes and accurately weighed,to a 500-mLvolumetric flask,add water to volume,and mix.This solution contains 5.76g of Na per 1000mL.
for 30minutes and accurately weighed,to a 500-mLvolumetric flask,add water to volume,and mix.This solution contains 5.76g of Na per 1000mL.
Potassium stock solution—
Transfer 745.5mg of potassium chloride,previously dried at 125for 30minutes and accurately weighed,to a 1000-mLvolumetric flask,add water to volume,and mix.This solution contains 391mg of Kper 1000mL.
for 30minutes and accurately weighed,to a 1000-mLvolumetric flask,add water to volume,and mix.This solution contains 391mg of Kper 1000mL.
Surfactant solution—
Transfer 5.0g of a suitable nonionic surfactant to a 250-mLbeaker,add 200mLof water,and stir to dissolve.Transfer this solution to a 500-mLvolumetric flask,dilute with water to volume,and mix.[NOTE—To prevent foaming when using this solution,gently run the solution down the sides of the vessel,and use gentle action when mixing.]
Diluted sodium solution—
Transfer 50.0mLof Sodium stock solutionand 10.0mLof Surfactant solutionto a 100-mLvolumetric flask,dilute with water to volume,and mix gently to prevent foaming.
Standard preparations—
To three separate 500-mLvolumetric flasks transfer,respectively,3.0-,4.0-,and 5.0-mLportions of Potassium stock solutions.To each flask add 50.0mLof Sodium stock solutionand 10.0mLof Surfactant solution,dilute with water to volume,and mix gently to prevent foaming.Each mLof these solutions contains 2.346,3.128,and 3.910µg of K,respectively.
Assay preparation—
Transfer about 1.4g of Polacrilin Potassium,previously dried and accurately weighed,to a 50-mLsilica crucible,moisten with 4mLof sulfuric acid,heat over a small flame until the acid has fumed off,moisten the residue with a few drops of sulfuric acid,and ignite strongly.Allow to cool,transfer,with the aid of water,to a 1000-mLvolumetric flask,dilute with water to volume,and mix.Transfer 1.00mLof this solution to a 100-mLvolumetric flask,add 20.0mLof Diluted sodium solution,dilute with water to volume,and mix gently to prevent foaming.
Procedure—
Concomitantly determine the emittances of the Standard preparationsand the Assay preparationat 766nm,with a flame photometer,adjusting the instrument so that the most concentrated Standard preparationgives a reading near 100%.Prepare a standard curve by plotting the standard readings versus the square root of the potassium concentrations.From the curve,determine the concentration,CU,in µg per mL,of potassium in the Assay preparation.Calculate the weight,in mg,of potassium in the portion of Polacrilin Potassium taken by the formula:
100CU.
Auxiliary Information—
Staff Liaison:Karen A Russo,Ph.D.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3050
Phone Number:1-301-816-8379