Alumina,Magnesia,and Simethicone Tablets
»Alumina,Magnesia,and Simethicone Tablets contain the equivalent of not less than 90.0percent and not more than 115.0percent of the labeled amounts of aluminum hydroxide [Al(OH)3]and magnesium hydroxide [Mg(OH)2],and an amount of polydimethylsiloxane [-(CH3)2SiO-]nthat is not less than 85.0percent and not more than 115.0percent of the labeled amount of simethicone.
Packaging and storage— Preserve in well-closed containers.
Labeling— Label the Tablets to indicate that they are to be chewed before being swallowed.Label the Tablets to state the sodium content if it is greater than 5mg per Tablet.The Tablets may be labeled to state the aluminum hydroxide content in terms of the equivalent amount of dried aluminum hydroxide gel,on the basis that each mg of dried gel is equivalent to 0.765mg of Al(OH)3.
Identification—
A: Infrared Absorption á197Sñ—
Cell: 0.5mm.
Solution: prepared as directed in the Assay for polydimethylsiloxane.
B: To a portion of finely powdered Tablets,equivalent to about 600mg of magnesium hydroxide,add 25mLof 3Nhydrochloric acid and 25mLof water,and mix.Boil gently for 2minutes.Allow to cool,and filter.Add 5drops of methyl red TS,heat to boiling,and add 6Nammonium hydroxide until the color of the solution just turns to deep yellow.Continue boiling for 2minutes,and filter:the filtrate so obtained responds to the tests for Magnesium á191ñ.
C: Wash the precipitate obtained in Identificationtest Bwith a hot solution of ammonium chloride (1in 50),and dissolve the precipitate in hydrochloric acid:the solution so obtained responds to Identificationtest Cunder Alumina,Magnesia,and Simethicone Oral Suspension.
Uniformity of dosage units á905ñ: meet the requirements for Weight Variationwith respect to aluminum hydroxide and to magnesium hydroxide.
Acid-neutralizing capacity á301ñ— The acid consumed by the minimum single dose recommended in the labeling is not less than 5mEq,and not less than the number of mEq calculated by the formula:
0.55(0.0385A)+0.8(0.0343M),
in which 0.0385and 0.0343are the theoretical acid-neutralizing capacities,in mEq,of Al(OH)3and Mg(OH)2,respectively,and AandMare the quantities,in mg,of Al(OH)3and Mg(OH)2in the specimen tested,based on the labeled quantities.
Defoaming activity—
Foaming solution— Dissolve 500µg of FD&C Blue No.1and 1g of octoxynol 9in 100mLof 0.1Nhydrochloric acid.
Procedure— [NOTE—For each test,employ a clean,unused,250-mLglass jar.]Transfer a quantity of finely powdered Tablets,passed completely through an 80-mesh sieve,equivalent to 20mg of simethicone,to a clean,unused,cylindrical 250-mLglass jar,fitted with a 50-mm cap,containing 100mLof Foaming solutionthat has been warmed to 37.Proceed as directed for Procedurein the test for Defoaming activityunder Simethicone,beginning with “Cap the jar.”The defoaming activity time does not exceed 45seconds.
Sodium content—
Potassium chloride solution,Sodium chloride stock solution,and Standard preparations— Prepare as directed in the test for Sodium contentunder Alumina,Magnesia,and Simethicone Oral Suspension.
Test preparation— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to the average weight of 1Tablet,to a 100-mLvolumetric flask.Add 50mLof 1Nhydrochloric acid,boil for 15minutes,cool to room temperature,dilute with water to volume,and mix.Filter,discarding the first few mLof the filtrate.Transfer 5.0mLof the filtrate to a 100-mLvolumetric flask containing 10.0mLof Potassium chloride solution,dilute with water to volume,and mix.
Procedure— Proceed as directed in the test for Sodium contentunder Alumina,Magnesia,and Simethicone Oral Suspension.Calculate the quantity,in mg,of sodium per Tablet taken by the formula:
2C.
Assay for aluminum hydroxide—
Edetate disodium titrant— Prepare and standardize as directed in the Assayunder Ammonium Alum.
Assay preparation— Weigh and finely powder not less than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 800mg of aluminum hydroxide,to a 150-mLbeaker,add 20mLof water,stir,and slowly add 30mLof 3Nhydrochloric acid.Heat gently,if necessary,to aid solution,cool to room temperature,and filter into a 200-mLvolumetric flask.Wash the filter with water into the flask,add water to volume,and mix.
Procedure— Proceed as directed for Procedurein the Assay for aluminum hydroxideunder Alumina,Magnesia,and Simethicone Oral Suspension.
Assay for magnesium hydroxide—
Assay preparation— Prepare as directed in the Assay for aluminum hydroxide.
Procedure— Proceed as directed for Procedurein the Assay for magnesium hydroxideunder Alumina,Magnesia,and Simethicone Oral Suspension.
Assay for polydimethylsiloxane— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 33mg of simethicone,to a suitable round,narrow-mouth,screw-capped,120-mLbottle,add 40mLof 0.1Nsodium hydroxide,and swirl to disperse.Add 20.0mLof toluene,close the bottle securely with a cap having an inert liner,and shake for 30minutes,accurately timed,on a reciprocating shaker (e.g.,about 200oscillations per minute and a stroke of 38±2mm).Transfer the mixture to a 125-mLseparator,and allow to separate.Remove the upper,organic layer to a screw-capped,centrifuge tube containing about 2g of anhydrous sodium sulfate.Close the tube with a screw-cap having an inert liner,agitate vigorously,and centrifuge the mixture until a clear supernatant (Assay preparation)is obtained.Similarly prepare a Standard preparation,using about 33mg of USP Polydimethylsiloxane RS,accurately weighed.Prepare a blank by mixing 10mLof toluene with about 1g of anhydrous sodium sulfate and centrifuging to obtain a clear supernatant.Concomitantly determine the absorbances of the solutions in 0.5-mm cells at the wavelength of maximum absorbance at about 7.9µm (1265.8cm-1),with a suitable IRspectrophotometer,using the blank to set the instrument.Calculate the quantity,in mg,of [-(CH3)2SiO-]nin the portion of Tablets taken by the formula:
(W)(AU/AS),
in which Wis the weight,in mg,of USP Polydimethylsiloxane RSused to prepare the Standard preparation;and AUand ASare the absorbances of the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Elena Gonikberg,Ph.D.,Scientist
Expert Committee:(PA4)Pharmaceutical Analysis 4
USP28–NF23Page 82
Pharmacopeial Forum:Volume No.29(6)Page 1842
Phone Number:1-301-816-8251