Aluminum Sesquichlorohydrate Solution
»Aluminum Sesquichlorohydrate Solution consists of complex basic aluminum chloride that is polymeric and encompasses a range of aluminum-to-chloride atomic ratios between 1.26:1and 1.90:1.The following solvents may be used:water,propylene glycol,dipropylene glycol,or alcohol.It contains the equivalent of not less than 90.0percent and not more than 110.0percent of the labeled concentration of anhydrous aluminum sesquichlorohydrate.
Packaging and storage— Preserve in well-closed containers.
Labeling— Label Solution to state the solvent used and the claimed concentration of anhydrous aluminum sesquichlorohydrate contained therein.
Identification—
A: Asolution containing the equivalent of about 100mg of anhydrous aluminum sesquichlorohydrate per mLresponds to the tests for Aluminum á191ñand for Chloride á191ñ.
B: Identification of propylene glycol(where stated on the label)—Add about 10mLof isopropyl alcohol to 2g of Solution,mix,and filter.Evaporate the filtrate to about 1mLon a steam bath:the IRabsorption spectrum of a film of this solution on a silver chloride disk exhibits maxima only at the same wavelengths as that of a similar preparation of a film of propylene glycol.
C: Identification of dipropylene glycol(where stated on the label)—Add about 10mLof isopropyl alcohol to 2g of Solution,mix,and filter.Evaporate the filtrate to about 1mLon a steam bath:the IRabsorption spectrum of a film of this solution on a silver chloride disk exhibits maxima only at the same wavelengths as that of a similar preparation of a film of dipropylene glycol.
D: Identification of alcohol(where stated on the label)—Mix 5drops of Solution in a small beaker with 1mLof potassium permanganate solution (1in 100)and 5drops of 2Nsulfuric acid,and cover the beaker immediately with filter paper moistened with a freshly prepared solution of 0.1g of sodium nitroferricyanide and 0.25g of piperazine in 5mLof water:an intense blue color is produced on the filter paper,the color becoming paler after a few minutes.
pHá791ñ: between 3.0and 5.0,in a solution prepared by diluting 3g of the Solution with water to obtain 10mL.
Arsenic,Method Iá211ñ— Prepare the Test Preparationusing an accurately weighed quantity of the Solution.The limit is 2µg per g.
Heavy metals,Method Iá231ñ— Prepare the Test Preparationusing an accurately weighed quantity of the Solution.The limit is 10µg per g.
Limit of iron— Using Aluminum Sesquichlorohydrate Solution instead of Aluminum Chlorohydrate Solution,proceed as directed in the test for the Limit of ironunder Aluminum Chlorohydrate Solution.The limit is 75µg per g.
Content of aluminum— Using Aluminum Sesquichlorohydrate Solution instead of Aluminum Chlorohydrate Solution,proceed as directed in the test for the Content of aluminumunder Aluminum Chlorohydrate Solution.Use the result to calculate the Aluminum/chloride atomic ratio.
Content of chloride— Using Aluminum Sesquichlorohydrate Solution instead of Aluminum Chlorohydrate Solution,proceed as directed in the test for the Content of chlorideunder Aluminum Chlorohydrate Solution.Use the result to calculate the Aluminum/chloride atomic ratio.
Aluminum/chloride atomic ratio— Divide the percentage of aluminum found in the test for Content of aluminumby the percentage of chloride found in the test for Content of chloride,and multiply by 35.453/26.98,in which 35.453and 26.98are the atomic weights of chlorine and aluminum,respectively:the ratio is between 1.26:1and 1.90:1.
Assay— Calculate the percentage of anhydrous aluminum sesquichlorohydrate in the Solution by the formula:
Al({26.98x +[17.01(3x -1)]+35.453}/26.98x),
in which Alis the percentage of aluminum found in the test for Content of aluminum,xis the aluminum/chloride atomic ratio found in the test for Aluminum/chloride atomic ratio,26.98is the atomic weight of aluminum,17.01is the molecular weight of the hydroxide anion (OH),and 35.453is the atomic weight of chlorine (Cl).
Auxiliary Information— Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(PA6)Pharmaceutical Analysis 6
USP28–NF23Page 95
Phone Number:1-301-816-8389