Aluminum Dichlorohydrex Propylene Glycol
Aly(OH)3y-zClz·nH2O·mC3H8O2

Aluminum chlorohydroxide propylene glycol complex.
Aluminum hydroxychloride propylene glycol complex.
»Aluminum Dichlorohydrex Propylene Glycol consists of aluminum dichlorohydrate in which some of the waters of hydration have been replaced by propylene glycol.It encompasses a range of aluminum-to-chloride atomic ratios between 0.90:1and 1.25:1.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of anhydrous aluminum dichlorohydrate.
Packaging and storage— Preserve in well-closed containers.
Labeling— The label states the content of anhydrous aluminum dichlorohydrate.
Identification—
A: Asolution (1in 10)responds to the tests for Aluminum á191ñand for Chloride á191ñ.
B: Dissolve 0.5g in about 40mLof water,and while mixing adjust with 2.5Nsodium hydroxide to a pHof 9.55±0.05.Filter the suspension of precipitate thus obtained.Evaporate about 15mLof the filtrate to about 1mLon a hot plate: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.
pHá791ñ: between 3.0and 5.0,in a solution [15in 100(w/w)].
Limit of iron— Using Aluminum Dichlorohydrex Propylene Glycol instead of Aluminum Chlorohydrate,proceed as directed in the test for Limit of ironunder Aluminum Chlorohydrate.The limit is 150µg per g.
Content of aluminum— Using Aluminum Dichlorohydrex Propylene Glycol instead of Aluminum Chlorohydrate,proceed as directed in the test for Content of aluminumunder Aluminum Chlorohydrate.Use the result obtained to calculate the Aluminum/chloride atomic ratio.
Content of chloride— Using Aluminum Dichlorohydrex Propylene Glycol instead of Aluminum Chlorohydrate,proceed as directed in the test for Content of chlorideunder Aluminum Chlorohydrate.Use the result obtained 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 0.90:1and 1.25:1.
Assay— Calculate the percentage of anhydrous aluminum dichlorohydrate in the Aluminum Dichlorohydrex Propylene Glycol 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-to-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 92
Phone Number:1-301-816-8389