U.S. PHARMACOPEIA

Search USP29  
Aluminum Sesquichlorohydrex Propylene Glycol
Aly(OH)3y-zClz·nH2O·mC3H8O2

Aluminum chlorohydroxide propylene glycol complex.
Aluminum hydroxychloride propylene glycol complex.
» Aluminum Sesquichlorohydrex Propylene Glycol consists of aluminum sesquichlorohydrate in which some of the waters of hydration have been replaced by propylene glycol.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 1.26:1 and 1.90:1. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of anhydrous aluminum sesquichlorohydrate.
Packaging and storage— Preserve in well-closed containers.
Labeling— The label states the content of anhydrous aluminum sesquichlorohydrate.
Identification—
A: A solution (1 in 10) responds to the tests for Aluminum 191 and for Chloride 191.
Test specimen— Dissolve 0.5 g in about 40 mL of water, and while mixing adjust with 2.5 N sodium hydroxide to a pH of 9.55 ± 0.05. Filter the suspension of precipitate thus obtained. Evaporate about 15 mL of the filtrate to about 1 mL on a hot plate. Deposit this solution on a silver chloride disk.
Standard specimen: a similar preparation of propylene glycol.
pH 791: between 3.0 and 5.0, in a solution [15 in 100 (w/w)].
Arsenic, Method I 211: 2 µg per g.
Limit of iron— Using Aluminum Sesquichlorohydrex Propylene Glycol instead of Aluminum Chlorohydrate, proceed as directed in the test for Limit of iron under Aluminum Chlorohydrate. The limit is 150 µg per g.
Content of aluminum— Using Aluminum Sesquichlorohydrex Propylene Glycol instead of Aluminum Chlorohydrate, proceed as directed in the test for Content of aluminum under Aluminum Chlorohydrate. Use the result obtained to calculate the Aluminum/chloride atomic ratio.
Content of chloride— Using Aluminum Sesquichlorohydrex Propylene Glycol instead of Aluminum Chlorohydrate, proceed as directed in the test for Content of chloride under 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 aluminum by the percentage of chloride found in the test for Content of chloride, and multiply by 35.453/26.98, in which 35.453 and 26.98 are the atomic weights of chlorine and aluminum, respectively: the ratio is between 1.26:1 and 1.90:1.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay— Calculate the percentage of anhydrous aluminum sesquichlorohydrate in the Aluminum Sesquichlorohydrex Propylene Glycol by the formula:
Al({26.98x + [17.01(3x 1)] + 35.453} / 26.98x),
in which Al is the percentage of aluminum found in the test for Content of aluminum, x is the aluminum/chloride atomic ratio found in the test for Aluminum/chloride atomic ratio, 26.98 is the atomic weight of aluminum, 17.01 is the molecular weight of the hydroxide anion (OH), and 35.453 is the atomic weight of chlorine (Cl).
Auxiliary Information— Staff Liaison : Feiwen Mao, M.S., Senior Scientific Associate
Expert Committee : (MDOOD05) Monograph Development-Ophthalmics Oncologics and Dermatologicals
USP29–NF24 Page 105
Phone Number : 1-301-816-8320