Aluminum Acetate Topical Solution, chemical structure, molecular formula, Reference Standards

Aluminum Acetate Topical Solution

C6H9AlO6 204.11

Acetic acid,aluminum salt.
Aluminum acetate [139-12-8].

»Aluminum Acetate Topical Solution yields,from each 100mL,not less than 1.20g and not more than 1.45g of aluminum oxide (Al2O3),and not less than 4.24g and not more than 5.12g of acetic acid (C2H4O2),corresponding to not less than 4.8g and not more than 5.8g of aluminum acetate (C6H9AlO6).Aluminum Acetate Topical Solution may be stabilized by the addition of not more than 0.6percent of Boric Acid.

Aluminum Subacetate Topical Solution	545mL
Glacial Acetic Acid	15mL
Purified Water,a sufficient quantity, to make	1000mL

Add the Glacial Acetic Acid to the Aluminum Subacetate Topical Solution and sufficient water to make 1000mL.Mix,and filter,if necessary.

NOTE—Dispense only clear Aluminum Acetate Topical Solution.

Packaging and storage— Preserve in tight containers.

Identification— It responds to the tests for Aluminum á191ñand for Acetate á191ñ.

pHá791ñ: between 3.6and 4.4.

Limit of boric acid— Pipet 25mLinto 75mLof water in a conical flask.Add 3mLof phenolphthalein TS,then add 0.5Nsodium hydroxide VSfrom a buret until a faint pink color is obtained.Heat to boiling,and again neutralize.Add 150mLof glycerin to the neutralized solution,and titrate with 0.5Nsodium hydroxide VS.Perform a blank determination in a similar manner.From the volume of 0.5Nsodium hydroxide VSused after the addition of the glycerin,subtract the volume used in the blank.Each mLof 0.5Nsodium hydroxide is equivalent to 30.92mg of H3BO3.

Heavy metals á231ñ— Dilute 2mLof it with water to 25mL:the limit is 0.001%.

Assay for aluminum oxide—

Edetate disodium titrant— Prepare and standardize as directed in the Assayunder Ammonium Alum.

Procedure— Pipet 25mLof Topical Solution into a 250-mLvolumetric flask,add 5mLof hydrochloric acid,dilute with water to volume,and mix.Pipet 25mLof this solution into a 250-mLbeaker,and add,in the order named and with continuous stirring,25.0mLof Edetate disodium titrantand 20mLof acetic acid–ammonium acetate buffer TS,then heat the solution near the boiling point for 5minutes.Cool,and add 50mLof alcohol and 2mLof dithizone TS.Titrate the solution with 0.05Mzinc sulfate VSto a bright rose-pink color.Perform a blank determination,substituting water for the sample,and make any necessary correction.Each mLof 0.05MEdetate disodium titrantis equivalent to 2.549mg of Al2O3.

Assay for acetic acid— Pipet 20mLof Topical Solution into a Kjeldahl flask containing a mixture of 20mLof phosphoric acid and 150mLof water.Connect the flask to a condenser,the delivery tube from which dips beneath the surface of 50.0mLof 0.5Nsodium hydroxide VScontained in a receiving flask.Distill about 160mL,then remove the delivery tube from below the surface of the liquid,allow the distilling flask to cool,add 50mLof water,and distill an additional 40to 45mLinto the receiving flask.Add phenolphthalein TSto the distillate,and titrate the excess 0.5Nsodium hydroxide VSwith 0.5Nsulfuric acid VS.Each mLof 0.5Nsodium hydroxide is equivalent to 30.03mg of C2H4O2.

Auxiliary Information— Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist

Expert Committee:(PA7)Pharmaceutical Analysis 7

USP28–NF23Page 87

Phone Number:1-301-816-8394