Butamben, chemical structure, molecular formula, Reference Standards

Butamben

C11H15NO2 193.24

Benzoic acid,4-amino-,butyl ester.
Butyl p-aminobenzoate [94-25-7].

»Butamben,dried over phosphorus pentoxide for 3hours,contains not less than 98.0percent and not more than 101.0percent of C11H15NO2.

Packaging and storage— Preserve in well-closed containers.

USP Reference standards á11ñ— USP Butamben RS.

Completeness and color of solution— One g dissolves completely in 30mLof alcohol and in 30mLof ether,and the solutions are colorless.

Identification,Infrared Absorption á197Kñ.

Melting range,Class Iá741ñ: between 57

and 59

Reaction— Dissolve 1g in 10mLof neutralized alcohol:a clear solution results.Dilute this solution with 10mLof water,and add 2drops of phenolphthalein TSand 1drop of 0.1Nsodium hydroxide:a red color is produced.

Loss on drying á731ñ— Dry it over phosphorus pentoxide for 3hours:it loses not more than 1.0%of its weight.

Residue on ignition á281ñ: not more than 0.2%.

Chloride— To a solution of 200mg in 10mLof alcohol add 1mLof 2Nnitric acid and a few drops of silver nitrate TS:no opalescence is produced.

Heavy metals,Method Iá231ñ— Dissolve 2g in 2mLof 1Nacetic acid and sufficient alcohol to make 25mL:the limit is 0.001%.

Assay—

Ferrocyphen indicator solution— Dissolve,without warming,0.5g of ferrocyphen in 50mLof sulfuric acid.

Procedure— Dissolve about 400mg of Butamben,previously dried and accurately weighed,in a mixture of 100mLof water and 20mLof hydrochloric acid.Add 1mLof Ferrocyphen indicator solution.Cool the solution in an ice bath to about 10

,and titrate with 0.1Msodium nitrite VSto a violet endpoint that is stable for not less than three minutes.Perform a blank determination,and make any necessary correction.Each mLof 0.1Msodium nitrite is equivalent to 19.32mg of C11H15NO2.

Auxiliary Information— Staff Liaison:Karen A Russo,Ph.D.,Scientist

Expert Committee:(PA1)Pharmaceutical Analysis 1

USP28–NF23Page 309

Phone Number:1-301-816-8379