Panthenol
;)
Butanamide,2,4-dihydroxy-N-(3-hydroxypropyl)-3,3-dimethyl-,(±)-.
(±)-2,4-Dihydroxy-N-(3-hydroxypropyl)-3,3-dimethylbutyramide.
(±)-Pantothenyl alcohol [16485-10-2].
»Panthenol is a racemic mixture of the dextrorotatory and levorotatory isomers of panthenol.It contains not less than 99.0percent and not more than 102.0percent of C9H19NO4,calculated on the dried basis.
Packaging and storage—
Preserve in tight containers.
Identification—
A:
Infrared Absorption á197Mñ.
B:
To 1mLof a solution (1in 10)add 5mLof 1Nsodium hydroxide and 1drop of cupric sulfate TS,and shake vigorously:a deep blue color develops.
C:
To 1mLof a solution (1in 100)add 1mLof 1Nhydrochloric acid,and heat on a steam bath for about 30minutes.Cool,add 100mg of hydroxylamine hydrochloride,mix,and add 5mLof 1Nsodium hydroxide.Allow to stand for 5minutes,then adjust with 1Nhydrochloric acid to a pHof between 2.5and 3.0,and add 1drop of ferric chloride TS:a purplish-red color develops.
Specific rotation á781Sñ:
between -0.05
and +0.05.
and +0.05.
Test solution:
50mg per mL,in water.
Loss on drying á731ñ—
Dry it in vacuum over phosphorus pentoxide at 56for 4hours:it loses not more than 0.5%of its weight.
for 4hours:it loses not more than 0.5%of its weight.
Residue on ignition á281ñ:
not more than 0.1%.
Limit of aminopropanol—
Transfer about 10g,accurately weighed,to a 50-mLflask,and dissolve in 25mLof water.Add bromothymol blue TS,and titrate with 0.01Nsulfuric acid VSto a yellow endpoint.Each mLof 0.01Nsulfuric acid is equivalent to 750µg of aminopropanol.Not more than 0.10%is found.
Organic volatile impurities,Method Iá467ñ:
meets the requirements.
Assay—
Potassium biphthalate solution—
Dissolve 20.42g of potassium biphthalate in glacial acetic acid contained in a 1000-mLvolumetric flask.If necessary,warm the mixture on a steam bath to achieve complete solution,observing precautions against absorption of moisture.Cool to room temperature,dilute with glacial acetic acid to volume,and mix.
Procedure—
Transfer about 400mg of Panthenol,accurately weighed,to a 300-mLflask fitted to a reflux condenser by means of a standard-taper glass joint,add 50.0mLof 0.1Nperchloric acid VS,and reflux for 5hours.Cool,observing precautions to prevent atmospheric moisture from entering the condenser,and rinse the condenser with glacial acetic acid,collecting the rinsings in the flask.Add 5drops of crystal violet TS,and titrate with Potassium biphthalate solutionto a blue-green endpoint.Perform a blank determination,and note the difference in volumes required.Each mLof the difference in volumes of 0.1Nperchloric acid consumed is equivalent to 20.53mg of C9H19NO4.
Auxiliary Information—
Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(DSN)Dietary Supplements:Non-Botanicals
USP28–NF23Page 1464
Phone Number:1-301-816-8389