Propyl Gallate
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Benzoic acid,3,4,5-trihydroxy-,propyl ester.
Propyl gallate [121-79-9].
»Propyl Gallate contains not less than 98.0percent and not more than 102.0percent of C10H12O5,calculated on the dried basis.
Packaging and storage—
Preserve in tight containers,protected from light,and avoid contact with metals.
Identification—
Solution:
10µg per mL.
Medium:
methanol.
Loss on drying á731ñ—
Dry it at 105
for 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%.
Heavy metals,Method IIá231ñ:
0.001%.
Organic volatile impurities,Method Vá467ñ:
meets the requirements.
Solvent—
Use dimethyl sulfoxide.
Assay—
Transfer about 100mg of Propyl Gallate,accurately weighed,to a 250-mLvolumetric flask,dissolve in about 100mLof methanol,dilute with methanol to volume,and mix.Transfer 5.0mLof this solution to a 200-mLvolumetric flask,dilute with methanol to volume,and mix.Concomitantly determine the absorbances of this solution and a Standard solution of USP Propyl Gallate RSin methanol having a known concentration of about 10µg per mL,in 1-cm cells at the wavelength of maximum absorbance at about 273nm,with a suitable spectrophotometer,using methanol as the blank.Calculate the quantity,in mg,of C10H12O5in the portion of Propyl Gallate taken by the formula:
10C(AU/AS),
in which Cis the concentration,in µg per mL,of USP Propyl Gallate RSin the Standard solution,and AUand ASare the absorbances of the solution of Propyl Gallate and the Standard solution,respectively.
Auxiliary Information—
Staff Liaison:Catherine Sheehan,B.Sc.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3067
Phone Number:1-301-816-8262