Propyl Gallate
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C10H12O5 212.20

Benzoic acid, 3,4,5-trihydroxy-, propyl ester.
Propyl gallate [121-79-9].
» Propyl Gallate contains not less than 98.0 percent and not more than 102.0 percent of C10H12O5, calculated on the dried basis.
Packaging and storage— Preserve in tight containers, protected from light, and avoid contact with metals.
Solution: 10 µg per mL.
Medium: methanol.
Melting range 741: between 146 and 150.
Loss on drying 731 Dry it at 105 for 4 hours: it loses not more than 0.5% of its weight.
Residue on ignition 281: not more than 0.1%.
Assay— Transfer about 100 mg of Propyl Gallate, accurately weighed, to a 250-mL volumetric flask, dissolve in about 100 mL of methanol, dilute with methanol to volume, and mix. Transfer 5.0 mL of this solution to a 200-mL volumetric flask, dilute with methanol to volume, and mix. Concomitantly determine the absorbances of this solution and a Standard solution of USP Propyl Gallate RS in methanol having a known concentration of about 10 µg per mL, in 1-cm cells at the wavelength of maximum absorbance at about 273 nm, with a suitable spectrophotometer, using methanol as the blank. Calculate the quantity, in mg, of C10H12O5 in the portion of Propyl Gallate taken by the formula:
10C(AU / AS)
in which C is the concentration, in µg per mL, of USP Propyl Gallate RS in the Standard solution, and AU and AS are the absorbances of the solution of Propyl Gallate and the Standard solution, respectively.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, B.A.
(EM105) Excipient Monographs 1
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 1324
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.