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C6H6O3 126.11

3-Hydroxy-2-methyl-4-pyrone [118-71-8].
» Maltol contains not less than 99.0 percent of C6H6O3, calculated on the anhydrous basis.
Packaging and storage— Preserve in tight containers, protected from light. No storage requirements specified.
B: Ultraviolet Absorption 197U
Solution: 0.01 mg per mL.
Medium: 0.1 N hydrochloric acid.
Melting range, Class 1a 741: between 160 and 164.
Water, Method I 921: not more than 0.5%.
Residue on ignition 281: not more than 0.2%, determined on 1.0 g.
Lead 251: 10 µg per g.
Standard preparation— Dissolve an accurately weighed quantity of USP Maltol RS in 0.1 N hydrochloric acid, and dilute quantitatively, and stepwise if necessary, with 0.1 N hydrochloric acid to obtain a solution having a known concentration of about 0.01 mg per mL.
Assay preparation— Transfer about 50 mg of Maltol, accurately weighed, to a 250-mL volumetric flask, dissolve in and dilute with 0.1 N hydrochloric acid to volume, and mix. Pipet 5 mL of this solution into a 100-mL volumetric flask, dilute with 0.1 N hydrochloric acid to volume, and mix.
Procedure— With a suitable spectrophotometer, using 0.1 N hydrochloric acid as a blank, concomitantly determine the absorbances of the Standard preparation and the Assay preparation at the wavelength of maximum absorbance at about 274 nm. Calculate the quantity, in mg, of C6H6O3 in the portion of Maltol taken by the formula:
5000C(AU / AS)
in which C is the concentration, in mg per mL, of USP Maltol RS in the Standard preparation; and AU and AS are the absorbances obtained from the Assay preparation and the Standard preparation, 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 1278
Pharmacopeial Forum: Volume No. 31(5) Page 1425