Erythritol

C4H10O4

122.12

1,2,3,4-Butanetetrol.
Butane1,2,3,4-tetrol (meso-erythritol)

[149-32-6].

» Erythritol is obtained by fermentation of starch enzyme hydrolysate (from starches such as wheat and corn). It is obtained from the fermentation broth of suitable osmophilic yeasts such as Moniliella pollinis or Trichosporonoides megachiliensis. It contains not less than 96.0 percent and not more than 102.0 percent of C4H10O4, calculated on the anhydrous basis.

Packaging and storage— Preserve in well-closed containers. Store at room temperature.

USP Reference standards

—
USP Erythritol RS.

Identification—

A: Infrared Absorption

191K

B: Melting range

741

: between 119

and 123

Loss on drying

731

— Dry it at 105

for 4 hours; it loses not more than 0.2% of its weight. Use about 8 g of sample.

Water, Method I

921

: not more than 0.5%.

Conductivity— Dissolve 20.0 g of Erythritol in a 100-mL volumetric flask, and dilute with the same solvent to volume. Using an appropriate conductivity meter, choose a conductivity cell that is appropriate for the properties and conductivity of the solution to be examined. Use a certified reference material1 —for example, a solution of potassium chloride—that is appropriate for the measurement. The conductivity value of the certified reference material should be near the expected conductivity value of the solution to be examined. After calibrating the apparatus with a certified reference material solution, rinse the conductivity cell several times with water and at least twice with the aqueous solution to be examined. Measure the conductivity of the solution at a temperature of 20

while stirring gently with a magnetic stirrer: the conductivity is not more than 20 µS per cm.

Microbial enumeration tests

and Tests for specified microorganisms

— The total aerobic microbial count using the Plate Method is not more than 1000 cfu per g, and the total combined molds and yeasts count is not more than 100 cfu per g. It meets the requirements of the tests for absence of Salmonella species and Escherichia coli.

Residue on ignition

281

: not more than 0.1%.

Limit of lead—

Standard lead solution— Prepare as directed for Special Reagents under Heavy Metals

231

Test solution— Dissolve 20.0 g of Erythritol in diluted acetic acid, and dilute with diluted acetic acid to 100 mL. Add 2.0 mL of a saturated ammonium pyrrolidinedithiocarbamate solution (containing about 10 g of ammonium pyrrolidinedithiocarbamate per L) and 10.0 mL of methyl isobutyl ketone, and shake for 30 seconds. Protect from bright light. Allow the two layers to separate, and use the methyl isobutyl ketone layer.

Blank solution— Prepare as directed for Test solution, except to omit the use of Erythritol.

Standard solutions— Prepare as directed for Test solution, except to prepare three solutions by adding 0.5 mL, 1.0 mL, and 1.5 mL of Standard lead solution in addition to the 20.0 g of Erythritol.

Procedure— Set the atomic absorption spectrophotometer to zero, using methyl isobutyl ketone previously treated as described under Test solution, but without sample added. Use a lead hollow-cathode lamp as source of radiation, an air–acetylene flame, and an analysis wavelength of 283.3 nm. Introduce the Test solution and each of the three Standard solutions into the instrument. Record the steady absorbance reading. Plot the absorbance readings against the known concentrations of added lead (in µg), and draw a straight line. Extrapolate the line until it meets the concentration axis, which is equal to the concentration, in mg per kg, of lead in the sample. Not more than 0.5 mg per kg is found.

Related compounds—

Mobile phase, Assay preparation, Standard preparation, System suitability preparation, and Chromatographic system —Proceed as directed in the Assay.

Test solution— Use the Assay preparation.

Standard solution— Transfer 2.0 mL of the Standard preparation to a 100-mL volumetric flask, dilute with water to volume, and mix. This solution contains about 1 mg of erythritol per mL.

Procedure— Separately inject equal volumes (about 20 µL) of the Test solution and the Standard solution into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the percentage of each impurity found by the formula:

VC/W (ri / rS)

in which V is the volume, in mL, of the Test solution; C is the concentration, in mg per mL, of Erythritol in the Standard solution; W is the amount of Erythritol, in mg, taken to prepare the Test solution; ri is the peak response for the Test solution; and rS is the response of the erythritol peak in the Standard solution: not more than 2.0% of any individual impurity is found, and not more than 2.0% of total impurities is found.

Assay—

Mobile phase— Use filtered and degassed 0.01% sulfuric acid.

Standard preparation— Dissolve an accurately weighed quantity of USP Erythritol RS in water to obtain a solution having a known concentration of about 50 mg per mL.

Assay preparation— Transfer 500 mg of Erythritol, accurately weighed, to a 10-mL volumetric flask, dissolve in and dilute with water to volume, and mix.

System suitability preparation— Transfer accurately weighed amounts of USP Erythritol RS and glycerol to a suitable volumetric flask, and dissolve in and dilute with water to obtain a solution having concentrations of about 0.05 mg per mL each.

Chromatographic system (see Chromatography

621

)— The liquid chromatograph is equipped with a refractive index detector and a 7.8-mm × 30-cm column or equivalent that contains packing L17. The flow rate is about 0.8 mL per minute. The column temperature is maintained at 70

. Chromatograph the System suitability preparation, and record the peak responses as directed for Procedure: the relative retention times are about 1.0 for erythritol and 1.1 for glycerol; and the resolution, R, between erythritol and glycerol is not less than 2.0. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the relative standard deviation for replicate injections is not more than 2.0%.

Procedure— Separately inject equal volumes (about 10 µL) each of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms over a period of three times the retention time of erythritol, and measure the peak responses. Calculate the amount, in mg, of C4H10O4 in the portion of Erythritol taken by the formula:

VC(rU / rS)

in which V is the volume, in mL, of the Assay preparation; C is the concentration, in mg per mL, of USP Erythritol RS in the Standard preparation; and rU and rS are the peak responses for erythritol obtained from the Assay preparation and the Standard preparation, respectively.

1 Commercially available conductivity calibration solutions for conductivity meter standardization, standardized by methods traceable to the National Institute of Standards and Technology (NIST), may be used. Solutions prepared according to instructions given in the American Society for Testing and Materials (ASTM) Standard D1125 may be used, provided that the conductivity of the resultant solution is the same as that of the solution prepared from the NIST-certified material.

Auxiliary Information— Please check for your question in the FAQs before contacting USP.

Topic/Question	Contact	Expert Committee
Monograph	Robert H. Lafaver, B.A. Scientist 1-301-816-8335	(EM105) Excipient Monographs 1
Reference Standards	Lili Wang, Technical Services Scientist 1-301-816-8129 RSTech@usp.org
61	Radhakrishna S Tirumalai, Ph.D. Senior Scientist 1-301-816-8339	(MSA05) Microbiology and Sterility Assurance
62	Radhakrishna S Tirumalai, Ph.D. Senior Scientist 1-301-816-8339	(MSA05) Microbiology and Sterility Assurance

USP32–NF27 Page 1231

Pharmacopeial Forum: Volume No. 31(5) Page 1422

Chromatographic Column—

ERYTHRITOL

Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.