1-O--d-Glucopyranosyl-d-mannitol dihydrate [64519-82-0].
» Isomalt contains not less than 98.0 percent and not more than 102.0 percent of a mixture of 6-O--d-glucopyranosyl-d-sorbitol (1,6-GPS) and 1-O--d-glucopyranosyl-d-mannitol (1,1-GPM), and neither of the two components is less than 3.0 percent of the mixture, calculated on the anhydrous basis.
Packaging and storage Preserve in well-closed containers. No storage requirements specified.
Labeling Label it to indicate the percentage content of 1,6-GPS and 1,1-GPM.
A: Thin-Layer Chromatographic Identification Test 201
Adsorbent: 0.25-mm layer of chromatographic silica gel mixture containing a fluorescent indicator having optimal intensity at 254 nm.
Test solution: 5000 µg per mL in water.
Application volume: 1 µL.
Developing solvent system: a mixture of ethyl acetate, pyridine, water, acetic acid, and propionic acid (50:50:10:5:5).
Procedure Separately apply 1 µL each of the Standard solution and the Test solution to the thin-layer chromatographic plate, and thoroughly dry the starting points in warm air. Develop over 10 cm using the Developing solvent system, dry the plate in a current of hot air, and dip for 3 seconds in a 1 g per L solution of sodium periodate. Dip the plate for 3 seconds in a mixture of dehydrated alcohol, sulfuric acid, acetic acid, and anisaldehyde (90:5:1:1). Dry the plate in a current of hot air until colored spots become visible. The background color may be brightened by exposure to warm steam. Examine in daylight. The chromatograms obtained from the Standard solution and the Test solution show principal spot(s) similar in position and color.
B: The retention times of the two principal peaks in the chromatogram of the Assay preparation correspond to those in the chromatogram of the Standard preparation, as obtained in the Assay.
Conductivity Dissolve 20 g in carbon dioxide-free water prepared from distilled water, and dilute with the same solvent to 100 mL. Using an appropriate conductivity meter that has been standardized with a potassium chloride conductivity calibration standard, measure the conductivity of the solution while gently stirring with a magnetic stirrer. The conductivity of the test solution is not more than 20 µS per cm.
Water, Method I 921: not more than 7% determined on 0.3 g. Use a mixture of anhydrous methanol and formamide (1:1) as solvent at 50 ± 5.
Heavy metals, Method I 231: 10 µg per g.
Reducing sugars Dissolve 3.3 g in 10 mL of Purified Water with the aid of gentle heat. Cool, and add 20 mL of cupric citrate TS and a few glass beads. Heat so that boiling begins after 4 minutes, and maintain boiling for 3 minutes. Cool rapidly, and add 40 mL of dilute acetic acid, 60 mL of water, and 20 mL of 0.025 M iodine VS. With continuous shaking, add 25 mL of a mixture of 6 mL of hydrochloric acid and 94 mL of water. When the precipitate has dissolved, titrate the excess iodine with 0.05 N sodium thiosulfate VS using 1 mL of starch TS, added towards the end of the titration as an indicator. Not less than 12.8 mL of 0.05 N sodium thiosulfate VS is required, corresponding to not more than 0.3% of reducing sugars, determined on the anhydrous basis, as glucose.
Limit of nickel [noteThe purity of the reagents and the water used must be suitable for trace analysis, and the reagents and water must be free of nickel.]
Nickel standard solution Transfer 1 mL of nickel standard solution TS into a 100-mL volumetric flask, add 1 mL of nitric acid, dilute with water to volume, and mix. This solution contains the equivalent of 0.1 µg of nickel per mL.
Test solution Accurately weigh about 8 g of Isomalt into a 50-mL volumetric flask, add 8 mL of water and 3 mL of 65% nitric acid solution, and incubate at 95 for 1 hour. Allow the solution to cool to room temperature, add another 3 mL of 65% nitric acid solution, and incubate at 95 until all brown vapors have dissipated (about 11.5 hours). Allow the solution to cool to room temperature, carefully add 3 mL of 30 percent hydrogen peroxide, and keep the solution at 95 until the evolution of gas has ceased (about 12 hours). Allow the solution to cool to room temperature. Repeat the procedure two more times, i.e., adding 30 percent hydrogen peroxide, heating to 95, and cooling to room temperature. Dilute the resulting solution with water to 50 mL.
Blank Prepare as directed for the Test solution, except to omit the addition of Isomalt.
Standard solutions Into seven identical 10-mL volumetric flasks, introduce respectively 0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mL of Nickel standard solution equivalent to 0, 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 µg of nickel. To each flask, add a 2.0-mL portion of the Test solution, and dilute with water to volume.
Blank solutions Prepare as directed for Standard solutions except to replace 2 mL of the Test solution with 2 mL of the Blank.
Procedure Concomitantly determine the absorbances of the Standard solutions and the Blank solutions at the wavelength of maximum absorbance at 232.0 nm, with a suitable atomic absorption spectrophotometer (see Spectrophotometry and Light-Scattering 851) equipped with a graphite furnace and a nickel hollow-cathode lamp. Record the average of the steady readings for each of the Standard solutions and the Blank solutions. Plot the absorbances of the Standard solutions versus the quantity of nickel, in µg, in the portion of Nickel standard solution added to each Standard solution flask. Extrapolate the line joining the points on the graph until it meets the concentration axis. The distance between this point and the intersection of the axes represents the amount of nickel (AT), in µg, present in the portion of Test solution that was added to each of the Standard solution flasks. Similarly, plot the absorbance of the Blank solutions versus the quantity of nickel, in µg, in the portion of Nickel standard solution added to each of the Blank solution flasks, to determine the quantity of nickel (AB) in the portion of Blank added to each of the Blank solution flasks. Calculate the quantity, in µg, of nickel in the portion of Isomalt taken by the formula:
25(AT AB)Not more than 1 µg per g, calculated on the anhydrous basis, is found.
Mobile phase Prepare as directed in the Assay.
Resolution solution Dissolve accurately weighed quantities of USP Isomalt RS, USP Mannitol RS, and USP Sorbitol RS, and dilute quantitatively, and stepwise if necessary, with water to obtain a solution having known concentrations of about 20 mg per mL, 0.1 mg per mL, and 0.1 mg per mL, respectively.
Standard solution Dissolve an accurately weighed quantity of USP Sorbitol RS and USP Mannitol RS in water, and dilute quantitatively, and stepwise if necessary, with water to obtain a solution having a known concentration of about 0.1 mg of each per mL.
Test solution Use the Assay preparation.
Chromatographic system (see Chromatography 621) Prepare as directed in the Assay. Chromatograph the Resolution solution, and record the peak responses as directed for Procedure: the typical retention time of 1,1-GPM is about 12.3 minutes; the relative retention times are about 1.2 for 1,6-GPS, about 1.6 for mannitol, about 2.0 for sorbitol, and 1.0 for 1,1-GPM; and the resolution, R, between 1,1-GPM and 1,6-GPS is not less than 2.0.
Procedure Separately inject equal volumes (about 20 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the percentage of mannitol or sorbitol in the portion of Isomalt taken by the formula:
5000C/W(rU / rS)in which C is the concentration, in mg per mL, of USP Mannitol RS or USP Sorbitol RS in the Standard solution; W is the weight, in mg, of Isomalt used to prepare the Test solution; and rU and rS are the individual peak responses of mannitol or sorbitol obtained from the Test solution and the Standard solution, respectively: not more than 0.5% of mannitol and not more than 0.5% of sorbitol is found. Calculate the percentage of any unknown impurity in the portion of Isomalt taken by the formula:
5000C/W(ri / rS)in which C is the concentration, in mg per mL, of USP Sorbitol RS in the Standard solution; W is the weight, in mg, of Isomalt used to prepare the Test solution; ri is the peak response of each unknown impurity; and rS is the peak response of sorbitol in the Standard solution: not more than 0.5% of any individual impurity is found; and not more than 2.0% of total impurities, including mannitol and sorbitol, is found. Disregard any impurity peak that is less than 0.1%.
Mobile phase Use degassed water.
Standard preparation Dissolve an accurately weighed quantity of USP Isomalt RS in water, and dilute quantitatively, and stepwise if necessary, with water to obtain a solution having a known concentration of about 20 mg per mL.
Assay preparation Transfer about 1000 mg of Isomalt, accurately weighed, to a 50-mL volumetric flask, dissolve in and dilute with water to volume, and mix.
Chromatographic system (see Chromatography 621) The liquid chromatograph is equipped with a refractive index detector maintained at a constant temperature, a 7.8-mm × 30-cm column that contains packing L19, and a 4.6-mm × 3-cm guard column that contains packing L19. The flow rate is about 0.5 mL per minute. The column temperature is maintained at 80 ± 1. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the relative retention times are about 1.2 for 1,6-GPS and 1.0 for 1,1-GPM; the resolution, R, between 1,1-GPM and 1,6-GPS is not less than 2.0; and the relative standard deviation for replicate injections is not more than 2.0%, determined from the 1,6-GPS and 1,1-GPM peak responses.
Procedure Separately inject equal volumes (about 20 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the 1,6-GPS and 1,1-GPM peaks. Calculate the quantity, in mg, of 1,6-GPS in the portion of Isomalt taken by the formula:
50C(rU / rS)in which C is the concentration, in mg per mL, of 1,6-GPS in the Standard preparation, with calculation based on the declared 1,6-GPS content of USP Isomalt RS; and rU and rS are the 1,6-GPS peak responses obtained from the Assay preparation and the Standard preparation, respectively. Similarly, calculate the quantity, in mg, of 1,1-GPM in the portion of Isomalt taken.
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USP32NF27 Page 1260Pharmacopeial Forum: Volume No. 32(4) Page 1154
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.