USP CALCIUM WITH VITAMIN D CHEWABLE GELS

DEFINITION

Calcium with Vitamin D Chewable Gels contain NLT 90.0% and NMT 125.0% of the labeled amount of calcium (Ca), derived from substances generally recognized as safe and furnishing in ionizable form, and NLT 90.0% and NMT 140.0% of the labeled amount of vitamin D as cholecalciferol (C27H44O). They contain no other vitamins or minerals for which nutritional value is claimed.

IDENTIFICATION

•A.The Sample solution presents characteristic absorption at the characteristic wavelength of calcium as obtained in Calcium, Method 1 for Strength or significant emission at the characteristic wavelength of calcium as obtained in Calcium, Method 2 for Strength.

•B.The retention time of the cholecalciferol peak of the Sample solution corresponds to that of the Standard solution, as obtained in the test for Vitamin D (Cholecalciferol), Method 1.

STRENGTH

[Note—In the following assays, where more than one assay method is given for an individual ingredient, the requirements may be met by following any one of the specified methods, with the method used being stated in the labeling only if Method 1 is not used. Use low-actinic glassware.]

•Calcium, Method 1

[Note—Concentrations of the Standard solutions and the Sample stock solution may be modified to fit the linear or working range of the instrument.]

Lanthanum oxide solution:23.45 g/L of lanthanium oxide in a mixture of hydrochloric acid and water (1:1)

Standard stock solution:100 µg/mL of calcium prepared as follows. Use a commercially available atomic absorption calcium standard solution. Pipet an appropriate amount of the calcium standard solution into a volumetric flask, and dilute with 5% nitric acid.

Standard solutions:0.5, 1.0, 2.0, 3.0, and 4.0 µg/mL of calcium prepared as follows. Pipet 0.5, 1.0, 2.0, 3.0, and 4.0 mL of the Standard stock solution into separate 100-mL volumetric flasks. To each flask add 5.0 mL of Lanthanum oxide solution and dilute with 5% nitric acid to volume.

Sample solution:About 0.2 μg/mL of calcium prepared as follows. Weigh 10–20 Chewable Gels and calculate the average weight per Chewable Gel. Immerse the Chewable Gels in liquid nitrogen in a cryogenic vessel for 10 min. Cool a blender jar by swirling liquid nitrogen for about 1 min and discard the contents. Add frozen Chewable Gels to the cooled blender jar and grind to a fine powder. Weigh 400 mg into a microwave reaction vessel. Add 8 mL of nitric acid, heat at 100° until the samples react violently, and then cool. Add 1 mL of hydrogen peroxide. Use either the microwave digestion system or multiwave microwave sample preparation system according to the instructions provided with the respective systems. After microwave digestion is complete, heat at 140° for 2 h to evaporate the acid. Rinse each vessel with water, transfer the washing solutions to a 50-mL volumetric flask, repeat the washing several times, combine the washing solutions in the 50-mL volumetric flask and dilute with water to volume. Mix well. Dilute quantitatively with 5% nitric acid, adding 5 mL of the Lanthanum oxide solution per 100 mL of the final volume.

Source from USP:https://online.uspnf.com/uspnf/document/2_GUID-8FD7FC15-94CE-4EB9-B334-BC02660B9CD5_10101_en-US

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