Calcium with Vitamin D Tablets
DEFINITION
Calcium with Vitamin D Tablets contain NLT 90.0% and NMT 125.0% of the labeled amount of calcium (Ca), derived from substances generally recognized as safe, and NLT 90.0% and NMT 165.0% of the labeled amount of Vitamin D, as cholecalciferol (C27H44O) or ergocalciferol (C28H44O). They contain no other vitamins or minerals for which nutritional value is claimed. They may contain other labeled added substances or additional ingredients in amounts that are unobjectionable.
STRENGTH
• Calcium
[Note—A commercially available atomic absorption standard solution for calcium may be used where preparation of a Calcium standard stock solution is described in the following assay. Concentrations of the Standard solutions and the Sample stock solution may be modified to fit the linear or working range of the instrument. ]
Lanthanum chloride solution:
Dissolve 26.7 g of lanthanum chloride in 0.125 N hydrochloric acid to make 100 mL.
Calcium standard stock solution:
Weigh 1.001 g of calcium carbonate, previously dried at 300
for 3 h and cooled in a desiccator for 2 h, and dissolve in 25 mL of 1 N hydrochloric acid. Boil to expel carbon dioxide, and dilute with water to 1000 mL to obtain a solution having a concentration of 400 µg/mL of calcium.
for 3 h and cooled in a desiccator for 2 h, and dissolve in 25 mL of 1 N hydrochloric acid. Boil to expel carbon dioxide, and dilute with water to 1000 mL to obtain a solution having a concentration of 400 µg/mL of calcium.
Standard stock solution:
100 µg/mL of calcium from a volume of Calcium standard stock solution in 0.125 N hydrochloric acid
Standard solutions:
Into separate 100-mL volumetric flasks, separately pipet 1.0, 1.5, 2.0, 2.5, and 3.0 mL of the Standard stock solution. To each flask add 1.0 mL of Lanthanum chloride solution, dilute with water to volume, and obtain Standard solutions having concentrations of 1.0, 1.5, 2.0, 2.5, and 3.0 µg/mL, of calcium.
Sample stock solution:
Weigh and finely powder NLT 20 Tablets. Transfer the equivalent to 500 mg of calcium, in 25 mL of concentrated hydrochloric acid, and heat for 30 min on a steam bath. Cool, dilute with water to 1000 mL, and filter.
Sample solution:
Quantitatively dilute a volume of Sample stock solution with 0.125 N hydrochloric acid to obtain a concentration of 100 µg/mL of calcium. Transfer 2.0 mL of this solution to a 100-mL volumetric flask, add 1.0 mL of Lanthanum chloride solution, and dilute with water to volume.
Spectrometric conditions
Mode:
Atomic absorption spectrophotometer
Lamp:
Calcium hollow-cathode
Flame:
Nitrous oxide–acetylene
Analytical wavelength:
Calcium emission line, 422.7 nm
Blank:
1 mL of Lanthanum chloride solution per 100 mL of 0.125 N hydrochloric acid
Analysis
Samples:
Standard solutions and Sample solution
Determine the absorbances of the solutions, against the Blank. Plot the absorbances of the Standard solutions versus the concentration, in µg/mL, of calcium, and draw the straight line best fitting the five plotted points. From the graph so obtained, determine the concentration, C, in µg/mL, of calcium in the Sample solution.
Calculate the percentage of the labeled amount of calcium (Ca) in the portion of Tablets taken:
Result = (C/CU) × 100
| C | = | = measured concentration of calcium in the Sample solution (µg/mL) |
| CU | = | = nominal concentration of calcium in the Sample solution (µg/mL) |
Acceptance criteria:
90.0%–125.0% of the labeled amount of calcium (Ca)
• Cholecalciferol or Ergocalciferol (Vitamin D)
[Note—Use low-actinic glassware throughout this procedure. ]
Mobile phase:
n-Hexane and isopropyl alcohol (99:1)
Standard solution:
2 µg/mL of USP Ergocalciferol RS or USP Cholecalciferol RS in n-hexane
System suitability solution:
Heat a volume of Standard solution at 60 for 1 h to partially isomerize vitamin D (ergocalciferol or cholecalciferol) to its corresponding precursor.
for 1 h to partially isomerize vitamin D (ergocalciferol or cholecalciferol) to its corresponding precursor.
Sample solution:
Weigh, and grind NLT 20 Tablets. Transfer the equivalent to 20 µg of cholecalciferol or ergocalciferol to a container having a polytef-lined screw cap. Add 8 mL of dimethyl sulfoxide and 12 mL of n-hexane, and shake for 45 min on a wrist-action shaker with tubes in a water bath maintained at 60. Centrifuge for 10 min, withdraw the hexane layer by means of a pipet, and transfer to an evaporation flask. Add 12 mL of n-hexane to the dimethyl sulfoxide layer, mix on a vortex mixer for 5 min, and again withdraw the hexane layer by means of a pipet, and add to the evaporation flask. Repeat this extraction with three additional 12-mL portions of n-hexane, adding the hexane extracts to the evaporation flask. Evaporate the combined hexane extracts in vacuum at room temperature to dryness. Dissolve in and dilute the residue in a volume of n-hexane to obtain a concentration of 2 µg/mL.
. Centrifuge for 10 min, withdraw the hexane layer by means of a pipet, and transfer to an evaporation flask. Add 12 mL of n-hexane to the dimethyl sulfoxide layer, mix on a vortex mixer for 5 min, and again withdraw the hexane layer by means of a pipet, and add to the evaporation flask. Repeat this extraction with three additional 12-mL portions of n-hexane, adding the hexane extracts to the evaporation flask. Evaporate the combined hexane extracts in vacuum at room temperature to dryness. Dissolve in and dilute the residue in a volume of n-hexane to obtain a concentration of 2 µg/mL.
Chromatographic system
Mode:
LC
Detector:
UV 265 nm
Column:
4.6-mm × 15-cm; 3-µm packing L8
Flow rate:
1 mL/min
Injection size:
100 µL
System suitability
Samples:
Standard solution and System suitability solution
Suitability requirements
Resolution:
NLT 10 between the vitamin D form present and its corresponding precursor, System suitability solution
Relative standard deviation:
NMT 3.0%, Standard solution
Analysis
Samples:
Standard solution and Sample solution
Measure the peak areas for vitamin D. Calculate the percentage of the labeled amount of cholecalciferol (C27H44O) or ergocalciferol (C28H44O) in the portion of Tablets taken:
Result = (rU/rS) × (CS/CU) × F × 100
| rU | = | = peak area of cholecalciferol or ergocalciferol from the Sample solution |
| rS | = | = peak area of cholecalciferol or ergocalciferol from the Standard solution |
| CS | = | = concentration of USP Cholecalciferol RS or USP Ergocalciferol RS in the Standard solution (µg/mL) |
| CU | = | = nominal concentration of cholecalciferol or ergocalciferol in the Sample solution (µg/mL) |
| F | = | = correction factor to account for the average amount of previtamin D present in the Sample solution, 1.09 |
Acceptance criteria:
90.0%–165.0% of the labeled amount of vitamin D as cholecalciferol (C27H44O) or ergocalciferol (C28H44O)
PERFORMANCE TESTS
• Disintegration and Dissolution of Dietary Supplements 
2040
:
Meet the requirements for Dissolution with respect to calcium
2040:
Meet the requirements for Dissolution with respect to calcium
Medium:
0.1 N hydrochloric acid; 900 mL
Apparatus 2:
75 rpm
Time:
30 min
Analysis:
Determine the amount of calcium (Ca) dissolved, using the procedure in Calcium, making any necessary volumetric adjustments.
Tolerances:
NLT 75% of the labeled amount of Ca is dissolved.
• Weight Variation of Dietary Supplements 2091:
Meet the requirements
2091:
Meet the requirements
CONTAMINANTS
• Microbial Enumeration Tests 2021:
The total aerobic microbial count does not exceed 3000 cfu/g, and the total combined molds and yeasts count does not exceed 300 cfu/g.
2021:
The total aerobic microbial count does not exceed 3000 cfu/g, and the total combined molds and yeasts count does not exceed 300 cfu/g.
• Microbiological Procedures for Absence of Specified Microorganisms 2022:
Meet the requirements of the tests for absence of Salmonella species, Escherichia coli, and Staphylococcus aureus
2022:
Meet the requirements of the tests for absence of Salmonella species, Escherichia coli, and Staphylococcus aureus
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in tight, light-resistant containers.
• Labeling:
The label states that the product is Calcium with Vitamin D Tablets. The label states also the quantities of calcium and Vitamin D in terms of metric units/Tablet, and the salt form of calcium and the chemical form of Vitamin D present in the Tablet.
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Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Natalia Davydova
Scientific Liaison 1-301-816-8328 |
(DS2010) Monographs - Dietary Supplements |
| 2021 |
Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison 1-301-816-8339 |
(GCM2010) General Chapters - Microbiology |
| 2022 |
Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison 1-301-816-8339 |
(GCM2010) General Chapters - Microbiology |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 1220
Pharmacopeial Forum: Volume No. 35(6) Page 1486