Calcium Glubionate Syrup
Calcium Glubionate Syrup is a solution containing equimolar amounts of Calcium Gluconate and Calcium Lactobionate or with Calcium Lactobionate predominating. It contains NLT 95.0% and NMT 105.0% of the labeled amount of calcium (Ca).
•  A. Identification Tests—General, Calcium 191
Sample solution:  Syrup in water (1 in 10)
Acceptance criteria:  Meets the requirements
•  B. Thin-Layer Chromatography
Standard solution:  2 mg/mL of calcium gluconate and 4 mg/mL of calcium lactobionate in water
Sample solution:  Equivalent to 0.4 mg/mL of calcium, from Syrup in water
Chromatographic system 
Adsorbent:  0.25-mm layer of chromatographic silica gel
Application volume:  5 µL
Developing solvent system:  Alcohol, ethyl acetate, ammonium hydroxide, and water (50:10:10:30)
Spray reagent:  Dissolve 2.5 g of ammonium molybdate in 50 mL of 2 N sulfuric acid in a 100-mL volumetric flask. Add 1.0 g of ceric sulfate, swirl to dissolve, and dilute with 2 N sulfuric acid to volume.
Samples:  Standard solution and Sample solution
Develop the chromatogram until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the chamber and dry at 100 for 20 min. Allow to cool, and spray with Spray reagent. Heat the plate at 110 for 10 min.
Acceptance criteria:  The two principal spots of the Sample solution correspond in color, size, and RF value to those obtained from the Standard solution. [Note—Sucrose, if present in the Sample solution, appears in the chromatogram as a spot between the two principal spots. ]
•  Procedure
Sample solution:  Transfer a portion of Syrup equivalent to 70 mg of Ca into a suitable beaker. Add 2 mL of 3 N hydrochloric acid, and dilute with water to 150 mL.
Analysis:  While stirring the Sample solution with a magnetic stirrer, add 20 mL of 0.05 M edetate disodium VS from a 50-mL buret. Add 15 mL of 1 N sodium hydroxide and 300 mg of hydroxy naphthol blue, and continue the titration to a blue endpoint. Each mL of 0.05 M edetate disodium is equivalent to 2.004 mg of calcium (Ca).
Acceptance criteria:  95.0%–105.0%
•  pH 791: 3.4–4.5
•  Packaging and Storage: Preserve in tight containers, at a temperature not exceeding 30, and avoid freezing.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Domenick Vicchio, Ph.D.
Senior Scientific Liaison
(SM42010) Monographs - Small Molecules 4
USP35–NF30 Page 2451
Pharmacopeial Forum: Volume No. 27(6) Page 3257