Calcium and Ergocalciferol Tablets
Definition
Calcium and Ergocalciferol Tablets contain Calcium Lactate Pentahydrate, Calcium Phosphate and Ergocalciferol.
Content of calcium
85.0 to 115.0% of the stated amount.
Content of ergocalciferol, C28H44O
90.0 to 120.0% of the stated amount.
Identification
10 volumes of water and 90 volumes of methanol.
The test is not valid unless, in the chromatogram obtained with solution (2), the resolution factor between the two principal peaks is at least 1.4. If necessary, adjust the composition of the mobile phase to obtain the required resolution.
The chromatogram obtained with solution (1) shows a peak with the same retention time as the peak due to ergocalciferol in the chromatogram obtained with solution (3).
Tests
Uniformity of content
Tablets containing less than 2 mg and/or less than 2% w/w of Ergocalciferol comply with the requirements stated under Tablets, with respect to the content of Ergocalciferol, using the following method of analysis. Carry out the following procedure protected from light. Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
The chromatographic conditions described under Assay for ergocalciferol may be used.
Calculate the content of C28H44O in each tablet using the declared content of C28H44O in ergocalciferol BPCRS.
Assay
For calcium
Weigh and powder 20 tablets. To a quantity of the powder containing the equivalent of 50 mg of calcium add 50 mL of water and 5 mL of hydrochloric acid. Heat the dispersion gently to boiling and continue for about 2 minutes. Allow to cool and add 50 mL of 0.05m disodium edetate VS. Neutralise the solution using 2m sodium hydroxide, add 10 mL of ammonia buffer pH 10.9 and 50 mL of water. Titrate the excess of disodium edetate with 0.05m zinc chloride VS using mordant black II solution as indicator. Each mL of 0.05m disodium edetate VS is equivalent to 2.004 mg of Ca.
For ergocalciferol
Carry out the following procedure protected from light. Weigh and powder 20 tablets. Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
3 volumes of water and 97 volumes of methanol.
Calculate the content of C28H44O in the tablets using the declared content of C28H44O in ergocalciferol BPCRS.
Labelling
The label states (1) the equivalent number of IU (Units) of antirachitic activity (vitamin D); (2) the equivalent amount of calcium.
Each microgram of Ergocalciferol is equivalent to 40 IU of antirachitic activity (vitamin D).