Calcium and Colecalciferol Tablets
Definition
Calcium and Colecalciferol Tablets contain Calcium Carbonate and Colecalciferol.
Content of calcium
85.0 to 115.0% of the stated amount.
Content of colecalciferol, C27H44O
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.
A peak in the chromatogram obtained with solution (1) has the same retention time as the peak due to colecalciferol 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 Colecalciferol comply with the requirements stated under Tablets, with respect to the content of Colecalciferol, 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 may be used.
Calculate the content of C27H44O in each tablet using the declared content of C27H44O in colecalciferol 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 to boil 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 colecalciferol
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 C27H44O in the tablets using the declared content of C27H44O in colecalciferol 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 Colecalciferol is equivalent to 40 IU of antirachitic activity (vitamin D).