- British Pharmacopoeia Volume III
- Formulated Preparations: Specific Monographs
Colecalciferol Tablets |
Vitamin D analogue (Vitamin D3).
Colecalciferol Tablets contain Colecalciferol.
The tablets comply with the requirements stated under Tablets and with the following requirements.
90.0 to 125.0% of the stated amount.
A. In the test for Uniformity of content, the chromatogram obtained with solution (1) shows a peak with the same retention time as the principal peak in the chromatogram obtained with solution (2).
B. Extract one tablet, in powder, with 5 mL of ethanol-free chloroform, filter and to 1 mL of the filtrate add 9 mL of antimony trichloride solution. A brownish red colour is produced.
Tablets containing less than 2 mg and/or less than 2% w/w of Colecalciferol comply with the requirements stated under Tablets using the following method of analysis. Carry out the following procedure in subdued light. Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
(1) For tablets containing more than 0.25 mg prepare the solution in the following manner. Add 4 mL of water to one tablet in an amber flask and disperse with the aid of ultrasound. Add 12 mL of dimethyl sulfoxide, mix, extract with 100 mL of hexane by shaking for 30 minutes, centrifuge the hexane layer and use the clear supernatant liquid. For tablets containing 0.25 mg or less carry out the same procedure but using 2 mL of water, 6 mL of dimethyl sulfoxide and 25 mL of hexane.
(2) 0.001% w/v of colecalciferol BPCRS in hexane.
(3) Dissolve 0.5 g of colecalciferol for performance test EPCRS in 2 mL of toluene and dilute to 10 mL with the mobile phase; heat under a reflux condenser in a water bath at 90° for 45 minutes and cool.
(a) Use a stainless steel column (20 cm × 4.6 mm) packed with silica gel for chromatography (5 µm) (Partisil is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 2 mL per minute.
(d) Use an ambient column temperature.
(e) Use a detection wavelength of 254 nm.
(f) Inject 20 µL of each solution.
8 volumes of pentan-1-ol and 992 volumes of hexane.
When the chromatogram is recorded under the prescribed conditions, approximate retention times relative to colecalciferol are 0.4 for precolecalciferol and 0.5 for trans-colecalciferol.
The test is not valid unless, in the chromatogram obtained with solution (3), the resolution factor between the peaks corresponding to precolecalciferol and trans-colecalciferol is at least 1.0. If necessary, adjust the proportions of the constituents and the flow rate of the mobile phase to obtain this resolution.
Calculate the content of colecalciferol, C27H44O, in each tablet using the declared content of C27H44O in colecalciferol BPCRS.
Carry out the following procedure in subdued light. Weigh and powder 25 tablets, or more if necessary. To a quantity of the powder containing 6 mg of colecalciferol add 50 mL of ethanol (96%), 14 mL of glycerol and 20 mL of a 50% w/v solution of potassium hydroxide. Boil under a reflux condenser for 30 minutes, swirling occasionally, add 110 mL of water and allow to stand for 10 minutes with occasional stirring. Cool and add sufficient ethanol (96%) to produce 250 mL. Shake 5 mL with 25 mL of petroleum spirit (boiling range, 40° to 60°) for 3 minutes and evaporate duplicate 5 mL portions of the extract to dryness in a current of oxygen-free nitrogen. Dissolve each residue in 1 mL of ethanol-free chloroform, add rapidly 9 mL of antimony trichloride solution and measure the absorbance of each solution at 500 nm and at 550 nm, 90 to 120 seconds after adding the reagent, Appendix II B. Repeat the operation using duplicate 1 mL portions of a solution containing a known amount of colecalciferol BPCRS in ethanol-free chloroform and beginning at the words 'add rapidly 9 mL of antimony trichloride solution …'. Subtract the absorbance at 550 nm from that at 500 nm and calculate the content of colecalciferol in mg from the average value so obtained and from the amount of colecalciferol in the reference solution using the declared content of C27H44O in colecalciferol BPCRS.
The label states the equivalent number of IU (units) of antirachitic activity (vitamin D) per tablet.
Each µg of Colecalciferol is equivalent to 40 IU of antirachitic activity (vitamin D).
When calciferol tablets are prescribed or demanded, Colecalciferol Tablets or Ergocalciferol Tablets shall be dispensed or supplied.