Action and use
Vitamin B12 analogue.
Definition
Cyanocobalamin Tablets contain Cyanocobalamin. They are coated.
The tablets comply with the requirements stated under Tablets and with the following requirements.
Content of cyanocobalamin, C63H88CoN14O14P
90.0 to 115.0% of the stated amount.
Identification
A. In the test for Uniformity of content, the principal peak in 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. Gently shake 10 tablets with 20 mL of
chloroform to remove the coating and dry the tablet cores in a current of air. Transfer to a clean flask and powder with the aid of a glass rod. To a quantity of the powdered tablet cores containing 0.2 mg of cyanocobalamin, add 10 mL of a mixture of 1 volume of
2-ethoxyethanol and 3 volumes of
water, shake vigorously for 5 minutes, centrifuge at 3000 revolutions per minute for 15 minutes and filter using a filter with a pore size of 0.45 µm. The
light absorption of the filtrate,
Appendix II B, in the range 345 to 560 nm exhibits maxima at about 361 nm and 550 nm. No maximum is exhibited at 351 nm (distinction from hydroxocobalamin).
Tests
Uniformity of content
Tablets containing less than 2 mg and/or less than 2% w/w of Cyanocobalamin comply with the requirements stated under Tablets using the following method of analysis. Carry out the procedure protected from light. Carry out the method for liquid chromatography, Appendix III D, using the following solutions in water.
(1) Shake one tablet with 6 mL of
water for 5 minutes, dilute to 10 mL with
water and centrifuge. Dilute a quantity of the supernatant liquid with sufficient
water to produce a solution expected to contain 0.0005% w/v of cyanocobalamin.
chromatographic conditions
(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 361 nm.
(f) Inject 100 µL of each solution.
mobile phase
1 volume of methanol and 3 volumes of a pH 3 buffer solution prepared by mixing 1000 mL of a 2.1% w/v solution of citric acid with 250 mL of a 2.84% w/v solution of anhydrous disodium hydrogen orthophosphate.
determination of content
Calculate the content of C63H88CoN14O14P in cyanocobalamin BPCRS as specified in the leaflet which accompanies cyanocobalamin BPCRS.
Calculate the content of cyanocobalamin, C63H88CoN14O14P, in each tablet using the calculated content of C63H88CoN14O14P in cyanocobalamin BPCRS.
Assay
Use the average of the individual results determined in the test for Uniformity of content.
Storage
Cyanocobalamin Tablets should be protected from light.
LABELLING
When vitamin B12 tablets are prescribed or demanded, Cyanocobalamin Tablets shall be dispensed or supplied.