Calciferol tablets

VII.a.2.2. Treatment. Treatment of established vitamin D deficiency requires much larger doses of vitamin D, such as calciferol tablets of 1 mg (40,000 units) daily. Newer but more expensive preparations such as alfa-calcidol and calcitriol are very effective, and are particularly valuable in patients with renal failure who are unable to hydroxylate calciferol. Patients treated with pharmacological doses of vitamin D preparations must be monitored by checking serum calcium at regular intervals because of the risk of inducing hypercalcaemia. This should always be suspected if patients develop thirst, nausea or vomiting. The newer hydroxylated preparations have a shorter effective half-life, and therefore problems of overdosage are quicker to resolve once identified. 

Decomposition products of calciferol appear to give practically no colour with antimony trichloride- acetyl chloride reagent, and the colorimetric method applied direct to a chloroformic extract of a decomposed sample of calciferol, or of ground tablet material, gives the same result before and after chromatography. In the case of the comparatively low-potency oily solutions of calciferol where the phytosterols present in the oil give colours which interfere, chromatography is necessary. 

Tablets of Calciferol, B,P, Contain 1 25 mg, equivalent to 50,000 units of vitamin D.

Finely powder about 20 tablets and weigh out accurately an amount equivalent to about 250,000 units of calciferol into a stoppered cylinder. Add by pipette 20 ml of light petroleum (b.p. 40° to 60°) and shake for one hour. Allow the insoluble material to settle and pipette 2 ml of the clear supernatant liquid into a 150-ml flask. Evaporate to dryness under nitrogen and dissolve the residue in 20 ml ethanol-free chloroform. 

Dissolve the residue in exactly 1 ml of ethanol-free chloroform and add 9 ml antimony trichloride reagent. Determine the units of vitamin D per tablet as described under Solution of Calciferol. 

---