Menadiol Phosphate Tablets
Action and use
Vitamin K analogue.
Definition
Menadiol Phosphate Tablets contain Menadiol Sodium Phosphate.
Content of menadiol phosphate, C11H12O8P2
92.5 to 107.5% of the stated amount.
Identification
Tests
Related substances
Carry out in subdued light the method for thin-layer chromatography, Appendix III A, using silica gel GF254 as the coating substance and a mixture of 50 volumes of propan-1-ol, 50 volumes of a 2% w/v solution of ammonium chloride, 5 volumes of butan-1-ol and 1.5 volumes of diethylamine as the mobile phase. Apply separately to the plate 5 µL of each of the following solutions. For solution (1) shake a quantity of the powdered tablets containing the equivalent of 0.25 g of menadiol phosphate with 10 mL of methanol (50%) and filter. For solution (2) dilute 1 volume of solution (1) to 200 volumes with methanol (50%). Solution (3) contains 0.0080% w/v of 2-methyl-1,4-naphthoquinone in methanol. After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm). Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (3). Examine the plate under ultraviolet light (365 nm). Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2).
Assay
Weigh and powder 20 tablets. Shake a quantity of the powder containing the equivalent of 10 mg of menadiol phosphate with 100 mL of 0.1m hydrochloric acid for 30 minutes. Dilute to 250 mL with 0.1m hydrochloric acid, filter and measure the absorbance of the filtrate at the maximum at 290 nm, Appendix II B. Calculate the content of C11H12O8P2 taking the value of A(1%, 1 cm), for a solution of C11H8Na4O8P2 in 0.1m hydrochloric acid, to be 138 at the maximum at 290 nm. Each mg of C11H8Na4O8P2 (menadiol sodium phosphate) is equivalent to 0.792 mg of C11H12O8P2 (menadiol phosphate).
Labelling
The quantity of active ingredient is stated in terms of the equivalent amount of menadiol phosphate.