Metyrapone Capsules
Action and use
11-Beta hydroxylase inhibitor; inhibition of the formation of corticosteroids.
Definition
Metyrapone Capsules contain Metyrapone.
Content of metyrapone, C14H14N2O
95.0 to 105.0% of the stated amount.
Identification
TESTS
Related substances
Carry out in subdued light the method for thin-layer chromatography, Appendix III A, using the following solutions.
5 volumes of 13.5m ammonia, 5 volumes of water and 90 volumes of propan-2-ol.
Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (0.2%).
Assay
Weigh 10 capsules. Open the capsules carefully without loss of shell material, express as much of the contents as possible and reserve the expressed material. Wash the shells with ether, discard the washings, allow the shells to stand at room temperature for about 5 minutes and weigh. The difference between the weights represents the weight of the total contents. Dissolve a quantity of the contents containing 0.1 g of Metyrapone in 40 mL of 0.1m hydrochloric acid and add sufficient 0.1m hydrochloric acid to produce 100 mL. Dilute 5 mL to 50 mL with 0.1m hydrochloric acid and dilute 5 mL of this solution to 50 mL with 0.1m hydrochloric acid. Measure the absorbance of the resulting solution at the maximum at 260 nm, Appendix II B. Calculate the content of C14H14N2O in the capsules taking 500 as the value of A(1%, 1 cm) at the maximum at 260 nm.
Storage
Metyrapone Capsules should be protected from light.