Indometacin Capsules
Action and use
Cyclo-oxygenase inhibitor; analgesic; anti-inflammatory.
Definition
Indometacin Capsules contain Indometacin.
Content of indometacin, C19H16ClNO4
90.0 to 110.0% of the stated amount.
Identification
TESTS
Dissolution
Comply with the requirements for Monographs of the British Pharmacopoeia in the dissolution test for tablets and capsules, Appendix XII B1.
Calculate the total content of indometacin, C19H16ClNO4, in the medium taking 196 as the value of A(1%, 1 cm) at the maximum at 320 nm.
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
30 volumes of petroleum spirit (boiling range, 60° to 80°) and 70 volumes of ether.
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
To a quantity of the mixed contents of 20 capsules containing 50 mg of Indometacin add 10 mL of water and allow to stand for 10 minutes, swirling occasionally. Add 75 mL of methanol, shake well, add sufficient methanol to produce 100 mL and filter if necessary. To 5 mL of the filtrate add sufficient of a mixture of equal volumes of methanol and phosphate buffer pH 7.2 to produce 100 mL. Measure the absorbance of the resulting solution at the maximum at 320 nm, Appendix II B. Calculate the content of C19H16ClNO4 taking 193 as the value of A(1%, 1 cm) at the maximum at 320 nm.