concordant with the reference spectrum of colchicine or with, the spectrum obtained from colchicine RS. B: The light absorption in the ränge 230 to 40

equivalent To TÖ mg of Probenecid with 10 ml of Chloroform, allow to settIe and decant the clear supernatant liquid Solution (4) contains 0.1% w/v öf probenecid RS. After removal of the plate. allow it to dry in air and examine under ultra-violet light (254 nm) the principal spot in thechromatogram obtained with solution (1) corresponds tothat in the chromatogram obtained with solution (2). Sinfilarly, the principal spot in the chromatogram obtamed with solution (3) corresponds to that in the chromatogram obtained with solution (4) Uniformify of content For colchicine - Comply with the requriements stated under tablets using the method descnbed under Assay. Other containers. STANDARDS Colchicine contains not less than 97.0 percent and not more than 103.0 per cent of C22H25NO6, calculaled with referenceto the dned, solvent-freesubstance. Identification Test A may be omitted if tests B, C and D are carried out. tests B, C and D may be omitted if test A is carned out. A: The infra-red absorption spectrum. Appendix 5.4. is concordant with the reference spectrum of colchicine or with, the spectrum obtained from colchicine RS. B: The light absorption in the ränge 230 to 400 ran of a 0.001% w/v solution in ethanol (95%) exhibits two maxima, at about 243 nm and 350 nm: absorbance at about 243 nm, about 0.73 and at about 350 run, about 0.42. Appendix 5.5. C: Dissolve 50 mg in 1.5 ml of water; a yellow solution is produced the colour of which is mtensified on addmg mineral acids. D: Mix 1 mg with 0.2 ml of sulphuric acid in a white dish; a yellow colour is produced which on the addition of 0.05 ml of nitric acid changes to greenish-blue and then rapidly becomes reddish and fmally almost colourless. On addition of an excess of 5M sodium hydroxide the colour changes to. red. Specific optical rotation: Between -235◦ and '-250◦,, determined at 20◦ in a 0.5% w/v solution, Appendix 8.9. Colchiceine: To 5 ml of a 1.0% w/v solution add 0.1 ml of a 10.5% w/v solution of ferric chloride. Any colour produced is not more mtense than that obtained by mixing 2.0 ml of FCS with 1.0 ml of CCS and