corresponding to that due to barbalom in the chromatogram obtained with solution

A: The light absorption in the range 230 to 360 nm of the solution obtained in the Assay exhibits a maximum only at about 250 run, Appendix 5.5. B: Comply with the test D described under Allopunnol. Related substances: Compfy' with the test described under Allopunnol using as solution (1) a solution prepared by shaking a quantity of the powdered tablets equivalent to 0.25 g of Allopunnol with 10 ml of strong ammonia solution and filtering. Disintegration: Maximum time, 30 minutes, Appendix 7.1. Other requirements Comply with the requirements of tests stated under Tablets. Assay: Weigh and powder 20 tablets. Weigh accurately a quantity of the powder equivalent to about 0 1 g of Allopunnol and shake with 20 ml of 0 05M sodium hydroxide for 15 to 20 minutes, add 75 ml of 0 1 M hydrochloric acid shake for 1 0 minutes, add sufficient 0.1 M hydrochloric acid to produce 250.0 ml, filter and dilute 5 0 ml of the filtrate to 250.0 ml with 0.1 M hydrochloric acid. Measure the absorbance of the resulting solution at the maximum at about 250 nm, Appendix 5.5, using 0.1 M hydrochloric acid as theblank. Calculate the content of C5H4N4O, taking 563 as the value of A(1%, 1 cm) at the maximum at about 250 nm. ALOESAIoes is die dried juice of the leaves of Aloe barbadensis Miller (A. vera Linn), known in commerce as Curacao Aloes or Barbados Aloes, or of A ferox Miller and hybrids of this species with A. africana Miller and A. spicata Baker, known in commerce as Cape Aloes (Fam. Lihaceae). Indian Aloes of commerce is obtained from A barbadensis. Category: Laxative. Description: Unground Curacao Aloes - Brownish-black, opaque masses; fractured surface uneven, waxy and somewhat resinous; odour, strong and characteristic. Unground Cape Aloes - Dark-brown or greenish-brown to olive-brown masses; fractured surface shiny and conchoidal; odour, strong and characteristic. Solubility: Soluble in hot ethanol (95%); partly soluble in boiling water; practically insoluble in chloroform and in ether. Powdered Aloes is almost entirely soluble in ethanol (60%). Storage: Store in tightly-closed, light-resistant containers, protected from moisture Labelling: The label states whether it is Curacao Aloes or Cape Aloes. STANDARDSAIoes contains not less than 50.0 per cent of water-soluble extractive. Curacao Aloes contains not less than 18. 0 per cent and Cape Aloes not less than 28.0 per cent of hydroxyanthracene derivatives, calculated as anhydrous barbaloin. Identification Mix 0 5 g with 50 ml of water, boil until nearly dissolved, cool, add 0.5 g of silica gel and filter. On the filtrate carry out the following tests .A: Heat 5 ml with 0.2 g of borax until dissolved, add a few drops of this solution to a test-tube nearly filled with water, a green fluorescence is produced. B: Mix 2 ml with 2 ml of bromine water, a pale yellow precipitate is produced. The supernatant liquid is violet with Curacao Aloes; no such violet colour appears with Cape Aloes. C: Mix 5 ml with 2 -ml of nitric acid; with Cape Aloes a reddish-yellow colour is produced; with Socotrme Aloes a pale brownish-yellow colour is produced; with Cape Aloes a yellowish-brown colour passing rapidly to green is produced. D: Carry out the method for thin-layer chromatography, Appendix 4.6, using silica gel G as the coating substance and a mixture of 100 volumes of ethyl acetate, 17 volumes of methanol and 13 volumes of water as the mobile phase. Apply separately to the plate S µl of each of the following solutions, as bands 20 mm long and not more than 3 mm wide For solution (1) heat 0.5 g, in powder, with 20 ml methanol to boiling on a water-bath, shake well, decant the supernatant liquid, keep at 4° and use within 24 hours For solution (2) dissolve 50 mg of barbalom in 10 ml methanol. After removal of the plate, allow it to dry in air, spray with a 10% w/v solution of potassium hydroxide in methanol and examine under ultra-violet light (365 nm). The chromatogram obtained with solution (2) shows a yellow band with an Rf value of 0.4 to 0.5. In the case of Curacao Aloes, the chromatogram obtained with solution (1) shows a yellow flu orescent band corresponding to that due to barbalom in the chromatogram obtained with solution (2) and in the lower part a light blue fluorescent band (corresponding to aloesine). In the case of Cape Aloes, solution (1) shows a yellow fluorescent band corresponding to that due to barbalom in the chromatogram obtained with solution (2) and in the lower part two yellow fluorescent bands (due to alomosides A and B) as well as a blue fluorescent band (due to aloesine). Heat the plate at 110° for 5 minutes. In the case of Curacao Aloes, with solution (1) a violet fluorescent band appears just below the yellow band corresponding to barbalom while in the case of Cape Aloes no such violet band appears. Ethanol-msoluble substances: Weigh accurately about 1 g, in fine powder, and add to 50 ml of ethanol (95%) in a flask. Reflux the