Storage Store in well-.closed containers.STANDARDSAcetazolamide contains not less than 98 .5 per cent and not more than 101.0 per cent

quantity of the powder equivalent to about 0. 1 g of Acebutolol Hydrochloride. shake with 40 ml of O IM hydrochloric acid and add sufficient water to produce 100. 0 ml, filter and dilute 10. 0 ml of the filtrate to 100. 0 ml with water Dilute 10. 0 ml of this solution to 100. 0 ml with water and measure the absorbance of the resultong solution at the maximum at about 233 nmb Appendix 5.5. Calculate the content of C18H28N2O4,HCL taking 580 as the value of A(1 %. 1 cm) at the maximum at about 233 nm.ACETAZOLAMIDEAcetazolamide is N-(5-sulphamoyl-1,3,4-thiadiazol-2-yl)acetamide Category Carbonic anhydrase inhibitor, used in the treatment of glaucoma Dose Initial dose, 500 mg. subsequent doses. 250 mg every six hours Description White ro faintly yellowish-white, crystalline powder, odourless Solubility Slightly soluble in ethanol (95%), very slightly soluble in water, practically insoluble in chloroform and in ether. It is soluble in dilute solutions of alkali hydroxides. Storage Store in well-.closed containers.STANDARDSAcetazolamide contains not less than 98 .5 per cent and not more than 101.0 per cent of C4H6N4O3S2, calculated with reference to the dried substance .Identification Test A may be omitted if tests B. C and D are carried out. Tests C and D may be omitted if tests A and B are carried out.A The infra-red absorption spectrum. Appendix 5 .4, is concordant with the reference spectrum of acetazolamide or with the spectrum obtained from acetazolamide RS. If the spectra are not concordant, dissolve the substance being examined as well as the reference substance, if used, in methanol. evaporate the solutions to dryness and prepare new spectra B The light absorption in the range 230 to 260 nm of a 0 003% w/v solution in 0.01M sodium hydroxide exhibits a maximum at about 240 nm, absorbance at about 240 nm, 0.54 to 0.59. The light absorption in the range 260 to 360 rim. of a 0.00075% w/v solution in 0.01 M sodium hydroxide exhibits a maximum at about 292 nm. absorbance at about 292 nm, 0.43 to 0.47. Appendix 5.5 C. To about 20 mg in a test-tube add 4 ml of 2M hydrochloric acid and 0.2 g of zinc powder and immediately place a piece of lead acetate paper over the mouth of the Tube, the paper exhibits a brownish-black colour.D: To about 25 rng add 5 ml of water, 4 drops of I M sodium hydroxide and 2 drops of cupric sulphate solution, a bluish-green colour or precipitate is produced Silver-reducing substances Mix 5 g with 25 ml of ethanol (95%), add 125 ml of water. 10 ml of nitric acid and 5 ml of O.1 M silver nitrate, stir for 30 minutes and filter Wash the residue with water, mix the filtrate and washings and titrate the excess of silver nitrate in the mixture with O. OSM ammonium thiocyanate using ferric ammonium sulphate solution as indicator, not less than 9.5 ml of O.OSM ammonium thiocyanate is required Heavy metals Not more than 20 ppm, determined by Method C on 1.0 g dissolved in a mixture of 10 ml of IM sodium hydroxide and 15 ml of water. Appendix 3.12. Related substances :Carry out the method for thin-layer chromatography. Appendix4.6, using silica gel GF254 as the coating substance and a freshly prepared mixture of 50 volumes of 2-propanol, 30 volumes of ethyl acetate and 20-volumes of strong ammonia solution as the mobile phase Do not line the walls of-the tank and allow to saturate for 1 hour before development Apply separately to the plate 20 u1 of each of two solutions of the substance being examined in a mixture of equal volumes of ethanol (95%) and ethyl acetate containing (1) 0 50% w/v and (2) 0.0050% w/v After removal of the plate, allow it to dry in air and examine under ultra-violet light (254 nmj Any secondary .spot in the chromatogram obtained withsolution on (1) !s not more intense than the spot in the chromatogram obtained with solution (2) Sulphated ash Not more than 0.1%. Appendix 3.22 Loss on drying Not more than 0.5%, determined on 2.5 g, Appendix 8.6 Assay Weigh accurately about 0.4 g. dissolve in 90 ml of dimethylformamide and carry out Method A for non-aqueous titration.' Appendix 3.45. using O IM tetrabutylammonium hydroxide as titrant and determining the end-point potentiometrically (Take precautions to prevent absorption of atmospheric carbon dioxide). Perform a blank determination and make any necessary correction Each ml of O.IM tetrabutylammonium hydroxide is equivaalent to 0.02222 g of C4H6N4O3S2ACETAZOLAMIDE TABLETSUsual strength: 250 mg. Storage Store in well-closed containers STANDARDSAcetazolamide Tablets contain not less than 95.0 per cent and not more than 105.0 per cent of the stated amount of acelazolamide, C4H6N4O3S2, Identification: A: To a quantity