Carbamazepine is 5H-dibenz(b,flazepine-5-carboxamide. Category: Anticonvulsant. Dose: 200 mg daily, increasing to 1.2 g daily, in divided doses, in ac

heating Sucrose or Dextrose until the sweet taste is destroyed. Category: Pharmaceutical aid (colouring agent). Description: Thick, free-flowing, dark brown liquid; odour, slight and characteristic.Solubility Miscible with water, with dilute alcohols (upto 60% v/v), with dilute mineral acids and with solutions of sodium hydroxide; immiscible with chloroform and with ether. It is precipitated by strong alcohols (more than 60% v/v).Storage: Store in tightly-closed containers. STANDARDS Identification: To 20 ml of a 5% w/v solution add 0.5 ml of phosphoric acid; no precipitate is produced Weight per ml: Not less than 1.30 g. Appendix 3.15 pH: Between 3.0 and 5.5, determined in a 10% w/v solution, Appendix 8.11. Acid-stability Dilute 50 ml of a 1 % w/v solution to 250 ml with water, add 5 ml of hydrochloric acid and heat gently to boiling under reflux. Allow to cool and set aside for 24 hours; the solution remains clear. Repeat the test on the same testsolution but boil for 30 minutes; the solution remains clear for 24 hours. Heavy metals Not more than 10 ppm, determined on 2 g by Method B, Appendix 3.12 Iron: Evaporate 0.44 g to dryness, add 0.2 ml of nitric acid, ignite and dissolve the residue in 1 ml of dilute nitric acid: the solution complies with the limit test for iron, Appendix 3.13 (100 ppm). Sulphated ash: Not more than 2.0%, Appendix 3.22. Microbial limits: 1.0 g is free from Escherichia coli andsalmonellae, Appendix 9.4. Carbamazepine is 5H-dibenz(b,flazepine-5-carboxamide. Category: Anticonvulsant. Dose: 200 mg daily, increasing to 1.2 g daily, in divided doses, in accordance with the needs of the patient. Description: White or yellowish-white, crystalline powder; almost odourless; exhibits polymorphism.Solubility Freely soluble in dichloromethane, soluble in ethanol (95%) and in acetone; practically insoluble in water and in ether.Storage: Store in well-closed containers. STANDARDSCarbamazepine contains not less than 97.0 per cent and not more than 103.0 per cent of C15H12N2O, calculated with reference to the dried substance. Identification: A: Heat O I g with 2 ml of nitric acid in a water-bath for 3 minutes; an orange-red colour is produced. B: The light absorption in the range 230 to 360 run of a 0.001 % w/v solution in ethanol (95%) exhibits a maximum only at about 285 ran; absorbance at about 285 nm, about 0.49, Appendix 5.5.C: Exhibits an intense blue fluorescence under ultra-violet light (365 nm). D: Melts between 189° and 193°, Appendix 8.8. Acidity or alkalinity: Stir 1 g with 20 ml of carbon dioxide free water for 15 minutes and filter. Titrate 10 ml of the filtrate with 0.1 M sodium hydroxide using 1 drop of phenolphthalein solution as indicator; not more than 0.5 ml is required Add 3 drops of a 0.05% w/v solution of methyl red and titrate with 0.01M hydrochloric acid until the colour changes to red; not more than 1.0 ml is required Chloride: 1.5 g complies with the limit test for chlorides, Appendix 3.10 (165 ppm). Heavy metals: Not more than 10 ppm, determined on 2.0 g by method B, Appendix 3.12. Related substances: Carry out the method for thin-layer chromatography. Appendix 4.6, using silica gel G as the coating substance and a mixture of 95 volumes of toluene and 5 volumes of methanol as the mobile phase. Apply separately to the plate 10 g1 of (1) a 2.5% w/v solution of the substance being examined in chloroform; (2) a 0.005% w/v solution of iminodibenryl RS in methanol. After removal of the plate allow it to dry in air for 15 minutes and spray with a 0.5% w/v solution of