. Acid-insoluble ash: Not more han 1.0% in Sumatra Benzoin and not more than 0.5% in Siam Benzoin, determmed on 2 g, Appendix 3.39 Loss on drying: Not

75.0% in Sumatra Benzoin and not less than 90.0% in Siam Benzoin, determined by the following method. Weigh accurately about 2 g, in coarse powder, in a tared extraction thimble and insert the thimble in a Soxhlet or other suitable continuous extraction apparatus Place 0.1 g of sodium hydroxide in the receiving flask of the apparatus, extract with ethanol (95%) until extraction is complete (about 5 hours), dry the thimble lo constant weight at 105° and calculate the ethanol soluble extractive from the increase in weight of the thimble. Acid-insoluble ash: Not more han 1.0% in Sumatra Benzoin and not more than 0.5% in Siam Benzoin, determmed on 2 g, Appendix 3.39 Loss on drying: Not more than 10.0%, determined on 2 g, in coarse powder, by drying over phosphorus pentoxide al a pressure not exceeding 2.7 kPa for 4 hours, Appendix 8.6 Assay: Weigh accurately about 1.25 g and boil with 25 ml of dilute ethanolic potassium hydroxide solution under a reflux condenser for 1 hour. Remove the ethanol and digest the residue with 50 ml of hot waler until diffused Cool the liquid, add 150 ml of water and 1.5 g of magnesium sulphate dissolved in 50 ml of water Mix thoroughly and sel aside for 10 minutes. Filter, wash the residue on the filter with 20 ml of water, acidify the combined filtrate and washings with hydrochloric acid and extract with successive quantities of 50, 40, 30, 30 and 30 ml of ether Combine the ether extracts and discard the aqueous portion. Extract with successive quanlilies of 20, 20, 10, 10 and 10 ml of sodium bicarbonate solution, washing each aqueous extract with the same 20 ml of ether. Discard the ether layers, acidify the combined aqueous extracts with hydrochloric acid and extract with successive quantities of 30, 20, 20 and 10 ml of chloroform, filtering each chloroform extract through a plug of cotton wool on which a layer of anhydrous sodium sulphate is placed Evaporate the chloroform on a water-bath until about 10 ml remains and remove the remainder in a current of air stopping immediately when the last trace of solvent is removed. Dissolve the residue by warming with 10 ml of ethanol (95%), previously neutralised lo phenol red solution, cool and titrate with 0. IM sodium hydroxide using phenol red solution as indicator. Each ml of 0.1 M sodium hydroxide is equivalent to 0.01482 g of total balsamic acids, calculated as cinamic acid, C9H8O2, in Sumatra Benzoin and 0.01221 g of total balsamic acids, calculated as benzoic acid, C7H60?, in Siam Benzoin. COMPOUND BENZOIN TINCTURE Friars' BalsamBenzom, in moderatety coarse powder Macerate the Benzoin, Prepared Storax, Tolu Balsam and Aloes with 800 ml of Ethanol (90%n) in a closed vessel for not less than 2 days with occasional shaking Filler and pass sufficient Elhanol (90%) through the filter to produce the required volume Category: Topical protectant, expeclorant and comforting by steam inhalation in acute laryngitis,. Storage Slore in tighlly-closed, hght-resislant containers and avoid exposure to direcl sunlight and lo excessive heat Labelling: The label slates that it is flammable. STANDARDSCompound Benzoin Tincture contains not less lhan 45 per cent w/v of lotal balsamic acids, calculated as cinnamic acid, CgH8Oldentification: A: Complies with lest D described under Benzoin using as solution (1) a solution prepared by diluting 1 ml with 4 ml of elhanol (95°I0) .[The chromatographic profile may vary depending on the variety of Benzoin used). B: Carry out test D described under Benzoin but using Ihe following solutions For solulion. (1) dilute 1 ml with 4 ml of elhanol (95%). Solution (2) is a 0.05% w/v solulion of styrene RS in chloroform. The chromatogram obtained with solution (1) exhibits an intense spot corresponding to the spol in the chromalogram obtained wilh solution (2) (Prepared Slorax). C: Carry out test D described under Benzoin but using the following solutions. For solution (1) dilute 1 ml with 4 ml of ethanol (95%). Solutions (2), (3), (4) and (5) are 0.05% w/v solutions of benzoyl benzoate RS, benzoyl cinnamate RS, eugenol RS and vanillin RS respectively in chloroform. The chromatogram obtained with solution (1) exhibits spots corresponding to the spots in the chromatogram obtained with solutions (2), (3), (4) and (5) (Tolu Balsam). 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, 13.5 volumes of methanol arid 10 volumes of water as the mobile phase but allowing the solvenl front to ascend 10 em above the line of application Apply separately to the plate 50 ul of each of the following solutions as bands 20 mm long and nol more than 3 mm wide For solulion (1) dilute 1 ml with 4 ml of ethanol (95%). For solution (2) use a 0.5% w/v solution of barbalom RS m methanol. After removal of the plate, allow it to dry in air until the odour of the solvenl is no longer detectable, spray with a 10% w/v solution of potassium hydroxide m methanol and examine under ultra-violet light (365 nm). The chromatogram obtained with solution (1) exhibits a yellow fluorescent band corresponding to the band obtained m the chromatogram obtained with solution (2) and a light blue fluorescent band wilh a lower Rf value due to alcesine. Heat the plate al 110° for 5 minutes; a violet fluorescent band just below the band corresponding to barbaltion may also be seen in the chromatogram obtained with solution (1) (Aloes). Weight per ml: Between 0.870