地喹氯铵EP标准.doc

Dequalinium Chloride(Ph Eur monograph 1413) C30H40Cl2N4 527.6 522-51-1 Ph Eur Definition Dequalinium chloride contains not less than 95.0 per cent and not more than the equivalent of 101.0 per cent of 1,1-(decane-1,10-diyl)bis(4-amino-2-methylquinolinium) dichloride, calculated with reference to the dried substance. Characters A white or yellowish-white powder, hygroscopic, slightly soluble in water and in alcohol. Identification First identification B, E. Second identification A, C, D, E. A.Dissolve about 10 mg in water R and dilute to 100 ml with the same solvent. Dilute 10 ml of the solution to 100 ml with water R. Examined between 230 nm and 350 nm (2.2.25), the solution shows 2 absorption maxima, at 240 nm and 326 nm and a shoulder at 336 nm. The ratio of the absorbance measured at the maximum at 240 nm to that measured at the maximum at 326 nm is 1.56 to 1.80 and the ratio of the absorbance measured at the maximum at 326 nm to that measured at the shoulder at 336 nm is 1.12 to 1.30. B.Examine by infrared absorption spectrophotometry between 600 cm-1 and 2000 cm-1 (2.2.24), comparing with the spectrum obtained with dequalinium chloride CRS. C.To 5 ml of solution S (see Tests) add 5 ml of potassium ferricyanide solution R. A yellow precipitate is formed. D.To 10 ml of solution S add 1 ml of dilute nitric acid R. A white precipitate is formed. Filter and reserve the filtrate for identification test E. E.The filtrate from identification test D gives reaction (a) of chlorides (2.3.1). Tests Solution S Dissolve 0.2 g in 90 ml of carbon dioxide-free water R, heating if necessary, and dilute to 100 ml with the same solvent. Appearance of solution Solution S is clear (2.2.1) and colourless (2.2.2, Method II). Acidity or alkalinity To 5 ml of solution S add 0.1 ml of bromothymol blue solution R1. Not more than 0.2 ml of 0.01M hydrochloric acid or 0.01M sodium hydroxide is required to change the colour of the indicator. Related substances Examine by liquid chromatography (2.2.29). Test solution Dissolve 10.0 mg of the substance to be examined in the mobile phase and dilute to 10.0 ml with the mobile phase. Reference solution (a) Dissolve 10.0 mg of dequalinium chloride for performance test CRS in the mobile phase and dilute to 10.0 ml with the mobile phase. Reference solution (b) Dissolve 10.0 mg of dequalinium chloride CRS in the mobile phase and dilute to 10.0 ml with the mobile phase. Dilute 1.0 ml to 50.0 ml with the mobile phase. The chromatographic procedure may be carried out using: a stainless steel column 0.25 m long and 4.6 mm in internal diameter packed with an end-capped octadecylsilyl silica gel for chromatography R, as mobile phase at a flow rate of 1.5 ml/min the following solution: dissolve 2 g of sodium hexanesulphonate R in 300 ml of water R. Adjust to pH 4.0 with acetic acid R and add 700 ml of methanol R, as detector a spectrophotometer set at 240 nm. Adjust the sensitivity of the system so that the height of the peak due to impurity B in the chromatogram obtained with 10 ml of reference solution (a) is at least 25 per cent of the full scale of the recorder. Measure the height (A) above the baseline of the peak due to impurity B and the height (B) above the baseline at the lowest point of the curve separating this peak from the peak due to dequalinium chloride. The test is not valid unless A is greater than twice B. If necessary, adjust the concentration of methanol in the mobile phase. Inject 10 ml of the test solution and 10 ml of reference solution (b). Continue the chromatography of the test solution for 5 times the retention time of the peak due to dequalinium chloride. In the chromatogram obtained with the test solution: the area of any peak due to impurity A is not greater than half the area of the principal peak in the chromatogram obtained with reference solution (b) (1 per cent); and the sum of the areas of all the peaks, apart from the principal peak, is not greater than 5 times the area of the principal peak in the chromatogram obtained with reference solution (b) (10 per cent). Disregard any peak with an area less than 0.025 times the area of the principal peak in the chromatogram obtained with reference solution (b). Readily carbonisable substances Dissolve 20 mg in 2 ml of sulphuric acid R. After 5 min the solution is not more intensely coloured than reference solution BY4 (2.2.2, Method I). Loss on drying (2.2.32) Not more than 7.0 per cent, determined on 1.000 g by drying at 100-105C at a pressure not exceeding 0.7 kPa. Sulphated ash (2.4.14) Not more than 0.1 per cent, determined on 1.0 g. Assay In order to avoid overheating in the reaction medium, mix thoroughly throughout and stop the titration immediately after the end-point has been reached. Dissolve 0.200 g in 5 ml of anhydrous formic acid R and add 50 ml of acetic anhydride R. Titrate with 0.1M perchloric acid, determining the end-point potentiometrically (2.2.20). 1 ml of 0.1M perchloric acid is equivalent to 26.38 mg of C30H40Cl2N4. Storage In an airtight container . Impurit