Brit ritish ish Pharmac rmaco opoeia eia 2009 Onlin line
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British Pharmacopoeia Volume III Formulated Preparations: Specific Monographs
Paracetamol Tablets General Notices Action and use
Analgesic; antipyretic. DEFINITION
Paracetamol Tablets contain Paracetamol. The tablets comply with the requirements stated under Tablets and with the foll owing requirements. Content of paracetamol, C8H9NO2
95.0 to 105.0% of the stated amount. amount. IDENTIFICATION
Extract a quantity of the powdered tablets containing 0.5 g of Paracetamol Paracetamol with 20 ml of acetone of acetone,, filter, evaporate the filtrate to dryness and dry at 105°. The residue complies with the following tests. A. Theinfrared Theinfrared absorption spectrum spectrum, Appendix II A, is concordant with the reference spectrum of paracetamol (RS ( RS 258 ). ). B. Boil 0.1 g with 1 ml of hydrochloric of hydrochloric acid for acid for 3 minutes, add 10 ml of water of water and and cool; no precipitate precipi tate is produced. Add 0.05 ml of 0.0167M potassium dichromate; dichromate ; a violet colour is produced slowly which does not turn red. C. Melting point , about 169°, Appendix V A. TESTS Dissolution
Comply with the requirements for Monographs of the British Pharmacopoeia in the dissoluti on test for tablets and capsules capsules,, Appendix XII XII B1, using Apparatus 2. Use as the medium 900 ml of phosphate buffer pH 5.8 and 5.8 and rotate the paddle at 50 revolutions per minute. Withdraw a sample of 20 ml of the medium and filter. Dilute Dil ute the filtrate filtrat e with 0.1M sodium hydroxide to give a solution expected to contain about 0.00075% w/v of Paracetamol. Measure the absorbance of this solution, Appendix II B, at the maximum at 257 nm using 0.1M sodium hydroxide in the reference cell. Calculate the total content of paracetamol, C 8H9NO2, in the medium taking 715 as the value of A(1%, A(1%, 1 cm) at at the maximum maximum at 257 nm. Related substances substances
Carry out the method for liquid for liquid chromatography , Appendix III D, using the following solutions. Prepare the solutions immediately before use and protect from light. For solution (1) disperse a quantity of powdered tablets containing 0.2 g of Paracetamol Paracetamol in 8 ml of the mobile phase with the aid of ultrasound, add sufficient sufficie nt mobile phase to produce 10 ml, mix mix well and filter. filter . For solution (2) dilute 1 volume of solution (1) to 20 volumes with mobile mobile phase and dilute 1 volume of of this solution to 20 volumes with mobile mobile phase. Solution (3) contains 0.002% w/v each of 4-aminophenol of 4-aminophenol and and paraceta paracetamol mol BPCRS in the mobile phase. phase. Solution (4) contains 0.00002% w/v of 4′-chloroacetanilide of 4′-chloroacetanilide in the mobile phase. phase . The chromatographic procedure may be be carried out using (a) a stainless steel column (25 cm × 4.6 mm) mm) packed with octylsilyl silica gel for chromatography (5 chromatography (5 m) m) (Zorbax Rx C8 is suitable), suitable) , (b) as the mobile phase with a flow rate of 1.5 ml per minute, minute, at a temperature of 35°C, a mixture mixture of 250 volumes of methanol of methanol containing 1.15 g of a 40% v/v solution of tetrabutylammonium of tetrabutylammonium hydroxide with 375 volumes of 0.05M disodium hydrogen orthophosphate orthophosphate and 375 volumes of 0.05M sodium di hydrogen hydrogen orthophosphate and (c) a detection wavelengt h of 245 nm. The test is not valid unless, in the chromatogram obtained with solution (3), the resolution factor between factor between the two principal peaks is at least 4.0. Inject solution (1) and allow the chromatography to proceed for 12 times the retention time of the principal peak. In the chromatogram obtained with solution (1) the area of any peak corresponding to 4-aminophenol is not greater than the area of the corresponding peak in solution (3) (0.1%), the area of any peak corresponding to 4′-chloroacetanilide is not greater than the area of the principal peak in solution (4) (10 ppm) and no other impurity is greater than the area of the principal peak obtained with solution (2) (0.25%).
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British Pharmacopoeia 2009 Online
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ASSAY
Weigh and powder 20 tablets. Add a quantity of the powder containing 0.15 g of Paracetamol to 50 ml of 0.1M sodium hydroxide, dilute with 100 ml of water , shake for 15 minutes and add sufficient water to produce 200 ml. Mix, filter and dilute 10 ml of the filtrate to 100 ml with water . Add 10 ml of the resulting solution to 10 ml of 0.1M sodium hydroxide, dilute to 100 ml with water and measure the absorbance of the resulting solution at the maximum at 257 nm, Appendix II B. Calculate the content of C8H9NO2 taking 715 as the value of A(1%, 1 cm) at the maximum at 257 nm. STORAGE
Paracetamol Tablets should be protected from light. © Crown Copyright 2008
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