February 2018 Draft for comment 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 AMOXICILLIN AND CLAVULANIC ACID TABLETS Draft proposal for The International Pharmacopoeia (February 2018) DRAFT FOR COMMENT Gg Should you have any comments DRAFT on this FOR draft, COMMENTS please send these to Dr Herbert Schmidt, Medicines Quality Assurance Programme, Technologies Standards and Norms, Department of Essential Medicines and Health Products, World Health Organization, 1211 Geneva 27, Switzerland; fax: (+41 22) 791 4730 or email: schmidth@who.int by 13 April 2018. In order to speed up the process for receiving draft monographs and for sending comments, please let us have your email address (to bonnyw@who.int) and we will add it to our electronic mailing list. Please specify if you wish to receive monographs. World Health Organization 2018 All rights reserved. This draft is intended for a restricted audience only, i.e. the individuals and organizations having received this draft. The draft may not be reviewed, abstracted, quoted, reproduced, transmitted, distributed, translated or adapted, in part or in whole, in any form or by any means outside these individuals and organizations (including the organizations' concerned staff and member organizations) without the permission of the World Health Organization. The draft should not be displayed on any website. Please send any request for permission to: Dr Sabine Kopp, Manager, Medicines Quality Assurance Programme, Technologies Standards and Norms, Department of Essential Medicines and Health Products, World Health Organization, CH-1211 Geneva 27, Switzerland. Fax: (41-22) 791 4730; email: kopps@who.int. The designations employed and the presentation of the material in this draft do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or of certain manufacturers products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters. All reasonable precautions have been taken by the World Health Organization to verify the information contained in this draft. However, the printed material is being distributed without warranty of any kind, either expressed or implied. The responsibility for the interpretation and use of the material lies with the reader. In no event shall the World Health Organization be liable for damages arising from its use. This draft does not necessarily represent the decisions or the stated policy of the World Health Organization.
page 2 46 47 48 49 SCHEDULE FOR THE ADOPTION PROCESS OF DOCUMENT QAS/16.660: AMOXICILLIN AND CLAVULANIC ACID TABLETS Drafting of the monograph by a WHO Collaborating Centre based on information found pharmacopoeias and the scientific literature and based on laboratory investigations Discussion at informal consultation on quality control laboratory tools and specifications for medicines Date October 2015 January 2016 9 11 May 2016 Presentation to WHO Expert Committee on Specifications for Pharmaceutical Preparations Discussion at informal consultation on quality control laboratory tools and specifications for medicines Presentation to WHO Expert Committee on Specifications for Pharmaceutical Preparations Draft revision sent out for public consultation October 2016 2 4 May 2017 October 2017 February to April 2018 Further follow-up action as required 50 51 52 53
page 3 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 AMOXICILLIN AND CLAVULANIC ACID TABLETS (Amoxicillini et acidi clavulanici compressi) [Note from the Secretariat. It is proposed to include the monograph on Amoxicillin and clavulanic acid tablets in The International Pharmacopoeia. The monograph is based on laboratory investigations and on information found in the British Pharmacopoeia, the Chinese Pharmacopoeia, the European Pharmacopoeia and the United States Pharmacopeia.] Category. Antibacterial, β-lactamase inhibitor. Storage. Amoxicillin and clavulanic acid tablets should be kept in a tightly closed container and protected from light. Additional information. Strength in the current WHO Model List of Essential Medicines (EML): 500 mg amoxicillin (as trihydrate) and 125 mg clavulanic acid (as potassium salt). Strength in the current EML for Children: 500 mg amoxicillin (as trihydrate) and 125 mg clavulanic acid (as potassium salt). Labelling. The designation on the container should state that the active ingredients are amoxicillin trihydrate and clavulanate potassium and that the quantities should be indicated in terms of equivalent amounts of amoxicillin and clavulanic acid. 74 Requirements 75 76 77 78 79 80 81 82 83 84 85 86 87 Comply with the monograph for Tablets. Definition. Amoxicillin and clavulanic acid tablets contain amoxicillin trihydrate and clavulanate potassium. They contain not less than 90.0% and not more than 120.0% of the amounts of amoxicillin (C 16 H 19 N 3 O 5 S) and clavulanic acid (C 8 H 9 NO 5 ) stated on the label. Identity test Carry out the test as described under 1.14.4 High-performance liquid chromatography using the conditions given under Assay. The retention times of the two principal peaks in the chromatogram obtained with solution (1) correspond to the retention times of the peaks due to amoxicillin and clavulanic acid in the chromatogram obtained with solution (2). 3
page 4 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 Water. Determine as described under 2.8 Determination of water by the Karl Fischer method, Method A, using a quantity of the powdered tablets; the water content is not more than 100 mg/g. The limit is applicable for tablets 500 mg amoxicillin (as trihydrate). Dissolution. Carry out the test as described under 5.5 Dissolution test for solid oral dosage forms using as the dissolution medium 900 ml of water R and rotating the paddle at 75 revolutions per minute. At 45 minutes withdraw a sample of 10 ml of the medium through an in-line filter and use the filtrate, dilute with water if necessary, to obtain a solution containing the equivalent of about 0.25 mg of amoxicillin per ml (solution (1)). For solution (2) dissolve a suitable amount of amoxicillin trihydrate RS and lithium clavulanate RS in a suitable volume of water R to obtain a solution containing about 0.25 mg of amoxicillin and about 0.0625 mg of clavulanic acid per ml. Carry out the test as described under 1.14.4 High-performance liquid chromatography using the conditions as described under Assay. For each of the tablets tested, calculate the total amount of amoxicillin (C 16 H 19 N 3 O 5 S) and clavulanic acid (C 8 H 9 NO 5 ) in the medium using the declared content of amoxicillin (C 16 H 19 N 3 O 5 S) in amoxicillin trihydrate RS and the declared content of clavulanic acid (C 8 H 9 NO 5 ) in lithium clavulanate RS. The amount of amoxicillin and clavulanic acid in solution for each tablet is not less than 75% (Q) of the amount declared on the label. Clavulanate polymer and other fluorescent impurities. Carry out the test as described under 1.9 Fluorescence spectrophotometry. Prepare the following buffer solution. Dissolve 15.6 g of sodium dihydrogen phosphate R in 800 ml of water R, adjust the ph to 5.0 using sodium hydroxide (~40 g/l) TS and add sufficient water R to produce 1000 ml. Prepare the following solutions freshly. For solution (1) add to a quantity of the powdered tablets, containing the equivalent of 0.1 g of clavulanic acid, 50 ml of the buffer solution. Stir the sample until it is evenly dispersed and add sufficient buffer solution to produce 100.0 ml. Shake the solution vigorously for 1 minute, shake mechanically for 5 minutes, sonicate for 5 minutes and filter. For solution (2) prepare a solution containing 0.42 µg per ml of quinine sulfate R in sulfuric acid (~50 g/l) TS. Measure the fluorescence of the solutions (1) and (2) with an excitation wavelength of
page 5 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 360 nm and an emission wavelength of 440 nm, using the phosphate buffer solution in the reference cell. The fluorescence obtained with solution (1) is not more intense than that obtained with solution (2) (5% w/w, calculated with respect to the content of clavulanic acid). [Note: The fluorescence of quinine sulfate is 118 times more intense than that of an equivalent concentration of clavulanate polymer.]. Related substances. Carry out the test as described under 1.14.4 High-performance liquid chromatography using a stainless steel column (25 cm 4.6 mm) packed with particles of silica gel, the surface of which has been modified with chemically-bonded octadecylsilyl groups (5 μm). 1 Prepare the following buffer solution, ph 5.0: adjust the ph of 250 ml of potassium dihydrogen phosphate (27.2 g/l) TS to 5.0 with sodium hydroxide (~80 g/l) TS and dilute to 1000 ml with water R. Use the following conditions for gradient elution: mobile phase A: mobile phase B: mix 10 volumes of acetonitrile R with 990 volumes of the buffer solution; mix 200 volumes of acetonitrile R with 800 volumes of the buffer solution. Time(min) Mobile Mobile phase B comments phase A 0 tr 92 8 Isocratic tr (tr + 25) 92 to 0 8 to 100 Linear gradient (tr + 25) (tr + 40) 0 100 Isocratic (tr + 40) (tr + 41) 92 8 Return to initial composition (tr + 41) (tr + 55) 92 8 Re-equilibration tr = retention time of amoxicillin determined with solution (1). Prepare the following solutions immediately before use. For solution (1) transfer a quantity of the powdered tablets containing the equivalent of about 30 mg of amoxicillin into a 20 ml volumetric flask, add 15 ml of mobile phase A and sonicate for 20 minutes with occasional shaking. Allow to cool to room temperature, make up to volume with mobile phase A and filter. For solution (2) dilute 1 volume of solution (1) to 100 volumes with mobile phase A. For solution (3) use a solution containing 4 µg of cefadroxil R and 30 μg of amoxicillin RS per ml mobile phase A. For solution (4) use a solution containing 0.75 mg of lithium clavulanate RS per ml mobile phase A. For solution (5) add 1.0 ml of water R to 0.20 g of amoxicillin trihydrate R. Shake 1 Shim-pack CL-ODS C 18 has been found suitable. 5
page 6 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 and add dropwise sodium hydroxide (~80 g/l) TS to obtain a solution. The ph of the solution is about 8.5. Store the solution at room temperature for 4 h. Dilute 0.5 ml of this solution to 50.0 ml with mobile phase A. Operate with a flow rate of 1.0 ml per minute. As a detector use an ultraviolet spectrophotometer set at a wavelength of 254 nm. Inject 50 μl of solution (3) with isocratic elution at the initial mobile phase composition. The test is not valid unless the resolution factor between the peaks due to amoxicillin and cefadroxil is at least 2.0. Inject alternately 50 μl each of solution (4) and (5). Use the chromatogram obtained with solution (4) to identify the peak corresponding to clavulanic acid. Use the chromatogram obtained with solution (5) to identify the peaks corresponding to amoxicillin dimer (impurity J; n = 1) and amoxicillin trimer (impurity J; n = 2). The following impurities and substances are eluted at the relative retention with reference to amoxicillin (retention time about 10 minutes): clavulanic acid about 0.3; amoxicillin dimer (impurity J; n = 1) about 4.1; amoxicillin trimer (impurity J; n = 2) about 4.5. Inject alternately 50 μl each of solution (1) and (2). In the chromatogram obtained with solution (1): the area of any peak corresponding to amoxicillin dimer (impurity J; n = 1) is not greater than twice the area of the principal peak in the chromatogram obtained with solution (2) (2%); the area of any other impurity peak is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (1%). Assay. Carry out the test as described under 1.14.4 High-performance liquid chromatography using a stainless steel column (25 cm 4.6 mm) packed with particles of silica gel, the surface of which has been modified with chemically-bonded octadecylsilyl groups (5 μm). 1 As the mobile phase use a mixture of 5 volumes of methanol R and 95 volumes of sodium dihydrogen phosphate (~7.8 g/l) TS, adjusted to ph 4.4 with phosphoric acid (~1440 g/l) TS. Operate with a flow rate of 2.0 ml per minute. As a detector use an ultraviolet spectrophotometer set at a wavelength of about 220 nm. Prepare the following solutions. For solution (1) weigh and powder 20 tablets.
page 7 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 Transfer a quantity of the powdered tablets containing the equivalent of about 0.25 g of amoxicillin, accurately weighed, into a 500 ml volumetric flask, add 400 ml of water R and shake for 10 minutes. Make up to volume with water R and filter. For solution (2) use 0.5 mg of amoxicillin RS and 0.2 mg of lithium clavulanate RS per ml water R. Inject alternately 20 μl of solution (1) and (2). The assay is not valid unless the resolution factor between the peaks due to amoxicillin and clavulanic acid is at least 3.5 and the symmetry factor of the peak due to clavulanic acid in the chromatogram obtained with solution (2) is less than 1.5. Measure the areas of the peak responding to amoxicillin and clavulanic acid and calculate the content of amoxicillin (C 16 H 19 N 3 O 5 S) and clavulanic acid (C 8 H 9 NO 5 ) in the tablets using the declared content of amoxicillin (C 16 H 19 N 3 O 5 S) in amoxicillin trihydrate RS and the declared content of clavulanic acid (C 8 H 9 NO 5 ) in lithium clavulanate RS. Impurities The impurities limited by the requirements of this monograph include those listed in the monograph on Amoxicillin trihydrate. Reagents and test solutions to be established Phosphoric acid (~7.8 g/l) TS Procedure. Dilute 9,2 g of phosphoric acid (~1440 g/l) TS with sufficient water to produce 1000 ml. Sulfuric acid (~50 g/l) TS Procedure. Mix 500 ml of sulfuric acid (~100 g/l) TS with sufficient water to produce 1000 ml. Quinine sulfate R Quinine sulfate of a suitable quality should be used. Cefadroxil R Cefadroxil of a suitable quality should be used. *** 7