Document JvN4OZ93GZzDjogYD36ZVaNY6

FILE NAME Talc TALC DATE 2011 Aug 1 DOC TALC203 DOCUMENT DESCRIPTION US Pharma Revised Bulletin on Talc Revision Bulletin Official August 1 2011 Talc 1 Talc DEFINITION Talc is a powdered selected natural hydrated magnesium silicate Pure talc has the formula Mg3Si4O10 It may contain variable amounts of associated minerals among which chlorites hydrated aluminum and magnesium silicates magnesite magnesium carbonate calcite calcium carbonate and dolomite calcium and magnesium carbonate are predominant IDENTIFICATION A. INFRARED ABSORPTION The IR spectrum of a potassium bromide dispersion of it exhibits maxima at 3677 cm at 1018 cm and at 669 cm B. PROCEDURE Sample 100 mg Analysis Mix about 200 mg of anhydrous sodium car- bonate and 2 g of anhydrous potassium carbonate and melt in a platinum crucible To the melt add the Sample and continue heating until fusion is complete Cool and transfer the fused mixture to a dish or beaker with the aid of about 50 mL of hot water Add hydrochloric acid to the liquid until effervescence ceases then add 10 mL more of the acid and evaporate the mixture on a steam bath to dryness Cool add 20 mL of water boil and filter the mixture Save the insoluble residue for use in Identification test C. To 5 mL of the filtrate add 1 mL of 6 N ammonium hydroxide and 1 mL of ammonium chloride TS Filter if necessary and add 1 mL of dibasic sodium phosphate TS to the filtrate Acceptance criteria A white crystalline precipitate of magnesium ammonium phosphate is formed . C. PROCEDURE Sample 100 mg of the insoluble residue from Identifica- tion test B Analysis In a lead or platinum crucible and using a copper wire mix the Sample with about 10 mg of sodium fluoride and a few drops of sulfuric acid to give a thin slurry Cover the crucible with a thin transparent plate of plastic under which a drop of water is suspended and warm gently Acceptance criteria Within a short time a white ring is rapidly formed around the drop of water ASSAY CONTENT OF MAGNESIUM Lanthanum chloride solution To 5.9 g of lanthanum oxide slowly add 10 mL of hydrochloric acid and heat to boiling Allow to cool and dilute with water to 100 mL Magnesium standard stock solution 10 mL of magnesium prepared by diluting an 8.365 mL solution of magnesium chloride in diluted hydrochloric acid with water 1 in 100 Magnesium standard solutions Into four identical 100 volumetric flasks each containing 10.0 mL of hydrochloric acid and 10 mL of Lanthanum chloride solution transfer respectively 2.5 3.0 4.0 and 5.0 mL of Magnesium standard stock solution and dilute with water to volume Sample stock solution Caution Perchlorates mixed with heavy metals are known to be explosive Take proper precautions while performing this analysis Weigh 500 mg of Talc in a 100 polytetrafluoroethylene dish Add 5 mL of hydrochloric acid 5 mL of leadfree nitric acid and 5 mL of perchloric acid Stir gently then add 35 mL of hydrofluoric acid and evaporate slowly on a hot plate to moist dryness until about 0.5 mL remains To the residue add 5 mL of hydrochloric acid cover with a watch glass heat to boiling and allow to cool Rinse the watch glass and the dish with water transfer to a mL volumetric flask and dilute with water to volume Sample solution Dilute the Sample stock solution with water 1 in 200 Transfer 4.0 mL of this solution to a 100 volumetric flask add 10.0 mL of hydrochloric acid and 10 mL of Lanthanum chloride solution and di- lute with water to volume Instrumental conditions See Spectrophotometry and Scattering 851 wavelength Mode Atomic absorption spectrophotometry Analytical Magnesium emission line at 285.2 nm Lamp Magnesium cathode Flame acetylene Analysis Samples Magnesium standard solutions solution and Sample Concomitantly determine the absorbance of the solutions Acceptance criteria -19.5 IMPURITIES SOLUBLE SUBSTANCES Sample 10.0 Analysis To the Sample add 50 mL of carbon dioxide- free water heat to boiling and boil under a reflux condenser for 30 min Allow to cool filter and dilute with carbon dioxide water to 50.0 mL Test with litmus paper Evaporate 25.0 mL of the filtrate to dryness dry at 105 for 1 h and weigh the residue Acceptance criteria The filtrate is neutral to litmus paper and the weight of the residue is NMT 5 mg 0.1 LIMIT OF IRON Iron standard stock solution 250 mL of iron from 4.840 g ferric chloride in a 150 g solution of hydrochloric acid in water Prepare immediately before use Iron standard solutions Into four 100 volumetric flasks each containing 50.0 mL of 0.5 N hydrochloric acid transfer respectively 2.0 2.5 3.0 and 4.0 mL of the Standard iron stock solution and dilute each flask with water to volume Sample stock solution Transfer 10.0 g of Talc to a conical flask fitted with a reflux condenser Gradually add 50 mL of 0.5 N hydrochloric acid while stirring and heat on a water bath for 30 min Allow to cool Transfer the mixture to a beaker and allow the undissolved material to settle Filter the supernatant into a 100 volumetric flask retaining as much as possible of the insol- uble material in the beaker Wash the residue and the beaker with three mL portions of hot water Wash the filter with 15 mL of hot water allow the filtrate to cool and dilute with water to 100.0 mL Sample solution Transfer 2.5 mL of the Sample stock solution to a 100 volumetric flask add 50.0 mL of 0.5 N hydrochloric acid and dilute with water to volume Instrumental conditions See Spectrophotometry and Scattering 851 Mode Atomic absorption spectrophotometry Analytical wavelength Iron emission line at 248.3 nm Lamp Iron cathode Flame acetylene Analysis Samples Iron standard solutions and Sample solution Concomitantly determine the absorbance of the solutions Make any correction using a deuterium lamp 2011 The United States Pharmacopeial Convention All Rights Reserved 2 Talc Revision Bulletin Official August 1 2011 Acceptance criteria LIMIT OF LEAD NMT 0.25 Sample solution Use the Sample stock solution as di- rected in the test for Limit of Iron Diluent Nitric acid in water ( in 100 Lead standard stock solution 10 mL of lead pre- pared as follows Dissolve 160 mg of lead nitrate in 100 mL of Diluent and dilute with water to 1000 mL Dilute this solution with water 1 in 10 Lead standard solutions Into four identical 100 volumetric flasks each containing 50.0 mL of 0.5 N hydrochloric acid transfer respectively 5.0 7.5 10.0 and 12.5 mL of Lead standard stock solution and dilute with water to volume Instrumental conditions See Spectrophotometry and Scattering 851 wavelength Mode Atomic absorption spectrophotometry Analytical Lead emission line at 217.0 nm Lamp Lead cathode Flame acetylene Analysis Samples Lead standard solutions and Sample solution Concomitantly determine the absorbance of the solutions Acceptance criteria LIMIT OF CALCIUM NMT 10 ppm Lanthanum chloride solution Prepare as directed in the Assay Calcium standard stock solution 100 mL of cal- immediately cium prepared before use by diluting a 3.67 mg solution of calcium chloride dihydrate in diluted hydrochloric acid with water ( in 10 Calcium standard solutions Into four identical 100 volumetric flasks each containing 10.0 mL of hydrochloric acid and 10 mL of Lanthanum chloride solution transfer respectively 1.0 2.0 3.0 and 4.0 mL of Calcium standard stock solution and dilute each solution with water to volume Sample stock solution Prepare as directed in the Assay Sample solution Transfer 5.0 mL of the Sample stock solution to a 100 volumetric flask add 10.0 mL of hydrochloric acid and 10 mL of Lanthanum chloride solution and dilute with water to volume Instrumental conditions See Spectrophotometry and Scattering 851 wavelength Mode Atomic absorption spectrophotometry Analytical Calcium emission line at 422.7 nm Lamp Calcium cathode Flame Nitrous acetylene Analysis Samples Calcium standard solutions solution and Sample Concomitantly determine the absorbance of the solutions Acceptance criteria LIMIT OF ALUMINUM NMT 0.9 Cesium chloride solution ride in water 25.3 mg of cesium chlo- Aluminum standard stock solution 100 mL of aluminum prepared immediately before use by diluting an 8.947 mL solution of aluminum chloride in water with water ( in 10 Aluminum standard solutions Into four identical 100- mL volumetric flasks each containing 10.0 mL of hydrochloric acid and 10 mL of Cesium chloride solution transfer respectively 5.0 10.0 15.0 and 20.0 mL of Alumi- volume standard stock solution and dilute with water to volume Sample stock solution Proceed as directed in the As- say Transfer 5 mL of the Cesium chloride solution to the mL flask prior to transfer of the residue and dilute with water to volume Sample solution Transfer 5.0 mL of the Sample stock solution to a 100 volumetric flask add 10 mL of the Cesium chloride solution and 10.0 mL of hydrochloric acid and dilute with water to volume Instrumental conditions See Spectrophotometry and Scattering 851 wavelength Mode Atomic absorption spectrophotometry Analytical Aluminum emission line at 309.3 nm Lamp Aluminum cathode Flame Nitrous acetylene Analysis Samples Aluminum standard solutions solution and Sample Concomitantly determine the absorbance of the solutions Acceptance criteria ABSENCE OF ASBESTOS NMT 2.0 Suppliers of Talc may use one of the following methods to determine the absence of asbestos Proceed as directed for Procedure 1 or Procedure 2. If either test is positive perform Procedure 3 Procedure 1 Infrared Absorption The IR absorption spectrum of a potassium bromide dispersion of Talc at the absorption band at 758 cm using scale expansion may indicate the presence of tremolite or chlorite If the absorption band remains after ignition of the substance at 850 for at least 30 min it indicates the presence of tremolite In the range 600 cm to 650 cm using scale expansion any absorption band or shoulder may indicate the presence of serpentines Procedure 2 Use the following conditions see Ray Diffraction 941 Cu Ka monochromatic 40 kV radiation 24-30 mA the incident slit is set at the detection slit is set at 0.2 the goniometer speed is 10 min the scanning range is -13 20 and -26 20 the sample is not oriented Prepare a random sample and place on the sample holder Pack and smooth its surface with a polished glass microscope slide Record the diffractograms the presence of amphiboles is detected by a diffraction peak at 10.5 0.1 20 and the presence of serpentines is detected by diffraction peaks at 24.3 0.1 20 to 12.1 20 Procedure 3 The presence of asbestos see Optical Mi- range croscopy 776 is shown if there is a of length to width ratios of 20 to 100 or higher for fibers longer than 5 ...mif there is a capability of splitting into very thin fibrils and if there are two or more of the following four criteria 1 parallel fibers occurring in bundles 2 fiber bundles displaying frayed ends 3 fibers in the form of thin needles and 4 matted masses of individ- ual fibers and fibers showing curvature SPECIFIC TESTS MICROBIAL ENUMERATION TESTS 61 and Tests for SpecIFIED MICROORGANISMS 62 Intended for topical administration Total aerobic microbial count NMT 100 cfu Total combined molds and yeasts count NMT 50 cfu g Intended for oral administration Total aerobic microbial count NMT 1000 cfu Total combined molds and yeasts count NMT 100 cfu ACIDITY AND ALKALINITY Boil 2.5 g of Talc with 50 mL of carbon dioxide water under reflux Filter under vac- 2011 The United States Pharmacopeial Convention All Rights Reserved Revision Bulletin Official August 1 2011 Talc 3 uum To 10 mL of the filtrate add 0.1 mL of bromothymol blue TS Add 0.01 N hydrochloric acid until the indicator changes color To a second 10 mL of the filtrate add 0.1 mL of phenolphthalein TS Add 0.01 N sodium hydroxide until the indicator turns pink Acceptance criteria NMT 0.4 mL of 0.01 N hydrochloric acid is required to change the color of the bromothymol blue indicator NMT 0.3 mL of 0.01 N sodium hydroxide is required to change the color of the phenolpthalein indicator to pink LOSS ON IGNITION 733 Sample g Analysis Ignite at 1075 -25 to constant weight Acceptance criteria It loses NMT 7.0 of its weight ADDITIONAL REQUIREMENTS PACKAGING AND STORAGE Preserve in closed con- label tainers No storage requirements specified LABELING The states where applicable that the substance is suitable for oral or topical administration The certificate of analysis states the absence of asbestos It also indicates which method specified in the test for Absence of Asbestos was used for analysis Change to read LABELING The label states where applicable that the substance is suitable for oral or topical administration The certificate of analysis states the absence of asbestos It also indicates that Talc is not derived from deposits that are known to contain associated asbestos and RB 2011 which method specified in the test for Absence of Asbestos was used for analysis * Postponed indefiniteRlBy 2011 2011 The United States Pharmacopeial Convention All Rights Reserved