Add the following:
»Psyllium Hemicellulose is the alkali soluble fraction of the husk from Plantago ovataForssk.It consists of a combination of highly substituted arabinoxylan polysaccharides.These polysaccharides are linear chains of xylose units (b-(1®4)-xylan)to which are attached single units of arabinose and additional xylose.Rhamnose,galactose,glucose,and rhamnosyluronic acid residues are also present as minor constituents.It contains not less than 75.0percent of dietary soluble fiber,calculated on the dried basis.
Packaging and storage Preserve in tight containers.Store at 25,excursions permitted between 15and 30.
A: The powdered mucilage stains red with ruthenium red TSand lead acetate TS.
B: It meets the requirements of the test for Swell volume.
Total acidity To a beaker,transfer 40mLof the supernatant as obtained below in the test for Swell volume without disturbing the gel.Add 1mLof phenolphthalein TS,and titrate with 0.03Nsodium hydroxide.Not more than 1.8mLis consumed.
Microbial limits á61ñ The total aerobic microbial count does not exceed 1000cfu per g and the total combined molds and yeasts count does not exceed 100cfu per g.It meets the requirements of the tests for absence of Salmonellaspecies and Escherichia coli.
Loss on drying á731ñ Dry at 105for 3hours:it loses not more than 12.0%of its weight.
Total ash á561ñ: not more than 5.0%.
Acid-insoluble ash á561ñ: not more than 1.0%.
Limit of alcohol
Internal standard solution Transfer 5.0mLof n-propyl alcohol into a 500-mLvolumetric flask containing approximately 450mLof water.Dilute with water to volume,insert the stopper into the flask,and mix well.
Standard stock solution Transfer 5.0mLof absolute alcohol at 20±2into a 500-mLvolumetric flask containing approximately 450mLof water.Dilute with water to volume,insert the stopper into the flask,and mix well.
Standard solution Transfer 10.0mLof the Standard stock solutionand 10.0mLof Internal standard solutioninto a 100-mLvolumetric flask.Dilute with water to volume,insert the stopper into the flask,and mix well.
Test solution Transfer 0.5g of Psyllium Hemicellulose,accurately weighed,into a 150-mLconical flask.Add about 90mLof water,insert the stopper into the flask,and stir rapidly for 3hours using a magnetic stirrer.Add 10.0mLof the Internal standard solution,and mix well.Pass the sample through a filter having a 0.45-µm porosity.
Chromatographic system (see Chromatography á621ñ) The gas chromatograph is equipped with a flame-ionization detector and a 0.53-mm ×30-m fused silica analytical column coated with 3.0-µm G43stationary phase.A0.53-mm ×2-m fused silica guard column may be used.The chromatograph is programmed as follows.Initially,the column temperature is equilibrated at 40for 5minutes.The temperature is then increased at a rate of 10per minute to 230,and is maintained at 230for 3minutes.The injection port temperature is maintained at 250,and the detector is maintained at 300.The carrier gas is helium.The split flow ratio is about 10:1,and the flow rate is maintained at about 4.0mLper minute.Inject the Standard solution,and record the peak responses as directed for Procedure:the relative standard deviation for replicate injections is not more than 2%.
Procedure Separately inject equal volumes (about 0.5µL)of the Standard solutionand the Test solution into the chromatograph,record the chromatograms,and measure the responses for all the peaks.Calculate the percentage of alcohol in the portion of Psyllium Hemicellulose taken by the formula:
1000(C/W)(RU/RS),in which Cis the concentration,in mg per mL,of alcohol in the Standard stock solution;Wis the weight,in mg,of Psyllium Hemicellulose taken;and RUand RSare the ratios of the peak responses of alcohol to those of n-propyl alcohol from the Test solutionand the Standard solution,respectively:not more than 12.0%(w/w)is found.
Organic volatile impurities,Method IVá467ñ: meets the requirements.
Heavy metals,Method IIá231ñ: 10µg per g.
Swell volume Add 0.50g of Psyllium Hemicellulose to a glass-stoppered,100-mLgraduated mixing cylinder.To avoid material clumping,hold the cylinder at a 45angle,and gently rotate it while using a wash bottle to forcefully add about 30mLof water.Add water to bring the total volume to 100mL,and cap the cylinder.Invert the cylinder several times until a uniform suspension is achieved,and allow to stand.Gently invert the cylinder several times again at 4hours and 8hours after the initial sample preparation,and allow to stand.Allow the gel to settle for 16hours.Determine the volume of the gel:not less than 80mLper g of Psyllium Hemicellulose is found.
Content of soluble dietary fiber
Alcohol solution Transfer 82.0mLof alcohol to a 100-mLvolumetric flask,dilute with water to volume,and mix.
Buffer solution Dissolve 1.95g of 2-(N-morpholino)-ethanesulfonic acid and 1.22g of tris(hydroxymethyl)aminomethane in 170mLof water.Adjust with 6Nsodium hydroxide to a pHof 8.2,dilute with water to 200mL,and mix.[NOTEIt is important to adjust the pHto 8.2at 24.If the Buffer solutiontemperature is 20,adjust the pHto 8.3;if the temperature is 28,adjust the pHto 8.1.For deviations between 20and 28,adjust by interpolation.]
Acid solution Prepare 0.561Nhydrochloric acid by dissolving 9.35mLof 6Nhydrochloric acid in 70mLof water.Dilute with water to 100.0mL,and mix.
Phosphate buffer Prepare a pH6.0phosphate buffer (see Buffer Solutionsunder Reagents,Indicators,and Solutions).
Protease solution Dissolve 5mg of protease in 0.1mLof Phosphate buffer.
Enzyme purity To ensure the absence of undesirable enzymatic activities and the presence of desirable enzymatic activities,proceed as directed for Test preparations and Procedure using the substrates listed in the following table in place of Psyllium Hemicellulose.
Blank preparations Using two 400-mLtall-form beakers,appropriately labeled,proceed as directed for Procedurewithout Psyllium Hemicellulose.
Test preparations Weigh accurately,in duplicate,approximately 0.2g of Psyllium Hemicellulose,previously milled to very fine powder.[NOTEDuplicates should differ by less than 1mg in weight.]Transfer duplicate samples to appropriately labeled 400-mL,tall-form beakers,and proceed as directed for Procedure.
Procedure Treat each preparation in the following manner.Add 40mLof Buffer solutionto the beaker.[NOTEFor the Test preparation,stir until Psyllium Hemicellulose is completely dispersed.]Add 125µLof heat-stable a-amylase solution,and stir to ensure uniform mixing.Cover the beaker with aluminum foil,and incubate over a water bath maintained at 95to 100for 15minutes,with continuous agitation.[NOTEStart timing once the water bath temperature reaches 95;a total time of 35minutes is usually sufficient.]Remove the beaker from the water bath,and cool to 60.Remove the aluminum foil,scrape any ring from inside the beaker,and disperse any gels in the bottom of the beaker with a spatula.Rinse the walls of the beaker and the spatula with 10mLof water,collecting the rinsings in the beaker.Add 500µLof Protease solution.Cover with aluminum foil,and incubate over a water bath maintained at 60±3for 30minutes with continuous agitation.[NOTEStart timing when the bath temperature reaches 60.]Remove the foil,and transfer 5mLof Acid solution while stirring.Adjust,if necessary,with 1Nsodium hydroxide or 1Nhydrochloric acid to a pHof 4.28±0.07at 60.[NOTEIt is important to adjust the pHto 4.28while the solution in the beaker is maintained at 60,otherwise the pHwill increase at lower temperatures.]Add 150µLof amyloglucosidase solution while stirring.Cover with aluminum foil,and incubate over a water bath maintained at 60±3for 30minutes with constant agitation.[NOTEStart timing once the water bath reaches 60.]Transfer approximately 40mLof the beaker contents to a 50-mLcentrifuge tube,and sonicate the tube contents for 3minutes.*Centrifuge at 10,00014,000rpm for 10minutes.Carefully pour the supernatant into an appropriately labeled 600-mLtared beaker.Do not disturb any pellet in the bottom of the centrifuge tube.Add the remaining sample from the original 400-mLbeaker into the centrifuge tube still containing the pellet.Rinse the 400-mLbeaker with 1520mLof water,and add the rinsing to the 50-mLcentrifuge tube.Centrifuge the sample at 10,00014,000rpm for 10minutes.Carefully pour the supernatant into the 600-mLbeaker containing the first supernatant.Add 390mL(measured before heating)of alcohol at 60to the 600-mLbeaker.Cover the beaker,and allow to stand for at least 1hour to form a precipitate.
Place 3g of chromatographic siliceous earth into a clean air-dried crucible with a fritted disk.Heat the crucible containing chromatographic siliceous earth at 525ºin a muffle furnace for at least 4hours.Cool.Pass deionized water through the crucible while applying constant suction.Rinse with acetone,and allow to air-dry.Store the crucible in a convection oven at approximately 130ºfor at least 2hours before use.Weigh the prepared crucible to 0.1mg before use.Wet the chromatographic siliceous earth in the crucible using a stream of Alcohol solution from a washing bottle,and apply suction to evenly distribute the chromatographic siliceous earth over the fritted disk.Maintaining the suction,transfer the supernatant and precipitate from the beaker to the crucible,and filter.Transfer any solid residue in the beaker with the aid of Alcohol solution.[NOTEIn some cases,gums may form during filtration,trapping liquid in the residue.If so,break the surface film with a spatula to improve filtration.]Wash the residue in the crucible sequentially with 30mLof Alcohol solution,20mLof alcohol,and 20mLof acetone.Dry the crucible containing the residue at 100in a convection oven for at least 4hours,cool to room temperature in a desiccator.
Determine the weight of the residue (R).
Use one of the duplicate residues from the Test preparationsand one of the blank residues from the Blank preparationsto determine the protein content,in mg,by placing the residue in a 500-mL Kjeldahl flask,and proceeding as directed for Method IunderNitrogen Determination á461ñ.The protein content is determined by multiplying the content of nitrogen found by 6.25.Incinerate the residue from the remaining duplicate of the Test preparationand the Blank preparationas directed for Total Ashunder Articles of Botanical Origin á561ñat a reduced temperature of 525,and determine the ash content as directed.Calculate the corrected average weight of the blank,in mg,B,by the formula:
in which RBis the weight,in mg,of the average blank residue for duplicate blank determinations;PBis the content,in mg,of protein found in the blank;and ABis the content,in mg,of ash found in the blank.Calculate the content of soluble dietary fiber,in percentage,by the formula:
in which RUis the weight,in mg,of average residue for the duplicate Test preparations;PUis the content of protein,in mg,found in the Psyllium Hemicellulose;AUis the content of ash,in mg,found in the Psyllium Hemicellulose;Bis the average weight of the blank as calculated above;and WUis the average weight,in mg,of the Psyllium Hemicellulose taken.USP28
* Asuitable sonicator is Sonifier 250(or equivalent),equipped with a 12-mm tip,from Branson Ultrasonic Corp.,Danbury,CT,in which an output control value of 3and a cycle time of 75%generates a power output of 43W.
Auxiliary Information Staff Liaison:Gabriel I.Giancaspro,Ph.D.,Senior Scientist and Latin American Specialist
Expert Committee:(DSB)Dietary Supplements:Botanicals
USP28NF23Page 1675Pharmacopeial Forum:Volume No.30(1)Page 173