Beta Carotene Capsules
»Beta Carotene Capsules contain not less than 90.0percent and not more than 125.0percent of the labeled amount of C40H56.
Packaging and storage—
Preserve in tight,light-resistant containers.
Identification—
Grind a portion of the Capsule contents,equivalent to about 10mg of beta carotene,transfer to a centrifuge tube,add 5mLof chloroform,shake for 1minute,and centrifuge for 3minutes.Filter the supernatant layer,collecting about 2mLof the filtrate in a 25-mLconical flask.Add 5mLof antimony trichloride TSto the filtrate:a transient purple or blue color forms.
Uniformity of dosage units á905ñ:
meet the requirements.
Assay—
[NOTE—Perform this procedure in subdued light,using low-actinic glassware.]
Cyclohexane—
Spectrophotometric grade,or material that has been purified by being passed through a column of activated silica gel and distilled.
Iodine solution—
Transfer about 10mg of iodine into a 100-mLvolumetric flask.Dissolve in cyclohexane,dilute with cyclohexane to volume,and mix.Dilute 10.0mLof this solution with cyclohexane to 100mL,and mix.Prepare this solution fresh daily.
Assay preparations—
Combine the contents of not fewer than 20Capsules,and grind,using a freezer mill,to a fine powder of uniform color.Transfer an accurately weighed quantity of the finely ground capsule contents,equivalent to about 75mg of beta carotene,to a 1000-mLvolumetric flask,add 500mLof water,and heat at 60
for 15minutes.Cool to ambient temperature,dilute with water to volume,and mix (Assay preparation 1).Transfer 5.0mLof Assay preparation 1to a glass-stoppered,50-mLcentrifuge tube.Add 3g of sodium sulfate decahydrate,2mLof 1Nhydrochloric acid,and 20.0mLof chloroform.Shake by mechanical means for 10minutes,centrifuge for 5minutes,and remove the aqueous layer without disturbing the chloroform layer.Add 2g of anhydrous sodium sulfate to the chloroform layer,shake vigorously,and allow to settle (Assay preparation 2).Transfer 5.0mLof Assay preparation 2to a 50-mLvolumetric flask,add 30mLof cyclohexane,and mix.Add 0.05mLof Iodine solution,dilute with cyclohexane to volume,mix,and allow to stand for 3hours (Assay preparation 3).Transfer 20mLof Assay preparation 3to a centrifuge tube,and centrifuge for 2minutes.
for 15minutes.Cool to ambient temperature,dilute with water to volume,and mix (Assay preparation 1).Transfer 5.0mLof Assay preparation 1to a glass-stoppered,50-mLcentrifuge tube.Add 3g of sodium sulfate decahydrate,2mLof 1Nhydrochloric acid,and 20.0mLof chloroform.Shake by mechanical means for 10minutes,centrifuge for 5minutes,and remove the aqueous layer without disturbing the chloroform layer.Add 2g of anhydrous sodium sulfate to the chloroform layer,shake vigorously,and allow to settle (Assay preparation 2).Transfer 5.0mLof Assay preparation 2to a 50-mLvolumetric flask,add 30mLof cyclohexane,and mix.Add 0.05mLof Iodine solution,dilute with cyclohexane to volume,mix,and allow to stand for 3hours (Assay preparation 3).Transfer 20mLof Assay preparation 3to a centrifuge tube,and centrifuge for 2minutes.
Standard preparations—
Accurately weigh about 17mg of Beta Carotene,previously subjected to the Assayand previously dried in vacuum over phosphorus pentoxide at 40for 4hours,and transfer to a 1000-mLvolumetric flask.Add 10mLof water,heat at 60for 15minutes,and cool to room temperature.Add 3g of sodium sulfate decahydrate and 2mLof 1Nhydrochloric acid,and shake by mechanical means for 10minutes.Add 200mLof chloroform,and shake for 10minutes.Add 750mLof chloroform,shake,and dilute with chloroform to volume,disregarding the aqueous layer (Standard preparation 1).Shake vigorously,and allow the layers to separate completely.Transfer about 20mLof the chloroform layer to a centrifuge tube,add 2g of anhydrous sodium sulfate,shake vigorously,and allow to settle.Transfer 5.0mLto a 50-mLvolumetric flask,add 30mLof cyclohexane,and mix.Add 0.05mLof Iodine solution,dilute with cyclohexane to volume,mix,and allow to stand for 3hours (Standard preparation 2).Transfer about 20mLof Standard preparation 2to a centrifuge tube,and centrifuge for 2minutes.
for 4hours,and transfer to a 1000-mLvolumetric flask.Add 10mLof water,heat at 60for 15minutes,and cool to room temperature.Add 3g of sodium sulfate decahydrate and 2mLof 1Nhydrochloric acid,and shake by mechanical means for 10minutes.Add 200mLof chloroform,and shake for 10minutes.Add 750mLof chloroform,shake,and dilute with chloroform to volume,disregarding the aqueous layer (Standard preparation 1).Shake vigorously,and allow the layers to separate completely.Transfer about 20mLof the chloroform layer to a centrifuge tube,add 2g of anhydrous sodium sulfate,shake vigorously,and allow to settle.Transfer 5.0mLto a 50-mLvolumetric flask,add 30mLof cyclohexane,and mix.Add 0.05mLof Iodine solution,dilute with cyclohexane to volume,mix,and allow to stand for 3hours (Standard preparation 2).Transfer about 20mLof Standard preparation 2to a centrifuge tube,and centrifuge for 2minutes.
Procedure—
Concomitantly measure the absorbances of Assay preparation 3and Standard preparation 2at 452nm,with a suitable spectrophotometer,using cyclohexane as the blank.Calculate the quantity,in mg,of C40H56in the portion of Capsule contents taken by the formula:
40C(AU/AS),
in which Cis the concentration,in µg per mL,of Beta Carotene in the Standard preparation;and AUand ASare the absorbances of Assay preparation 3and Standard preparation 2,respectively.
Auxiliary Information—
Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(DSN)Dietary Supplements:Non-Botanicals
USP28–NF23Page 241
Phone Number:1-301-816-8389