Packaging and storage—
Preserve in tight containers, preferably under an atmosphere of an inert gas, protected from light.
Labeling—
Label it to indicate the form in which the vitamin is present, and to indicate the presence of any antimicrobial agent, dispersant, antioxidant, or other added substance, and to indicate the vitamin A activity in terms of the equivalent amount of retinol, in mg per g. The vitamin A activity may be stated also in USP Units, on the basis that 1 USP Vitamin A Unit equals the biological activity of 0.3 µg of the all-trans isomer of retinol.
Identification—
A:
To 1 mL of a chloroform solution of it containing the equivalent of approximately 6 µg of retinol, add 10 mL of
antimony trichloride TS: a transient blue color appears at once.
B: Thin-Layer Chromatographic Identification Test 
201
—
Test solution—
FOR LIQUID FORM OF VITAMIN A—
Dissolve a volume equivalent to about 15,000 USP Units in chloroform to obtain 10 mL of solution.
FOR SOLID FORM OF VITAMIN A—
Weigh a quantity equivalent to about 15,000 USP Units, place in a separator, add 75 mL of water, shake vigorously for 1 minute, extract with 10 mL of chloroform by shaking for 1 minute, and centrifuge to clarify the chloroform extract.
Standard solution—
Dissolve the contents of 1 ampul of
USP Vitamin A RS in chloroform to obtain 25.0 mL.
Developing solvent system:
a mixture of cyclohexane and ether (4:1).
Procedure—
Apply at the starting point of the chromatogram 0.015 mL of the
Standard solution and 0.01 mL of the
Test solution, and proceed as directed for
Thin-Layer Chromatography under Chromatography 621. Allow the solvent front to move a distance of 10 cm, remove the plate, and air-dry. Spray with
phosphomolybdic acid TS: the blue-green spot formed is indicative of the presence of retinol. The approximate
RF values of the predominant spots, corresponding to the different forms of retinol, are 0.1 for the alcohol form, 0.45 for the acetate, and 0.7 for the palmitate.
Absorbance ratio—
The ratio of the corrected absorbance (
A325) to the observed absorbance
A325 determined as directed under
Vitamin A Assay 571 is not less than 0.85.
Assay—
Using a suitable quantity of Vitamin A, accurately weighed, proceed as directed under
Vitamin A Assay 571.
Auxiliary Information—
Staff Liaison :
Lawrence Evans, III, Ph.D., Scientist
Expert Committee : (DSN05) Dietary Supplements - Non-Botanicals
USP29–NF24 Page 2258
Pharmacopeial Forum : Volume No. 29(6) Page 2004
Phone Number : 1-301-816-8389
