» Vitamin A contains a suitable form of retinol (C20H30O; vitamin A alcohol) and possesses vitamin A activity equivalent to not less than 95.0 percent of that declared on the label. It may consist of retinol or esters of retinol formed from edible fatty acids, principally acetic and palmitic acids. It may be diluted with edible oils; or it may be incorporated in solid, edible carriers or excipients; and it may contain suitable antimicrobial agents, dispersants, and antioxidants.
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.
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
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 Please check for your question in the FAQs before contacting USP.Chromatographic Column
USP32NF27 Page 3865Pharmacopeial Forum: Volume No. 29(6) Page 2004
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.