Vitamin A (Retinol)
Purified vitamin A is a viscous yellowish oil. It is freely soluble in most organic solvents such as methanol, ether, acetone, chloroform and petroleum ether as well as in fatty oils like olive, sesame and groundnut. However, Vitamin A is insoluble in water. It is highly susceptible to the action of atmospheric oxygen and oxygen carriers, further to oxidizing agents and metal ions. Vitamin A is also rapidly destroyed by UV light. Even in diffuse day light, the vitamin A conten of solutions is markedly reduced within a few hours. You must remember that vitamin A should be stored in a cool place, protected from light under vacuum or inert gas in air-tight containers or sealed ampules. You must understand that vitamin A itself is very unstable against external influences.