1、Improper handling of all vitamin A derivatives can lead to decomposition.

2、Correct operating procedures:

（1）Low-temperature handling (where possible, inert gas protection should be used).

（2）Light-avoidance operation.

3、Comparative stability of vitamin A derivatives:

Retinoic acid > Retinyl esters (HPR stable) > Retinol, Retinal.

4、Recommendations for the use of vitamin A derivatives in cosmetics:

（1）Suitable for serums, lotions, creams, and emulsified products, as well as oily formulations.

（2）Suggested formulation with antioxidants and photostabilizers.

（3）It is advised to use packaging materials that are dark and light-protected, and sealed.

（4）Storing the finished product in a cool, dry place at low temperatures is more conducive to maintaining its effectiveness and activity.