Which vitamin a derivative is used to treat acne vulgaris by reducing sebum formation and secretion as well as exerting antiinflammatory and anti-keratolytic effects?

The answer would be: Isotretinoin

Isotretinoin is vitamin A derivative that has an effect on the skin. It will reduce sebum formation and secretion, so it will reduce the risk to form another acne. The anti-inflammatory will effect will reduce acne swelling and pain. The anti keratolytic effect will normalize the skin growth.