In other words, the effective dose of vitamin A is poisoning dose, namely effective dose and poisoning dose is very close. In order to reduce the side effects of vitamin A, improve its effective function, in 1962, researchers do a rial that change vitamin A terminal groups, make it become all trans vitamin A acid, referred to as vitamin A acid or tretinoin.
As a cosmetic raw material, the role of tretinoin is various, and can treat a lot of diseases. For example it can inhibit the epidermal cells hyperkeratosis, cell proliferation, has the antineoplastic effect; Also can restrain sebaceous glands secretion, reduce or remove the skin surface and acne related pathogenic bacteria, in order to reduce acne inflammation reaction; Can fight ageing of the skin, make the skin tender, reduce wrinkles, remove excessive calm pigment; It can inhibit proliferation of skin, regulate immune function. Used in the treatment of acne, chloasma, psoriasis, keratin abnormal sex skin disease, light aging skin, skin cancer and many other diseases.
The use of retinoic acid, common vitamin A acid drugs have oral and external use clinically, such as amine ester. For the oral, because they with side effects, so the requirement of indication is strictly. Usually use in clinical treatment of psoriasis, keratin sexual disease, had better not use for mild acne, only use in moderate to severe acne. Treatment of the disease can oral, also can be for external use. But for senile wart, flat wart, the use of vitamin A acid can be only use for external.
Use such drugs that should be noticed that retinoic acid can increase blood fat, therefore, high blood fat and people with diabetes should be use it carefully, Liver and kidney function person should be banned; Pregnancy and lactation women can not be used, and taking vitamin A acid, should not pregnant after 2 years, because it will led to teratogenic baby; Teenagers under 18 years of age also suggest not to use.
For external use of vitamin A acid use in inflammatory diseases, skin have certain irritation and with the drug concentration and the number of drug in the treatment of the first few weeks will cause varying degrees of skin irritation reaction, such as lupus, desquamation, itching, burning, clinical go up those who say to vitamin A acid reaction. While the skin appear this kind of reaction, you should reduce the number of drug and the dosage, if the reaction is serious, stop using immediately, and to the hospital’s dermatological department to consult the doctors. Vitamin A acid for external use, can produce photosensitization, sun can increase vitamin A acid to hurt skin, so during the day these drugs should not be used, and should be avoid sun exposure. tretinoin cream