I have a doctor and have a vast knowledge regarding the epidermis endodermis and hypodermis. The skin can be dry skin where the sebacious glands are not enough while those having the oily skin have more sebacious glands. The skin can be of different types because the scalp skin is different from the skin of the hand . To protect the skin one must use Vitamin A, Vitamin D, Vitamin K, Vitamin E, Citric Acid, Vitamin C, Antioxidants ,beson flour. Tyrosine and lactice acid. I can guide for as a professional for your required job.
Regards
Dr Alam