Lubricating oil was first used for the examination of human body in clinical medicine. Many medical devices will cause different degrees of mechanical damage when they go deep into the human body, and lubricating oil can minimize the damage to body tissues and mucous membranes.
The main component of early human lubricating oil was glycerol and hydrophilic substances, and after improvement, sodium hyaluronate, ethyl cellulose, carbomer and other components were added. After improvement, the viscosity is reduced, the pH value is balanced, which makes it as close as possible to human body fluids, and the incidence of allergic symptoms is reduced.