The properties are basically the same as glycerin, but the viscosity, toxicity and irritation are less than glycerin. It has good solubility and can dissolve many drugs such as sulfonamides, local anesthetics, vitamin A, vitamin D, sex hormones, chloramphenicol and many volatile oils. in, but also immiscible with fatty oils.
A certain proportion of the mixture of propylene glycol and water can delay the hydrolysis of some drugs and increase their stability. When its concentration is selected appropriately, it can be used as a vehicle for injection and has quick-acting or delayed-acting effects. A certain concentration of propylene glycol can still be used as a penetration enhancer for drug absorption through the skin or mucous membranes.