Procaine hydrochloride is a topical anesthetic, which can block the nerve fiber conduction temporarilyand has a narcotic effect,strong effect, low toxicity, and non-addictive, but on the skin, mucosal penetration is weak, unsuitable for surface anesthesia, patients are used for infiltration, conduction and spinal anesthesia. 

White fine needle crystal or crystalline powder at room temperature, no smell, taste slightly bitter and Ma, soluble in water, soluble in ethanol, almost insoluble in ether. Procaine hydrochloride ester bond structure can be hydrolyzed to produce amino acid and diethylaminoethanol, under certain conditions, the amino acid may be further decarboxylated toxic.

The structure of procaine hydrochloride with aromatic primary amino, easy oxidation discoloration pH, temperature, UV, oxygen and metal ions can accelerate the oxidation discoloration. The aqueous solution was stable in pH3.0~5. So preparation of procaine hydrochloride injection, it generally takes add acid to regulate pH 3.3 to 5.5, and strictly control the sterilization temperature and time. to 100 ºC steam sterilization 30min circulation is appropriate, and should pay attention to shading, sealed save. 

The product structure of aromatic primary amino group in dilute can generate diazonium salt, coupling reaction occurs when add alkaline β-naphthol, generating azo compounds scarlet.