Chemical Properties
Hyaluronidase, an enzyme extracted from mammalian testes that hydrolyzes vitreous mucopolysaccharides, is a white or slightly yellow powder that is readily soluble in water but insoluble in ethanol, acetone, or ether. It is odorless and relatively stable, exhibiting no loss of activity after continuous heating at 420°C for 60 minutes and retaining 80% of its activity after continuous heating at 1000°C for 5 minutes. It is easily inactivated in low-concentration aqueous solutions and can generally be protected with gelatin or gum arabic. Fe2+ and Cu2+ ions reversibly inhibit the enzyme. Pb2+, Hg2+, Ni2+, and other ions have no significant effect on enzyme activity. The inhibitory effects of chondroitin sulfate B (dermatan), heparan sulfate, keratan sulfate, sodium heparin, and high-concentration hyaluronic acid on hyaluronidase can be reversed in the presence of sodium chloride (0.15 mol/L) or protamine sulfate. Hyaluronidase injection is a sterile freeze-dried product of hyaluronidase and appropriate excipients. It appears as a white or off-white freeze-dried block or powder. Aqueous solutions are unstable and must be prepared immediately before use.
