DropBrigt®4BR (4-butylresorcinol) has a potent inhibitory effect on tyrosinase activity. On the one hand, it can bind to the double copper ion of tyrosinase, the active site of tyrosinase, which competitively inhibits tyrosinase.

On the other hand, melanin also has excellent antioxidant properties, and the first two steps of melanin formation are oxidation processes. Antioxidant and competitive inhibition are the most common and important mechanisms for freckle whitening, and DropBright®4BR possesses both of these effects. In all three stages of melanin synthesis, DropBright®4BR not only exhibits a significant inhibitory effect on tyrosinase activity, but also has a synergistic effect in whitening activity. DropBright®4BR is a highly effective skin whitening agent.

• Before melanin synthesis, it inhibits tyrosinase synthesis and glycosylation, preventing the enzyme from being absorbed into melanosomes.
• Inhibition of enzyme activity that acts as a competitive inhibitor of tyrosinase and TRP1 enzymes during melanin synthesis reduces the production of melanin-specific byproducts.
• After melanin synthesis, tyrosinase increases the breakdown of melanocytes, inhibiting keratinocyte migration and acting as a fatty acid photo-removal agent. This function is enhanced by the presence of fatty acids, which regulate tyrosinase breakdown.