ABSTRACT
Objective: To investigate the effects of common peneration enhancers on the transdermal permeation of total flavones and six flavonoid components from Scutellariae Radix Gel-unguentum (SRGU), thus to provide the experimental evidence for the selection of optimal penetration enhancers. Methods: In vitro diffusion cell method was used to evaluate the changes of the transdermal pemeation parameters by azone (AZ), menthol (MT), and propylene glycol (PG), separately or in combination. Results: When applied individually, AZ and MT showed the best enhancing effect on the transdermal permeability and cumulative permeation of flavonoids and their aglycons, respectively. PG, in contrast, produced poor enhancement. When applied in combination, the permeation enhancing effects were generally more remarkable than those of single enhancer. In particular, 3% AZ + 5% PG could achieve the most effective enhancement effect on the transdermal permeation of flavonoids. Conclusion: Penetration enhancers could significantly affect the transdermal permeation of total flavones and flavonoid components from SRGU in vitro, and 3% AZ + 5% PG may serve as the most effective enhancer.