[Matrix formulation of chaizhi cataplasma optimized by D-optimal mixture design combined with multiple mechanical...

To optimize the matrix formulation of Chaizhi cataplasma (CC) and investigate its release and transdermal absorption properties in vitro. The optimized matrix formulation of cataplasma containing liquid herbal extract is determined by using D-optimal mixture design, with initial bonding strength, endurance bonding strength and gel strength as the evaluating indicators. Modified Franz diffusion cells were used to study the in vitro release and transdermal absorption of geniposide in CC. The optimized matrix formulation of CC contained NP700, aluminum glycinate, tartaric acid, glycerin, PVPK90 and water (9∶0.7∶0.8∶30∶5∶30.5). Cumulative release rate of geniposide in CC was (77.02±3.73)% in 24 h. The percutaneous penetration rate of geniposide was 7.25 μg•cm⁻²•h⁻¹ and the 24 h permeated amount was (156.22±4.90) μg•cm⁻². The optimized CC prepared by the D-optimal mixture design showed a good adhesion and formability. The in vitro release of the geniposide in CC was in accordance with the first order equation, while its in vitro transdermal absorption was close to the zero order equation.