ABSTRACT
AIM To prepare Guizhi Fuling transdermal patch.METHODS With kinds of pressure-sensitive adhesive and penetration enhancer,kind and consumption of solvent,drug loading as influencing factors,appearance,formability and viscidity of patch,extract dispersion as evaluation indices,single factor test was applied to optimizing the preparation.And subsequent in vitro transdermal absorption test was performed to investigate the steady-state permeation rates of paeoniflorin,cinnamic acid and paeonol onto rat skins.RESULTS The optimal conditions were determined to be Duro-Tak 87-2677 polyacrylate pressure-sensitive adhesive (matrix),1 ∶ 0.5 for ratio of extract to propanediol (solvent),3％ azone as a penetration enhancer,and 20％ for drug loading,the obtained transdermal patch demonstrated both ideal initial adhesion force and holding adhesion force.These three constituents' average transdermal rates were 34.32,1.684,72.90 μg/(cm2 · h) with the average release rates of 26.81,1.523,111.8 μg/(cm2 · h),respectively,whose in vitro transdermal permeation curves conformed to Higuchi equation.CONCLUSION Guizhi Fuling transdermal patch processed with simple and stable preparation technique exhibits good in vitro transdermal permeation performance.
ABSTRACT
In order to investigate trelagliptin succinate's stability in solution, recrystallization and suspension methods in polar solvent (mainly in water and 95% alcohol) were used to study the crystal form transformation of trelagliptin succinate. Single crystal X-ray diffraction, powder X-ray diffraction and thermalgravimetric analysis, and differential scanning calorimetry were used to characterize the structure of the solid state form before and after transformation. The results showed that trelagliptin succinate can easily convert to trelagliptin hemi-succinate mediated by solvent, especially by polar solvent, namely trelagliptin hemi-succinate is more stable than trelagliptin succinate in solution.