Chenodeoxycholic Acid (CDCA) is a 7-position differential isomer of ursodeoxycholic acid. Ursodeoxycholic acid can be oxidized with chenodeoxycholic acid 5β-3α-hydroxy-7-carbonyl cholic acid (7K-LCA), and then reduced to synthesis, so that bear  bile contains deoxycholic acid for ursodeoxycholic acid. At the same time can also use cattle, pigs, sheep and other animal cholic acid as raw material synthesis ursodeoxycholic acid. Liu Xiangyun et al reported that the chicken bile by degreasing pretreatment, with bile salt precipitation method to remove the bile pigment and other impurities, the alkaline hydrolysis, concentrated acid precipitation, washing, drying, column chromatography separation of pure chenodeoxycholic acid.
Bear bile chemical composition is more complex, including bile acids, cholesterol, bile pigment, amino acids, as well as trace elements. Bile acids contain cholic acid (CA), chenodeoxycholic acid (CDCA), ursodeoxycholic acid (UDCA), deoxycholic acid (DCA), taurine ursodeoxycholic acid (TUDCA), taurine (TCD2CA), etc., in which ursodeoxycholic acid (UxA) is 3α, 7β-dihydroxy 25β-chrome acid is the main component of traditional Chinese medicine bear bile.