The farnesoid X receptor (FXR), also known as the bile acid receptor (BAR) or NR1H4, is a member of the nuclear receptor superfamily of ligand-activated transcription factors. FXR forms with retinoid X receptor (RXR) a heterodimer receptor crucial for bile acid homeostasis. FXR is expressed in various tissues including the liver, kidney, intestine, colon, ovary, and adrenal gland, and is activated by a variety of naturally occurring bile acids, including the primary bile acid chenodeoxycholic acid (CDCA) and its taurine and glycine conjugates. Upon activation, the FXR-RXR heterodimer binds the promoter region of target genes and regulates their expression.
6-Ethyl-chenodeoxycholic acid (6-ECDCA, or obeticholic acid, or OCA), a bile acid derivative, shows a potent FXR activating activity, and accordingly offers great promise for the treatment of FXR-mediated diseases or conditions. Thus, there is a need to develop obeticholic acid compositions having desirable dissolution profile and solubility, and possessing advantageous storage stability.