Ethylenediamine Salt Enhances the Solubility and Dissolution of Flurbiprofen

Abstract Drugs that are poorly soluble in water are difficult to absorb orally, resulting in low bioavailability. Flurbiprofen (FLU) is an arylpropionic acid nonsteroidal anti‐inflammatory drug belonging to BCS class II, with low water solubility. In this study, a novel flurbiprofen‐ethylenediamine salt (FLU‐EDA) was successfully prepared via solvent crystallization. Its crystal structure was determined via single‐crystal X‐ray diffraction (SXRD). Further, the physicochemical properties of FLU‐EDA salt were characterized by powder X‐ray diffraction (PXRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FT‐IR). The solubility and intrinsic dissolution rate (IDR) of FLU‐EDA salt in water were investigated. The results showed that compared with FLU, the solubility and IDR of FLU‐EDA salt increased by 57‐fold and 32‐fold, respectively. This indicates that FLU‐EDA salt can significantly enhance the solubility and dissolution rate of flurbiprofen in water. This study provides basic data and theory for the development of new formulations of flurbiprofen.