Emodin–phospholipid complexA potential of herbal drug in the novel drug delivery system

Developing the drugs as amphiphilic lipid complexes is a potential approach for improving therapeutic efficacy of the drugs by increasing solubility, reducing drug crystallinity, modifying dissolution behavior (sustained or controlled release), and improving bioavailability. Emodin (1,3,8-trihydroxy-6-methylanthraquinone), an anthranoid derivative, shows several biological effects like antimicrobial, antidiuretic, anti-cancerous, and potent antioxidant but due to poor solubility, the dissolution restrains its valuable importance. To overcome this limitation, the emodin–phospholipid complex was developed and investigated by thermal analysis (differential scanning calorimetry), crystallographic (X-ray diffractography), surface morphology (scanning electron microscopy), spectroscopic methods (FT-IR, 1H-NMR), solubility, and the dissolution (in vitro drug release) study. The phospholipid complex of emodin was found, fluffy and porous with rough surface morphology in the SEM. FT-IR, 1H-NMR, DSC, and X-RPD data confirmed the formation of the complex. The water and n-octanol solubility of emodin was improved from 2.25 to 9.97 and 53.45 to 77.62 μg/ml, respectively, in the prepared complex. The improved dissolution was shown by the phospholipid complex. Based on the results of the study, it can be concluded that the phospholipid complex may be considered as promising drug delivery system for improving the overall absorption and bioavailability of the emodin molecule.