Phyto-phospholipid complex of catechin in value added herbal drug delivery

Abstract

Catechin (an anti-inflammatory, antioxidant, antitumour, and hepatoprotective bioflavonoid) is poorly absorbed across the GIT because it has multiple ring molecules that are too large to be absorbed by simple diffusion. It typically has poor miscibility with oils and other lipids which limit their ability to pass across the lipid rich outer membranes of enterocytes of small intestine. Thus catechin–phospholipid complex were prepared to improve its absorption by imparting an environment of improved lipophilicity. The phospholipid complexes of catechin were prepared with phosphatidylcholine in presence of dichloromethane by conventional solvent evaporation technique. Pharmacosomes thus prepared were evaluated for solubility, drug content, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X ray powder diffraction (XRPD), in vitro dissolution study and in vitro antioxidant activity. Prepared phospholipid complex showed high drug content (99.40%. w/w) and improved lipid solubility (0.79–1.97 mg/mL). FTIR, NMR, DSC and XRPD data confirmed the formation of phospholipid complex. Unlike the free catechin, catechin complex showed a sustained release over the 24 h of study. Catechin-phospholipid complex showed slightly better antioxidant activity than that of catechin at all dose levels. Thus it can be concluded that the phospholipid complex of catechin may be of potential use for improving absorption of catechin across the lipidic biological barriers in gastrointestinal tract. It was concluded that the complexation with phospholipids did not interfere with the biological activities. This herbal drug delivery system can pave the way for large molecules to pass through the lipophilic biological membrane (by the virtue of their amphiphilic nature) and get absorbed into the systemic circulation.