title: Phospholipid complex as an approach for bioavailability enhancement of echinacoside.
abstract: BACKGROUND
  Echinacoside (ECH) has been shown to possess a multitude of pharmacological activities, however, oral administered ECH failed to fulfill its therapeutic potential due to poor absorption and low bioavailability. Thus, there is a pressing need to develop a new oral dosage form to enhance its intestinal absorption and improve bioavailability.
  
  
  OBJECTIVE
  The aim of this study was to formulate ECH into phospholipid complex (phytosome, PHY) to enhance intestinal absorption and oral bioavailability of ECH in vivo.
  
  
  METHODS
  The PHY was prepared by a solvent evaporation method and was characterized by differential scanning calorimetry (DSC) and infrared spectroscopy (IR), and then the physicochemical properties, intestinal absorption and bioavailability of the PHY were investigated.
  
  
  RESULTS
  Compared with the physical mixture (MIX) or ECH alone, the n-octanol/water partition coefficient (P) determination results showed that the lipophilicity of ECH was significantly enhanced by formation of PHY. Accordingly, the intestinal absorption rate (Ka) was improved to 2.82-fold and the effective permeability coefficient (Peff) increased to 3.39-fold. The concentrations of ECH in rat plasma at different times after oral administration of PHY were determined by HPLC. Pharmacokinetic parameters of the PHY in rats were Tmax = 1.500 h, Cmax = 3.170 mg/mL, AUC0-∞ = 9.375 mg/L h and AUC0-24 = 7.712 mg/L h, respectively.
  
  
  CONCLUSIONS
  Compared with ECH alone or the MIX group, the relative bioavailability of ECH was increased significantly after formulation into PHY (p < 0.05). This might be mainly due to an improvement of the absorption of PHY.
authors: a State Key Laboratory of Natural Medicines, China Pharmaceutical University , Nanjing , P R China .
authors: Fei
authors: F
authors: Li
authors: b Key Laboratory of Pharmaceutical and Biological Marine Resources Research and Development of Jiangsu Province, Nanjing University of Chinese Medicine , Nanjing , PR China , and.
authors: Xiaolin
authors: X
authors: Yang
authors: c R & D Division, Amphastar Nanjing Pharmaceuticals Inc. , Nanjing , PR China.
authors: Yanan
authors: Y
authors: Yang
authors: a State Key Laboratory of Natural Medicines, China Pharmaceutical University , Nanjing , P R China .
authors: Ping
authors: P
authors: Li
authors: a State Key Laboratory of Natural Medicines, China Pharmaceutical University , Nanjing , P R China .
authors: Zhonglin
authors: Z
authors: Yang
authors: a State Key Laboratory of Natural Medicines, China Pharmaceutical University , Nanjing , P R China .
authors: Chunfeng
authors: C
authors: Zhang
mesh_terms: D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006027:Glycosides / Q000008:administration & dosage* / Q000493:pharmacokinetics; D007408:Intestinal Absorption; D010539:Permeability; D010743:Phospholipids / Q000737:chemistry*; D051381:Rats; D012997:Solvents / Q000737:chemistry; D013055:Spectrophotometry, Infrared
chemical_list: D006027:Glycosides; D010743:Phospholipids; D012997:Solvents; C060297:echinacoside
keywords: Bioavailability; echinacoside; intestinal absorption; phospholipid complex; physicochemical properties