title: The use of lipid-based formulations to increase the oral bioavailability of Panax notoginseng saponins following a single oral gavage to rats.
abstract: OBJECTIVE
  This article was intended to improve the absorption of ginsenoside Rg1 and Rb1 of Panax notoginseng saponins (PNS).
  
  
  METHODS
  PNS-Phospholipid complex and a lipid-based formulation by dissolving the complex in the medium chain fattyglycerides were prepared, and their oral relative bioavailability was determined in rats and compared with an aqueous solution of PNS for each component.
  
  
  RESULTS
  The study gave evidence that the phospholipids could combine with the two active constitutes of PNS and form a PNS-phospholipid complex. The complex efficiently increased the solubility of hydrophilic ginsenoside Rg1 and Rb1 in some selected hydrophobic esters, such as fatty glycerides, and constructed the lipid-based formulations of PNS. The experimental result in rats in vivo showed that the oral relative bioavailability was enhanced remarkably by these lipid-based formulations composed of the PNS-Phospholipid complex and various esters. The absorption enhancement of the medium-chain glyceride (Labrafac cc and Capmul MCM (3:1)) was somewhat greater than that of other fatty glyceride. The area under the plasma concentration-time curve (AUC) of ginsenoside Rg1 and Rb1 of the PNS-complex in the medium-chain glyceride were 27.38 microg.mL-1.h and 600.08 microg.mL-1.h, compared with 2.52 microg.mL-1.h and 92.29 microg.mL-1.h of the PNS aqueous solution, respectively.
  
  
  CONCLUSIONS
  The oral relative bioavailability of ginsenoside Rg1 and Rb1 of PNS was enhanced remarkably by the lipid-based formulations. These findings reveal a new strategy to increase oral bioavailability by lipophilicity enhancement for some highly water-soluble but poorly absorbed drugs.
authors.affiliation: Department of Pharmaceutics, China Pharmaceutical University, Nanjing, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xiong
authors.forename: Jianxin
authors.initials: J
authors.lastname: Guo
authors.forename: Luosheng
authors.initials: L
authors.lastname: Huang
authors.forename: Boyu
authors.initials: B
authors.lastname: Meng
authors.forename: Qineng
authors.initials: Q
authors.lastname: Ping
mesh_terms: D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D036145:Ginsenosides / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D053723:Panax notoginseng; D010743:Phospholipids / Q000737:chemistry; D051381:Rats; D012995:Solubility
chemical_list: D036145:Ginsenosides; D010743:Phospholipids; C442759:ginsenoside Rb1; C035054:ginsenoside Rg1