To improve the bioavailability or absorption of poorly lipid soluble drug, due to which herbal active constituent can cross the lipid membrane, and they show better absorption by combining with phosphatidylcholine. By combining herbal active constituent with phosphatidylcholine the absorption of phytosome is increased. Most of the biologically active components of herbal drugs are water soluble e.g. flavonoids. terpenoids etc. However, these are poorly absorbed due to their large molecular size range (limited/no passive diffusion) or due to poor permeability through the lipid membranes resulting in poor bioavailability. Some herbal components in extracts get destroyed in gastric environment, led to low bioavailability thereby limiting the clinical utility of these plant extracts. Complexation with some clinically useful nutrients such as phospholipids substantially improves the bioavailability of these active components. So these water soluble components could be converted into the lipid compatible complexes by using the phospholipids from soy, mainly phosphotidylcholine. These are called as Phytosome and can easily cross the lipid membranes. Phytosome led to enhanced solubility of the poorly lipid soluble drugs and increase in the bioavailability was reported due to increased absorption in the GIT. A number of methods have been reported for preparation of the Phytosome. In phytosome, the complexation of phospholipids and water soluble active plant components involve chemical bond formation and therefore more stable. Whereas in liposome"s no chemical bond is formed. phosphatidylcholine molecules simply surround the water soluble components. Phospholipids are also employed as natural digestive aids and carriers for water soluble and lipid soluble nutrients. Due to improved absorption characteristics, phytosome are more bioavailabie than conventional herbal extracts of withaferin. Therefore It is worthwhile to form complex of phosphatidylcholine with active constituen
