Comparative study of different silymarin formulations: formulation, characterisation and in vitro/in vivo evaluation.

The aim of the present study was to study the synergistic hepatoprotective effect of silymarin with phospholipids when it is encaged in microspheres so as to passively target it to liver and to compare these silymarin formulations with silymarin solution. Various silymarin loaded lipid emulsions were formulated which include formulation A prepared with soyabean oil as an internal oily phase, soya lecithin as surfactant and tween 80 as cosurfactant; formulation B which was same as formulation A but was filtered through 0.45 micro membrane filter and finally steam sterilized for intravenous administration; formulation C containing soyabean oil as an internal oily phase, soya lecithin as surfactant, tween 80 and propylene glycol as cosurfactant/ cosolvent.

Formulation, characterization, and in vitro evaluation of silymarin-loaded lipid microspheres.

The objective of our study was to incorporate and evaluate Silymarin, a chemically defined natural hepatoprotective agent, in lipid microstructured systems. Various constituents of lipid microspheres--namely, internal oily core; surfactant such as soyabean lecithin; and cosurfactants such as span 20, tween 20, tween 80, and propylene glycol--were tried in different concentrations to optimize the final formulation characteristics such as globule size range, structural integrity, sustainability, and percent drug-holding capacity. The final formulation (formulation A) was characterized with respect to size and morphology using transmission electron microscopy and laser diffraction technique.