Abstract

The active substance used in this study is a Milk thistle dry extract, refined and standardized (equiv. to 45 mg/90 mg Silymarin as Silibinin). The main problem with milk thistle extract (silymarin) is its poor oral bioavailability, which is attributable to its low water solubility and low permeability as well as degradation in the gastrointestinal tract. The purpose of this work was to evaluate and compare the effect of some surfactants and various sugars like lactose, sorbitol and mannitol as carriers for improvements of solubility and/or dissolution of poor aqueous soluble drug, milk thistle extract (Silymarin) from formulated capsules. The formulation containing combination of Sodium lauryl sulfate, Polysorbate 80 as solubilizers and mannitol as a diluent exhibits best rheologic characteristics and highest dissolution rate of the Milk thistle dry extract (Silymarin).