Abstract: A microemulsion composition comprising biphenyldimethyldicarboxylate (BDD) and silybin or a derivative thereof, or a <i>Carduus marianus</i> extract containing silybin and derivatives thereof, as active ingredients; a co-surfactant; a surfactant; and an oil provides a synergistic therapeutic effect for liver diseases due to the complementary work of the two kinds of active ingredients having different working mechanisms without any adverse side effect or an antagonism, and high <i>in vivo</i> bioavailabilities of both of the active ingredients, when orally administered.

Abstract: A microemulsion composition comprising biphenyldimethyldicarboxylate (DDB), a co-surfactant, a surfactant and an oil provides an improved stability and a high in vivo bioavailability of biphenyldimethyldicarboxylate when orally administered.

Abstract: A microemulsion concentrate comprising a water-insoluble anti-cold drug, a surfactant and an oil, which is prepared by a method comprising: (a) dissolving the water-insoluble anti-cold drug in a co-surfactant to obtain a homogeneous drug solution; (b) adding the surfactant and the oil in the drug solution to obtain a microemulsion pre-concentrate; and (c) removing the co-surfactant from the pre-concentrate, contains emulsified drug microparticles which are stable toward pH change and therefore, provides improved bioavaiability of the drug when orally administered.