Preparation and characterization of mucoadhesive enteric-coating ginsenoside-loaded microparticles

Ginsenoside saponins are phytochemically extracted from red ginseng and have been regarded as the principal components manifesting the pharmacologic activities. Saponins are very soluble in water but poorly absorbed when orally administrated. Moreover, they have some disadvantages including the decomposition in acid medium. The aim of this study was to develop oral formulation of ginsenosides composed of enteric-coating polymer and mucoadhesive polymer considering the low stability in acid medium and the low permeability of saponins. Ginsenoside-loaded microparticles were prepared by spray dryer. The influences of various parameters such as the ratio of saponin to polymer, feed concentration, feed rate, inlet/outlet temperature and additional excipients during spray-drying were investigated. In vitro release profile of ginsenoside-loaded microparticles using additional excipients, ginsenoside saponin Rg1 or Rb1 showed an 18 or 13% release in pH 1.2 when ethyl cellulose was added. Also, ginsenoside-loaded microparticles exhibited mucoadhesive properties in the presence of chitosan. The application of these polymers is being considered as the potential strategy for improvement of bioavailability in saponin delivery, orally.