Objective: To determine equilibrium solubility of Ganoderma triterpenes and its apparent partition coefficients for n-octanol-water/buffer solution systems

and to verify its absorption by in situ perfused rat intestinal model. Method: Ganoderma triterpenes were divided into acidic and neutral triterpenoids. Visible spectrophotometry was established and used to detect their concentration in different pH solvents

and also partition coefficients. The elimination of the percentage of several components in different intestinal segments presume intestinal absorption of triterpenes. Result: The equilibrium solubility of acidic and neutral triterpenoids were less than 100 mg·L-1 in water at 37 ℃

log P were 1.83 and 1.52 respectively. Their oral intestinal absorption were both well

neutral triterpenoids wererelatively better. Conclusion: Ganoderma acidic and neutral triterpenoids both had poor water-solubility

their dissolution was the rate-limiting process of their absorption.