Complexation of Vinpocetine with Cyclodextrins in the Presence or Absence of Polymers.Binary and Ternary Complexes Preparation and Characterization

摘要

Inclusion complexation between deta-cyclodextrin (deta-CD),hydroxypropyl-deta-cyclodextrin(HP-deta-CD),water-soluble poly-mers(PVP and HPMC)and vinpocetine was studied in aqueous solution and in the solidstate.Phase solubility studies were used to evaluate the complexation in aqueous solution at room temperature.Stability constants (K_c)of binary and ternary complexes were determined spectrophotometrically.Differential scanning calorimetry (DSC)was used to char-acterixe kneaded,co-evaporated and lyophilised binary and ternary systems.The K_c values obtained were 70.14 M~-1 and 35.01 M~-1 for vinpocetine-beta-CD and vinpocetine-HP-beta-CD and increased in a qange of 17% to 94% by addition of water-soluble polymers.Some preliminary evidences of inclusion complexation were obtained from DSC suggesting that co-evaporated and lyophilised binary and ternary systems were truly inclusion complexes.