Utilization of diethyl-beta-cyclodextrin as a sustained-release carrier for isosorbide dinitrate

Heptakis(2,6-di-O-ethyl)-beta-cyclodextrin (2) was prepared and its physicochemical properties, such as aqueous solubility and surface activity, were compared with those of beta-cyclodextrin (1) and heptakis(2,6-di-O-methyl)-beta-cyclodextrin (3). A possible utility of 2 as a sustained-release drug carrier was examined using a water-soluble drug, isosorbide dinitrate. The dissolution and release rates of isosorbide dinitrate from capsule and tablet forms were significantly retarded by the complexation with 2. The sustained-release pattern of isosorbide dinitrate was produced for a long period after the oral administration of a single dose of capsule or tablet containing the 2 complex to rats. The results indicated that 2 may serve as a hydrophobic drug carrier for sustained-release of isosorbide dinitrate.