Peracylated beta-cyclodextrins as novel sustained-release carriers for a water-soluble drug, molsidomine

Peracylated beta-cyclodextrins with different alkyl chains (acetyl-octanoyl) were prepared by acylating all hydroxyl groups of beta-cyclodextrin (beta-CyD), and their physical properties were evaluated. These hydrophobic beta-CyDs decreased the release rate of molsidomine, a peripheral vasodilator, in proportion to the lengthening of alkyl chain and suppressed a peak plasma level of molsidomine following oral administration of peracylated beta-CyD complexes to dogs. Among the peracylated beta-CyDs tested, perbutanoyl-beta-CyD maintained sufficient plasma drug levels for a long period of time, while other peracylated beta-CyDs having shorter or longer chains were inappropriate to control the in-vivo release behaviour of molsidomine. The prominent retarding effect of perbutanoyl-beta-CyD was ascribable to the appropriate mucoadhesive property and hydrophobicity, compared with other peracylated beta-CyDs. The present results suggest that perbutanoyl-beta-CyD is particularly useful in modifying the release rate of water-soluble drugs as a novel slow-release carrier.