Synthesis and pharmacological evaluation of a new targeted drug carrier system: beta-cyclodextrin coupled to oxytocin.

Beta-cyclodextrin (beta-CD) was monofunctionalized into its carboxylic derivative and then conjugated to the N-side of oxytocin (OT), a nonapeptide involved in human behavior and myometrium contraction. On isolated rat myometrium, this conjugate (beta-CD-OT) partly preserves the contracting activity of OT (EC(50) = 0.40 microM vs 1.7 nM). Moreover, the contraction induced frequency is also lowered by beta-CD-OT. This novel hydrophilic targeted carrier could form a host-guest complex with prostaglandins and their derivatives used as labor inducers or with anticancer drugs used in cervix and endometrial cancer. This strategy can improve the solubility, the stability, and/or the biological activity of these drugs as well as reducing their side-effects.