Synthesis and pharmacological evaluation of a new targeted drug carrier system: β-Cyclodextrin coupled to oxytocin

β-Cyclodextrin (β-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 (β-CD-OT) partly preserves the contracting activity of OT (EC50 = 0.40 μM vs 1.7 nM). Moreover, the contraction induced frequency is also lowered by β-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.