Preparation and property evaluation of vitamin A cyclodextrin inclusion complex

Hydroxypropyl-β-cyclodextrin (HP-β-CD) is widely used in drug encapsulation and cosolvent of insoluble drugs, modified HP-β-CD derivatives may to make pH sensitive by introducing functional groups. In this study, HP-β-CD derivative was prepared by oxidation cross-linking method with urea as the crosslinker agent. HP-β-CD derivatives and vitamin A (VA) inclusion complex were characterized using FT-IR, DSC, XRD and SEM. The solubilization effect, encapsulation efficiency (EE, %), loading content (LC, %) and in vitro release behavior of cyclodextrin derivatives on VA also investigated at different pH. The experimental results show that urea linked HP-β-CD can significantly increase the solubility of VA up to 32 times then pure water, the EE of the VA inclusion complex reach 66.88±4.56%, and the LC was 15.38±1.12%, The 24h in vitro cumulative release reaches 95.91%(pH=4.5) and 66.68%(pH=7.0) when the ratio of urea to HP-β-CD was 3:1. The HP-β-CD derivatives can increase the solubility of VA and the drug release has pH sensitivity