Hydrophobic lappaconitine loaded into iota-carrageenan by one step self-assembly

• The dynamical degradation by cation exchange resin is simple and practicable.
• LA is simple to self-assemble onto ICG to form pH-sensitivity LA-ICG.
• ICG of low molecular weight has a superior loading capacity of 26.18% (w/w).
• LA-ICG effectively resolves the late onset time and the short duration of LA.

New data on the loading of pH-sensitive lappaconitine loaded into iota-carrageenan (LA-ICG) is provided. This LA-ICG ionic biopolymer was prepared by one step self-assembly. The LA-ICG was characterized in terms of the loading capacity, lappaconitine (LA) releasing behavior, pH-sensitivity, and analgesic properties. Iota-carrageenan (ICG) high loading capacity reached up to 26.18% (w/w). Also, the LA, loaded with ICG, was released faster in an acidic environment than that in neutral or alkaline environments. Animal analgesic experiments showed that the LA-ICG of low molecular weight had earlier onset time and longer duration than the LA. These results suggest that the ICG of low molecular weight has great potential to achieve the synergistic effect of LA. In addition, the ICG can be used as a novel natural polymeric carrier for loading a hydrophobic alkaloid.