Hydroxypropyl β cyclodextrins effects on self-assembly of cyclic peptide, lanreotide acetate, in water and subsequent release rate from an in vitro emulator of subcutaneous delivery.

Most of the peptide drugs are often delivered subcutaneously. The significant barrier in this type of peptide administration is the high concentration of formulation, which can lead to self-assembly and aggregation. These phenomena can negatively impact the peptide drug's bioavailability, manufacturing, and injectability. This study investigated the self-assembly behavior of Lanreotide acetate at high concentrations in water using Hydroxypropyl β- Cyclodextrins (HPβCyD) to mitigate the self-assembly and enhance release rate during subcutaneous administration. Our finding demonstrated that the lanreotide/ HPβCyD inclusion complex effectively prevents aromatic-aromatic interactions of lanreotide, thereby controlling self-assembly. This complexation also alters the viscosity behavior of lanreotide from non-Newtonian under low shear rates to Newtonian solution. Furthermore, the lanreotide/ HPβCyD inclusion complex reduces interactions with hyaluronic acid in the subcutaneous environment, leading to significant improvement in the release rate of lanreotide acetate at high concentrations (above 3 % w/w in water).