Preparation and quality evaluation of 7-ethyl-10-hydroxycamptothecin (SN38) nanocrystalline liposomes and evaluation of anti-breast cancer effects in vivo and in vitro.

SN38 has strong anti-tumor activity. However, issues such as its limited solubility and stability have restricted its development and application. To address these problems, we designed a formulation of SN38 nanocrystals encapsulated in liposomes (SN38-NC@Lipo), aiming to enhance the stability, permeability and anti-breast cancer efficacy of the drug. SN38-NC was prepared by reversolvent-ultrasound method and SN38-NC@Lipo by ethanol injection. The Box-Behnken response surface optimization method was used to determine and characterize SN38-NC@Lipo. The uptake of these nanoparticles by 4 T1 cells and its effect on cell apoptosis were studied. In vivo pharmacodynamic evaluation was conducted using 4 T1 cells to assess the anti-breast cancer effect of nanomedicines. Measure the body weight and tumor volume, calculate the tumor suppression rate, observe the pathological changes of the tumor, and detect the blood routine indicators. SN38-NC with a particle size of 196.4 ± 0.197 nm and a PDI of 0.174 ± 0.009, and SN38-NC@Lipo with a particle size of 177.5 ± 4.124 nm, a PDI of 0.328 ± 0.019, an encapsulation rate of 91.32 %±1.77, and a drug load of 6.88 %±0.13 were successfully prepared. In vivo pharmacodynamics showed significant anti-breast cancer effects on 4 T1 cells for SN38-NC@Lipo, SN38-NC, and SN38. The tumor inhibitory rate for the SN38-NC@Lipo group was 70.34 %, higher than the 61.45 % for the SN38-NC group and 45.73 % for the SN38 group. SN38-NC and SN38-NC@Lipo were prepared with small particle size and low PDI. SN38-NC@Lipo showed excellent drug loading and encapsulation rates. Both formulations exhibited enhanced anti-breast cancer effects in vivo and in vitro.