Orally delivered solid lipid nanoparticles of irinotecan coupled with chitosan surface modification to treat colon cancer: Preparation, in-vitro and in-vivo evaluations.

Irinotecan-loaded solid lipid nanoparticles (IRI-SLNs) was formulated and tested for its potential activity against colon cancer. IRI-SLNs were prepared by applying the principles of DoE. Nanoparticles were further surface modified using chitosan. Characterizations such as size, poly-dispersity, surface charge, morphology, entrapment, drug release pattern, cytotoxicity were conducted. In-vivo studies in male Wistar rats were carried to ascertain distribution pattern of SLNs and their acute toxicity on various vital organs. Lastly, stability of the SLNs were evaluated. Particles had a size, polydispersity and zeta potential of 430.77 ± 8.69 nm, 0.36 ± 0.02 and -40.06 ± 0.61 mV, respectively. Entrapment of IRI was 62.24 ± 2.90% in IRI-SLNs. Sustained drug release was achieved at a colonic pH and long-term stability of NPs was seen. Cytotoxicity assay results showed that SLNs exhibited toxicity on HCT-116 cells. Biodistribution studies confirmed higher concentration of drug in the colon after surface modification. An acute toxicity study conducted for 7 days showed no severe toxic effects on major organs. Thus, we picture that the developed SLNs may benefit in delivering IRI to the tumour cells, therefore decreasing the dose and dose-associated toxicities.