Ribociclib Hybrid Lipid–Polymer Nanoparticle Preparation and Characterization for Cancer Treatment

Ribociclib is a newly approved orally administered drug for breast cancer. This study aimed to prepare, characterize, and evaluate hybrid lipid–polymer nanoparticles (PLNs) of ribociclib to enhance its in vitro dissolution rate, pharmacokinetics, and anticancer efficacy. Ribociclib-loaded PLNs were prepared by solvent evaporation using the Box–Behnken design to optimize formulation variables. Particle size, entrapment efficiency, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), in vitro release cytotoxicity, molecular modeling, and pharmacokinetic studies were examined. The ribociclib-loaded PLN (formula 1, F1) was optimized in terms of particle size (266.9 ± 4.61 nm) and encapsulation efficiency (59.1 ± 2.57 mg/mL). DSC and thermogravimetric characterization showed the absence of a crystalline structure in the prepared PLNs, confirmed by FTIR, and showed no interactions between the components and the drug. AFM showed well-dispersed heterogeneously shaped nanoparticles. The in vitro release profile exhibited significant results for the optimized formula, reaching 100% at 600 and 90 min at pH 6.8 and 1.2, respectively. The low IC50 obtained by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay suggests that optimized PLN might serve as an effective delivery vehicle for cancer treatment, especially breast and lung cancer. Molecular modeling revealed several hydrogen bonds. A pharmacokinetic study in rats showed that the ribociclib formula had a 6.5-fold increase in maximum concentration (Cmax) and a 5.6-fold increase in area under the curve (AUC). Regarding the everted intestinal sac absorption, formula 1 increased ribociclib penetration relative to the physical combination and pure medication. In conclusion, optimized PLNs with enhanced physicochemical and cytotoxic properties and improved pharmacokinetic parameters were successfully prepared.