Synthesis and optimization of gemcitabine-loaded nanoparticles by using Box-Behnken design for treating prostate cancer: In vitro characterization and in vivo pharmacokinetic study

Gemcitabine (GC)-loaded chitosan nanoparticles were synthesized by ionic gelation method, and optimization was accomplished by Box-Behnken design based on particle size (PS), polydispersity index (PDI), zeta potential (ZP), and percent entrapment efficiency (% EE). The optimized formulation (OF) exhibited PS, PDI, ZP, and % EE to be 206.7 nm, 0.285, +27 mV, and 77.61%, respectively. Fourier transform infrared spectroscopy, X-ray diffraction analysis, and differential scanning calorimetry analyses confirmed GC's stability in nanoparticles. The OF showed an initial rapid release of 61%, followed by a slower release, reaching 95.81% over 96 h. OF was studied on a PC-3 cell line to evaluate its effectiveness in treating prostate cancer, where it exhibited higher cytotoxicity (IC₅₀∼3.06 ± 0.32 μg/ml) compared to pure GC (IC₅₀∼4.11 ± 0.81 μg/ml). After oral administration in albino rabbits, the peak plasma concentrations (C _max) for GC solution and OF were 1,290 and 3,070 ng/ml, respectively. The time to reach maximum plasma concentration (t _max) was 1 h for GC solution and 6 h for OF. The half-life (t _1/2) was 5.6 h for GC solution and 16.9 h for OF, indicating a prolonged half-life for OF. OF demonstrated an effective release pattern of GC, improved stability, enhanced pharmacokinetic profile, and higher toxicity compared to GC.