ZHANG Lixing, DU Liping, FENG Zhong, HAO Guizhou
Gefitinib (1) is a novel medicament for a targeted tumor therapy. It is used in the treatment for latestage non-small cell lung cancer. The marketed formulation of 1 is tablets with low absorption and oral bioavailability. However, the adverse reactions of 1 are exacerbated with the increasing of dosage. To improve the poor oral bioavailability of 1, its inclusion complexes had been environmental-friendly synthesized by mechanochemical technology with GMS 10-8 roll mill in this study. Arabinogalactan (AG) and hydroxypropyl-β-cyclodextrin (HP-β-CD) were separately used as inclusion carriers for 1. The synthesized complexes were characterized by nuclear magnetic resonance (NMR) relaxation technique (T2), scanning electron microscopy (SEM), differential scanning calorimetry(DSC), powder X-ray diffraction (P-XRD). Results of in vitro tests showed that the solubility of 1 was increased from 0.77 g/L to 2.16 g/L, and the dissolution at 120 min was increased from 60% to 92% of its mechanochemical treated complexes with HP-β-CD. Similarily, the solubility of 1 in its complex with AG was increased to 1.32 g/L, and the dissolution at 120 min was increased to 75%. Pharmacokinetic behaviors of these inclusion complexes were investigated with male SD rats as the animal models. The rats were divided into 4 groups: injection group with 1 (10 mg/kg), intragastric administration groups with 1, 1/AG inclusion complexes or 1/HP-β-CD inclusion complexes (50 mg/kg). Results showed that the absolute bioavailability of 1 in rats with intragastric administration were 56.94%, 81.63% and 78.48% for 1, 1/AG inclusion complexes and 1/HP-β-CD inclusion complexes, respectively. In conclusion, the two synthesized complexes of 1 were in formation of the inclusion, with increased solubility, dissolution in vitro and absorption in vivo. It indicated that the mechanochemical technology was a promising approach to develop 1 solid oral dosage forms with decreased dosage and improved oral bioavailability.