Preliminary Study On The Pharmaceutics Of Targeting EGFR Quinazoline Compounds

Activation of the epidermal growth factor receptor(EGFR)has been linked to tumor proliferation,invasion,metastasis and angiogenesis in epithelial tumors,which is a vital target for oncotherapy.A novel series EGFR inhibitors have been introduced,since the successful listing of the gefitinib.Three different types of quinazoline compounds targeting EGFR were designed and synthesized successfully in the early stage of our research group.Based on the results of the biological assay,the four quinazoline compounds(I4,I6,I7,I8)have excellent activities against EGFR and anti-proliferation of tumor cells.The thesis based on the results of the previous studies of our research group,the preliminary studies on the drug properties of four quinazoline compounds that expects to provide the foundation for the relevant in-depth research of the above compounds.The main contents are summarized as follows:Based on the synthesis route of the previous four quinazoline compounds I4,I6,I7 and I8,starting from the 5-bromo-2-aminobenzoic acid as the starting material,the amplification synthesis of the target compounds were performed through four-step chemical reaction.Each reaction condition was well controlled.Four target compounds and intermediates were obtained and characterized by1H-NMR,13C-NMR and ESI-MS.Compounds I4,I6,I7,and I8 are all basic compounds.We added five different inorganic and organic acids such as hydrochloric acid,hydrobromic acid,phosphoric acid,citric acid and maleic acid to the methanol solution of the compound to prepare 16 corresponding salt-type compounds.The solubility of the free base compounds and its related salts were determined by HPLC in artificial gastric juice,artificial intestinal fluid and physiological saline.The results showed that the solubility of citrate of compound 14,hydrochloride and hydrobromide of compound 16,and maleate of compound 18 increased significantly,while the solubility of five salts of compound 17 did not increase significantly compared with the free alkali.In the artificial gastric fluid,the solubility of citrate of compound 14 was 42.65 mg/mL,which was 13 times higher than that of free base(3.26 mg/mL).The solubility hydrochloride of compound 16 was 195.20 mg/mL and hydrobromic of compound 16 was 134.95 mg/mL,and the solubility increased by 12-fold and 8-fold respectively compared with its free base(16.77 mg/mL).The solubility of maleate of compound 18 was 16.50 mg/mL,compared with its free base(8.80 mg/mL),the solubility increased by nearly double.The methods of the content determination for the above four quinazolines tyrosine kinase inhibitors were established via adopting external standard method of Ultra high-pressure liquid(UPLC)and the absolute quantitative model of Nuclear magnetic resonance(qH-NMR),and validation test of the related content determination method were also performed.The consequence of the measurement of the UPLC were 98.79%,97.15%,98.50%,92.14%,respectively and the results of qH-NMR were 96.55%,97.18%,98.42%,and 91.41%,respectively.The two methods for determining the content of compounds are consistent.A preliminary study was conducted on the pharmacokinetics of compound 16 and its hydrochloride in Kunming mice.The UPLC liquid phase method was used to determine the mouse plasma concentrations of the free base and the hydrochloride.The results showed that the pharmacokinetic parameters of compound 16 and its hydrochloride administered to mice by gavage:tmax = 6.0h,0.5 h,respectively;t1/2=1.769±0.043,2.019±0.340 h,respectively;Cmax = 1.193±0.464,3.297±0.112 mg.L-1,respectively(P<0.005).Pharmacokinetic parameters of hydrochloride(25 mg/kg)administered to the tail of mice:tmax = 0.25 h;t1/2 0.623±0.250 h;Cmax=5.475±0.524 mg.L-1,(P<0.005).Absolute bioavailability of Compound 16 and its hydrochloride mice was 34.32%and 59.33%,respectively.The absolute bioavailability of hydrochloride had increaed 73%while compared to its free base.Conclusion:The preliminary characterization of the above quinazoline compounds were performed in this paper.Among the enlarger synthesis scale,the purity both compound 14 and compound 17 were more than 98%.The determination of the solubility showed that the solubility has a various degree of increase after the salt formation,such as the solubility of I6-hydrochloride increased 12-fold while its biovailability increased 73%comparing to its free base.The thesis has been provided experimental basis for the further studies of the above quinazoline compounds as the candidate drugs.