| Cancer had become a major disease threatening human health with lung cancer ranked first,non-small cell lung cancer(NSCLC)accounted for about 80-85%.Molecular targeted medicine based on tyrosine kinase inhibitors,which was orally administered,opened the door for the treatment of NSCLC.Drug reposition,a study of new indications or targets for marketed drugs,was one of the ways for development of new drugs,with lots of advantages,such as short development cycle,low cost,improved efficacy.Nintedanib ethanesulfonate(NDNB),a multiple receptor tyrosine kinases inhibitor,was clinically used for the treatment of pulmonary fibrosis and NSCLC with low oral bioavailability(4-5%).Its solubility decreased rapidly as p H increased,and it was a substrate of P-glycoprotein(P-gp)and CYP3A4.Itraconazole(ITZ),a potent P-gp and CYP3A4 inhibitor,showed good effect on NSCLC.Thus,we intended to prepare co-inclusion complex of NDNB and ITZ,and evaluate the characteristic on pharmaceutics,absorption,pharmacodynamics and safety of complex.NDNB,ITZ and NDNB/ITZ supramolecular inclusion complex with HP-?-CD as host were prepared by the dissolution-p H adjustment method,respectively.The results showed that NDNB/HP-?-CD complex with inclusion rate of 96% was prepared by NDNB: HP-?-CD of 1:20(molar ratio),stirring at 25 ? for 0.5 h,and adjusting p H to 6.8.Phase solubility studies suggested AL type for NDNB/HP-?-CD inclusion complex.XRD showed no characteristic diffraction peaks for NDNB or ITZ in single or co-inclusion formulations,suggesting molecular or amorphous form both for NDNB or ITZ.FT-IR further showed hydrogen bond interaction among NDNB and ITZ with HP-?-CD.Dilution stability of complex was the prerequisite to promote absorption and bioavailability.The effects of drug loading ratio,ionic species and concentration on recrystallization of single and co-inclusion complex of NDNB were studied using physical and physiological dilution method.The results of the physical dilution method showed that the unstability of NDNB inclusion complex in several solutions followed the order: HCO3-> H2PO4-> Cl-.The higher ionic concentration,and the lower molar ratio of HP-?-CD,the easier to recrystallize for NDNB.However,for ITZ inclusion cpmplex,only concentration of HP-?-CD would impact on stability,regardless of ionic species and concentration.Besides,co-inclusion complex exhibited similar characteristics as single complex.The simulated physiological dilution result showed excellecnt stability of NDNB complex(molar ratio 1:20)along the physiological p H environment and transition time.However,ITZ precipitated in the simulated jejunum segment due to unsufficient concentration of HP-?-CD,indicating earlier release of ITZ than NDNB in co-inclusion complex.In situ single pass perfusion was commonly used to study the intestinal permeability and pathways to transport for drug delivery systems.Since unstability of ITZ in co-inclusion complex,we explored the permeability difference of NDNB by sequential perfusion with ITZ and NDNB inclusion complex or NDNB complex alone in order to explore the role of ITZ on absorption of NDNB.The results showed that the permeability constant(Ka)and apparent permeability(Papp)of NDNB inclusion complex were significantly higher than those of NDNB aqueous solution(p <0.05).Sequential perfusion of ITZ and NDNB inclusion complex increased the Ka and Papp of NDNB inclusion complex in each intestinal segment with statistical difference,indicting significant improvement on permeability of NDNB by combination with ITZ.After perfusion of NDNB inclusion complex at 10-30 ?g/m L,there was no statistical difference in permeability.Permeability of NDNB inclusion complex at 60 ?g/m L was significantly improved yet,demonstrated passive diffusion absorption which was closely related to the intestinal P-gp.For the purpose of study oral bioavailability of NDNB in co-inclusion complex,the pharmacokinetics was performed.The results showed low plasma concentration of NDNB complex solution,which was close to the limit of quantitation.Therefore,complex gel was prepared to prolong the residence time in gastrointestinal tract(GI)aiming at increasing its absorption.Compared with NDNB commercial soft capsules,NDNB inclusion complex gel improved the absolute bioavailability of NDNB from 4.7% to 12.2%.In sequential oral administration of ITZ and NDNB inclusion complex gel,the bioavailability of NDNB increased to 28-32%,while the bioavailability reached 65% in co-inclusion complex gel.It was obvious that the co-inclusion complex gel increased the solubility both of NDNB and ITZ,prolonged the residence time in the intestine,and inhibited the efflux of P-gp on NDNB,significantly improved the oral bioavailability of NDNB.In order to further study the in vivo safety and anti-cancer efficancy of co-inclusion complex gel,Lewis lung cancer-bearing mice was constructed by subcutaneous injection.ITZ and NDNB inclusion complex gel,sequential administration of ITZ inclusion complex gel and NDNB inclusion complex gel,and co-inclusion complex gel was administered orally once a day.After 10 days' administration,the tumor inhibition rates of four treatment regimens on Lewis lung cancer-bearing mice were 7.69%,21.00%,24.15%,and 36.98%,respectively.Among them,the tumor was significantly inhibited in co-inclusion complex gel group(p <0.01),while tumors in the NDNB/HP-?-CD group and the sequential administration group was significantly(p <0.05)inhibited.There were no significant anti-tumor effects in ITZ inclusion complex gel and HP-?-CD.According to the calculation of the King's formula,sequential administration(Q=0.89)exhibited the additive anti-cancer effects,while co-inclusion complex gel(Q=1.36)showed synergistic anti-cancer effect.Safety experiments showed that the number of renal corpuscles in the kidneys of the ITZ-encapsulated gel group,sequential administration group,and co-inclusion gel group decreased,cells around alveolar tissue increased,collagen deposition increased,and the cell morphology of the rest of organs,stomach and intestine were normal,and it had good safety. |
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