The Research Of Aggregate Formed By Bile Salts Mixed System

Interactions in mixed sodium deoxycholate(NaDC)/sodium oleate(NaOL) and NaDC/polyoxyethlene-10-oleyl ether(Brij97) systems in0.9%NaCl were studied by wilhelmy plate method, which could provide the scientific basis for their phase behavior. Then phase behavior and rheological properties of aggregates with different mixed proportions of surfactants mentioned above were studied. In this paper, influence of different mixed proportions of surfactants on phase behavior and rheological properties was researched, using polarization microscope and TA-2000ex rheometer, and changes in oil with fixed surfactant proportion was further studied. Control-release of curcumin solubilized in lyotropic liquid crystal formed in NaDC/Brij97system was studied. It is found that lyotropic liquid crystal formed in the system above shows sustained release effect. All the work above could have some certain referential value for basic research and application in drug carrier. This paper includes four chapters as following: 1. IntroductionAfter researching the related references about the investigation of sodium deoxycholate in the domestic and overseas, the article summarizes the research of bile salts concentrated on phase behavior and the formation and characterization of its lyotropic liquid crystals. Sodium deoxycholate and water systerm can form hexagonal liquid crystal but the region is relatively narrow, so the research is focused on the mixed systems constituted by sodium deoxycholate and other surfactants. The research reveals that the lyotropic liquid crystals region of mixed systerm turns lager and the phase behavior becomes richer. Therefore this paper takes sodium deoxycholate as research object to study the interaction and phase behavior of mixed systems composed of sodium deoxycholate and anionic surfactant or nonionic surfactant, then sustained release of curcumin encapsulated in lyotropic liquid crystals formed by NaDC/Brij97system is studied in Chapter four.2. The phase behavior and rheological properties of NaDC/NaOL systemFirst the surface properties and molecular interactions of NaDC/NaOL system in0.9%NaCl at37℃were studied, then the proper mixed ratios of surfactants were confirmed to investigate the phase diagram of NaDC/NaOL system at37℃. The changes of phase behavior and rheological properties resulted from the transformation of mixed ratios of NaDC/NaOL from1:1to1:2and1:3were researched. The results found that the lamellar phase was turned to biocontinuous cubic phase with the increasing NaDC. When the mixed ratio of NaDC/NaOL was fixed to1:2and the oil was changed by oleic acid, the lyotropic liquid crystals region of mixed systerm turns narrower. Furthermore, at low oleic acid content the viscoelasticity of oleic acid system is similar to that of IPM system; while the viscoelasticity reduced at the high oleic acid content as the oleic acid molecules insert into the surfactant molecular layer.3. The phase behavior and rheological properties of NaDC/Brij97systemThe surface properties and molecular interactions of NaDC/Brij97mixed system in0.9%NaCl at37℃were summarized, and then we constructed the phase diagram of NaDC/Brij97(1:3)/IPM/H2O system in which hexagonal and cubic phase liquid crystal were found. The rheological properties were studied using the TA-2000ex rheometer, and the steady shear rheology results indicate that th e la m el l a r li q u id c r ys ta ls sh ow sh e a r th i nn i n g fl u i d ph a se be ha vi o r, a nd dy n a m ic e xp e ri m e nt a l re su l t s c an w e ll c om pl y w it h M ax w e ll m od e l. C o m pa re d w it h pr e vi o us re se a rc h Bri j97/I PM/H2O sy s te m, add i n g o f N aD C in c re a se th e vi s c oe la st i c pr o p ert y of sy s t e m. Ph a se tr a ns i t i o n oc c u rs a t58oC aft e r th ec on t i n u ou s te m pe ra tu re sc a nn i n g.4. T he c ur c um i n re le as e be ha vi o r in th e ag g r ega t e of N aD C/B ri j97sy s t e mTh e vi tr o re le a se be ha vi o r of c ur c um in in th e l iq ui d c ry st a ls a s dr u g ca rr i e rw a s in v est i g a te d. T he re s ul t s s ug ge st th e dr u g in th e li q u id c ry s t a l s m a in l y re le ase d i n th e fo r m of di f f us i o n a n d re le a se pr o c ess was in li n e w it h th e fi r s t or d e r ki n e ti c s.W he n th e qu a li t y of c u rc um in w as sa m e, th e m or e oi l in th e dr u g c ar r i e r, th e gr e a te r th e dr u g re le a se ra te. A n d th e re le as e ra te of c ur c um in in li q ui d c ry s t a l sc a rr i e r sa m pl e wa s lo w er th a n th a t in e th a no l so l u ti on.