| Cyclodextrins(CDs)are family of cyclic oligosaccharide molecules, which areconstructed fromα(1â†'4)-linked glucose units and known for their capability toencapsulate lipohilic molecules. CDs are divided into α-, β-and γ-cyclodextrins dependenton their assembly of six, seven or eight glucose molecules. Characteristically, they have acylindrical form with a lipophilic cavity and a hydrophilic exterior part. The bindingconstant is an important physical and chemical parameter which is related to the bindingability of CDs. We could make a quantitative description of the bonding equilibrium bydeterminating the value of binding constant, which reflects the bonding force of CDs anddrug combined into an inclusion complex.<ugammadex, a synthetic γ-cyclodextrin, which has the ability of reversing theneuromuscular blockade induced by the steroidal neuromuscular blocking agentsrocuronium or vecuronium. Sugammadex has little bioactivity, does not bind to plasmaproteinsand appears to be safe and well tolerated. Clinical researches have demonstratedthat Sugammadex can reverse any level of steroidal neuromuscular blockaded byrocuronium or vecuronium without undesirable adverse effects.As a revolutionaryneuromuscular blocker, it changed the concept of neuromuscular blockade pharmacologywhen introduced into clinic.Although Sugammadex is an effective muscle relaxant antagonists, high priceslimited its wide application. Amo0498-16, the target of our study, which was developedbased on <ugammadex.9hey are all modified γ-cyclodextrin and have similarchemical structure. This paper aims to study the inclusion ability of Aom0498-16andSugammadex with drugs and investigate whether Amo0498-16has equivalent inclusionability with Sugammadex. So this study could provided a solid theoretical support forAom0498-16entering clinical trials as a innovative drug which has similaraction mechanism with Sugammadex. Therefore, we conducted a comparative study ofAom0498-16, Sugammadex, Aom0498-16synthetic material γ-CD with a group of strongaffinity drugs first. In order to looking for drugs which may also have strong interactionswith Sugammadex or Aom0498-16,we made comparative studies of Sugammadex andAom0498-16with five categories of drugs, including cardiovascular system drugs,central and peripheral nervous system drugs, immune system drugs, drugs act on theblood, respiratory, digestive, chemotherapy drugs and endocrine drugs. During the screening process, in order to save analysis time and cyclodextrin consumption, we fixedconcentration of cyclodextrin additives in the buffer, then divided every category of drugsinto several groups of mixtures and injected simultaneously. So we could sort themigration time ratio of drugs and select drug which has the largest migration time ratio ineach group to determine the binding constants.The content of thesis was divided into sevenchapters,In the first part, we developed the method of determinating the binding constantsbetween CDs and drugs. Capillary electrophoresis is one of the most interesting methods instudying the interaction mechanism of CDs and drugs. It has the advantages of efficient,fast and low consumption of sample.=hat’s more, drugs could be measured at pcondition close to body fluids. Through changing the cyclodextrin concentration in runningbuffer, we got the relationship between the effective electrophoretic mobility andcyclodextrin concentrations and then could calculated the binding constants with thedouble-reciprocal method. The effect of separation voltage, concentrations and pH ofborate-phosphate buffer, injection modes, time and voltage were investigated to achievehigher sensitivity and better running time. The separation was carried out at25℃in a31.2cm×75μm fused-silica capillary with an applied voltage of10kV for calculating thebinding constants or in a61.0cm×75μm fused-silica capillary with an applied voltage of28kV for ordering the migration time ratios. The background electrolyte was composed of8.25mM borate-35mM phosphate (pH7.0). The sample was introduced by electrokinetic(7.5kV×30s) or pressure injection (0.5psi×10s) modes. The detection wavelength were setbetween190nm and300nm.The second part was the comparative study of the interaction between Aom0498-16,Sugammadex, Aom0498-16synthetic material γ-CD and strong affinity drugs. We selectedrocuronium, vecuronium, toremifene and fusidic acid according to references whichdemonstrated that they have strong interaction with Sugammadex. With the increase of theconcentrations of Aom0498-16and Sugammadex, peak height of drugs decreasedgradually until disappeared. The inclusion ability of γ-CD was significantly smaller thanthese two cyclodextrins. The results showed that, the interaction between Aom0498-16androcuronium or vecuronium was equivalent to Sugammadex and slightly better for fusidicacid and toremifene. It is fully demonstrated that Aom0498-16has potent physicalinclusion ability and could be introduced into clinical trials as a innovative drug which hassimilar action mechanism with Sugammadex. The third part was study of the interaction between Aom0498-16, Sugammadex andcentral, peripheral nervous system drugs. We selected15kinds of central and peripheralnervous system drugs and divided into four groups. The cyclodextrin concentration was setat1.0mg/mL. The capillary column length of61.0cm was selected to preliminary sortingthe migration time ratio of drugs. When Amo0498-16was added, the drugs which had thebiggest migration time ratio in these groups were mirtazapine (1.668), clozapine (1.642),fluoxetine (1.836) and etomidate (1.201), respectively. When Sugammadex was added, thedrugs which had the biggest migration time ratio in these groups were mirtazapine (2.088),atropine (2.705), fluoxetine(2.729) and etomidate (1.395), respectively. Then measured thebinding constants of Amo0498-16or Sugammadex with mirtazapine, clozapine,atropine,fluoxetine and etomidate and they were3.13E+03,3.32E+03,2.33E+03,1.98E+03,5.65E+02and1.04E+03,4.39E+03,4.72E+03,1.20E+03,4.53E+02, respectively. Theresults showed that, the affinity between drugs and Amo0498-16were equal or slightlysmaller than Sugammadex.The fourth part was study of the interaction between Aom0498-16, Sugammadex andcardiovascular system drugs. In this paper, we selected12kinds of cardiovascular systemdrugs and divided into three groups. The cyclodextrin concentration was set at1.0mg/mL.The capillary column length of61.0cm was selected to preliminary sorting the migrationtime ratio of drugs. When Amo0498-16was added, the drugs which had the biggestmigration time ratio in three groups were propranolol (1.315), esmolol (1.447) andverapamil (1.304), respectively. When Sugammadex was added, the drugs which had thebiggest migration time ratio in three groups were propranolol (2.657), amlodipine (3.149)and verapamil (3.163), respectively. Then we measured the binding constants ofAmo0498-16or Sugammadex with propranolol, esmolol, verapamil, amlodipine and theywere5.26E+02,4.85E+02,6.38E+02,3.85E+02and9.11E+02,1.51E+03,2.81E+03,2.52E+03, respectively. The results showed that, the affinity between drugs andAmo0498-16were smaller than Sugammadex.The fifth part was study of the interaction between Aom0498-16, Sugammadex anddrugs related to immune System and drugs act on the blood, respiratory, digestive. In thispaper, we selected9kinds of drugs and divided into two groups. The cyclodextrinconcentrations was set at1.0mg/mL. The capillary column length of61.0cm was selectedto preliminary sorting the migration time ratio of drugs. When Amo0498-16was added,the drugs which had the biggest migration time ratio in two groups were desloratadine (2.500) and loperamide (1.557), respectively. When Sugammadex was added, the drugswhich had the biggest migration time ratio in two groups were desloratadine (3.086) andloperamide (1.924), respectively. Then we measured the binding constants of Amo0498-16or Sugammadex with desloratadine and loperamide and they were2.73E+04,1.10E+03and1.37E+04,3.97E+03, respectively. The results showed that, the affinity between drugsand Amo0498-16were similar to Sugammadex.The sixth part was study of the interaction between Aom0498-16, Sugammadex andchemotherapy drugs. In this paper, we selected10kinds of drugs and divided into twogroups. The cyclodextrin concentrations was set at1.0mg/mL. The capillary column lengthof61.0cm was selected to preliminary sorting the migration time ratio of drugs. WhenAmo0498-16was added, the drugs which had the biggest migration time ratio in twogroups were gatifloxacin (1.333) and econazole (3.363). When Sugammadex was added,the drugs which had the biggest migration time ratio in two groups were gatifloxacin(2.382) and econazole (3.192). Then we measured the binding constants of Amo0498-16orSugammadex with gatifloxacin and econazole and they were6.34E+02,5.20E+04and1.34E+03,5.75E+04, respectively. The results showed that, the affinity between drugs andAmo0498-16were slightly smaller than Sugammadex.The seventh part was study of the interaction between Aom0498-16, Sugammadexand endocrine drugs group. In this paper, we have selected12kinds of drugs. All the drugshave similar chemical structures with rocuronium and high affinity with Amo0498-16andSugammadex. So we used the shorter capillary column (31.2cm) to measure the bindingconstants of Amo0498-16or Sugammadex individually. The results showed that, theaffinity of most of drugs with Amo0498-16were similar to Sugammadex.After compared the two methods of sorting migration time ratio and binding constants,we found that all the drugs had nearly the same sequence of affinity with Sugammadex andAmo0498-16, which means most of the drugs had similar affinity to Sugammadex andAmo0498-16.The values of migration time ratio were relevant to binding constants and theexperiment results were reliable and trustworthy. |
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