Studies On UHPLC-MS/Ms Monitoring Common Anticancer Drugs And Research About The Interaction Between Cyclophosphamide And Ketoconazole

Cancer is one of the leading causes of death in clinic. The common treatments againstcancer include chemotherapy, surgery and radiation therapy, chemotherapy is the mostwidely used one among them. Traditionally, the common anticancer drug can be dividedinto several different groups, such as alkylating agent, anti-metabolite, antibiotics, andhormone from plant. Recently, as the pharmaceutical engineering technique developing,the target selectivity of anticancer drug has increased, while the related adverse reactionand the therapy effect between different individual patients are inevitable. According to thepharmacokinetic and pharmacology study, we acquire that anticancer drugs play its roledue to their specific metabolite, no matter it’s active or toxic. So, we’d like to take insightinto the quantification of the parent drug and their metabolites and then get knowledgeabout the timely concentration, which can help us acquire the detailed metabolism ofanticancer drug in vivo.TDM, namely therapeutic drug monitoring, is the study which is operated viatechniques like gas chromatography, liquid chromatography and mass spectrometer, theresearchers get the access to directly to quantify the parent drug and metabolite in plasmaand then be able to evaluate the efficacy and ensure the treatment therapy. UHPLC-MS/MS(ultra high performance liquid chromatography tandem mass spectrometry) is a newlydeveloping technique, it has advantages like short runtime, high resolution, and smallrequirement for sample amount against the other analytical techniques. In our study, we’dlike to monitor several parent anticancer drug and their specific metabolites by usingUHPLC-MS/MS, the analytes include gemcitabine and diflurouridine, vinorelbine anddeacetyl vinorelbine, etoposide and desmethyl etoposide, cyclophosphamide anddechloroethylcyclophosphamide. The waters T3C18column (2.1×100mm,1.7μm) wastaken in the study for the previous6analytes, the elution consists of water (0.1%formicacid contained, phase A) and acetonitrile (0.1%formic acid contained, phase B). Thevalidation of the method includes specificity, linearity, extraction recovery, matrix effectand stability test. The classical protein precipitation was taken the sample treatment,3-foldvolume acetonitrile (0.1%formic acid contained) was used as precipitation reagent, and thelimited runtime and the simple pretreatment method make sure that the developed methodcan meet the requirement of high-throughput analysis in clinic.Cyclophosphamide (CP) is a commonly used cytotoxic agent, its typical neuro adverse effect was caused by the dechloroethylation pathway. As we know, thismetabolism pathway is mediated by CYP3A4, it can lead to the products likedechloroethylcyclophosphamide (DECP) and chloroacetaldehyde and thechloroacetaldehyde is regarded as the biomarker of the neuro adverse effect forcyclophosphamide in clinic. DDI (drug-drug interaction) usually happens when onecompound affect the activity of some CYP enzyme, then this CYP enzyme mediated drugcan’t play its function as usual. Ketoconazole (KTZ) is a potentially CYP3A4inhibitor, inthe well known DDI model between ketoconazole and midazolam, it works significantly toreduce the production of2-hydroxy midazolam. Similarly, we hope the DDI between KTZand CP can decreased the extent of dechloroethylation pathway related to CP, thus reduceits neuro adverse effect. In the incubation environment, by using the human microsome, wehave validated the dechloroethylation pathway of CP, when co-administrated with KTZ,the amount of dechloroethylcyclophosphamide decreased, it proves that KTZ really workswhen co-administrated with CP.In the following study, we have validated the DDI between CP and KTZ in rats. Therelated plasma concentration was acquired by using UHPLC-MS/MS, the results indicatedthat when co-administrated with KTZ in mouse, the dechloroethylation ofcyclophosphamide was significantly reduced. DECP levels (calculated as the mean AUC0-∞value) in plasma decreased with the increasing dose of CYP3A4inhibitor KTZ, showing a51.19%decrease in AUC0-∞of control group (dosage of CP,10mg/kg, i.v.), with10mg/kgKTZ in combination (dosage of CP,10mg/kg, i.v. and KTZ10mg/kg, p.o.). The resultsindicate that we can possibly develop therapy interventions against the neuro effect of CPby the co-administration of both CP and the potent CYP3A4inhibitor. It’s no doubt that theenzymes involved with biotransformation of drugs are complex and our research onlyfocused on the CYP3A4enzyme. However, the study based on both the animal model andmirosome model can provide us some guideline to promote rational drug use in clinic.