Determination Of Anti Leukemia Drug Thermodynamic Calorimetry Parameters

Drugs’ Thermodynamic and kinetic parameters are one of the important data on study the human metabolic mechanism.They are also used to measure efficacy of drugs.Although scientific research and technical personnel according clinical animal experiment and highperformance liquid chromatography to track the change of haemoconcentration,the differ between measurements with the half-life of the drugs because of the change of environment effects on people and individual difference,it make the difference between the measured value and the half-life of the drug.So we hope that we can find safer and more simple and reliable method than traditional to measure thermodynamics and kinetics.In this paper,we have two kinds of anti leukemia drugs:Cytarabine and Cyclophosphamide.We are researching the Dissolution behavior of Cytarabine and Cyclophosphamide in normal saline,citric acid solution and DMSO get the differential dissolution heat,build the equation between the solute with heat,we also build the kinetic equation which are Cytarabine and Cyclophosphamide dissolute in normal saline,citric acid solution and DMSO and calculate the dissolution half-life 、 molar dissolution enthalpy 、molar dissolution entropy、molar Gibbs free energy and activation energy.The results were as follows:(1)The both dissolution enthalpy was less than 0,illustrate that the dissolution of Cytarabine and Cyclophosphamide both are endothermic process;The change of Cyclophosphamide’s molar dissolution enthalpy is small in different solvents,so we can express the Cyclophosphamide’s molar dissolution enthalpy with its average;Among them,Cyclophosphamide’s molar dissolution enthalpy is-22.42 k J·mol-1in normal saline,is-5.408 k J·mol-1 in citric acid solution,the both values are small,illustrate that the dissolution of hydrogen bond energy can be small and easy fracture and absorbed by human body.(2)Cytarabine and Cyclophosphamide’s molar dissolution entropy are both less than0,illustrate that system more stable after drug dissolution.(3)The dissolution half-life is same to the drug half-life achieve from rate of heat change of the process of experiment and kinetics equipment.So we can illustrate that our method is reliable on measure the half-life.They can provide the data for dosage of clinical medication usage.