Determination Of Memantine Concentration In Human Plasma Utilizing The Liquid Chroma Tography-tandem Mass Spectrometry Method And Research Of Bioequivalence

BACKGROUD With the aging of the population has become increasingly obvious, China will become the first in the total number and the growth rate of Alzheimer’s patients in the world. The prevention and cure of Alzheimer’s disease will be as a serious public health problem. Memantine is an effective drug approved for the treatment of moderate to severe Alzheimer’s disease. Since the expiration of the patent in abroad, many domestic enterprises have accelerated to develop memantine hydrochloride generic drugs. According to the Chinese Food and Drug Administration (CFDA), regulations bioequivalence studies must be carried out. Memantine domestic development will greatly reduce the cost of treatment costs, and bring substantial benefits to society and patients.OBJECTTIVE One aim of this study was to establish a liquid chromatography-tandem mass spectrometry method (LC-MS/MS) for the determination of memantine concentration in human plasma. The other aim of this study was to assess pharmacokinetic parameters and relative bioavailability of single dose related memantine and reference preparation, and to evaluate the bioequivalence of two preparations.METHODS Samples were extracted by ethyl acetate:methylene chloride, and isolated with methanol:water=95:5(V:V, including0.005mol·L-1ammonium formate and0.1%formic acid) as mobile phase using Agilent Eclipse plus C18(4.6mm×150mm,3.5microns) column. Quantification was performed using multiple reaction monitoring (MRM) of the transitions m/z180-163for memantine using electrospray ionization source and positive ion detection using multiple reaction monitoring (MRM) manner.Using single center, open, group, two groups of healthy subjects were randomly assigned to take the test preparation and reference preparation10mg for bioequivalence study. Determine memantine concentration in human plasma by LC-MS/MS, assess relative pharmacokinetic parameters(including plasma concentration time curve,AUC, Cmax and Tmax), and to evaluate the bioequivalence of two preparations. RESULTS The method showed that a good linearity in a concentration range of0.2-30μg·L-1for memantine with the minimum quantitative limit of0.2μg·L-1. The accuracy and precision was good and the absolute recovery was above70%. Medium effect does not affect the determination of the quality of drugs. Results indicated that the memantine test formulation of AUC(0.t)90%confidence interval is the reference formulation corresponding argument98.6%～101.8%, the test formulation of AUC(0-∞)90%confidence interval is the reference formulation corresponding argument98.6%～102.1%, and the test formulation of Cmax90%confidence interval is the reference formulation corresponding argument96.3%～103.9%. Tmax of the test formulation and a reference formulation indicate no significant differences with Wilcoxon test method (P>0.05).CONCLUSION:This validated method showed that it was a selective, rapid and sensitive method for investigating plasma drug concentrations in human plasma. Based on analysis and comparing pharmacokinetic parameters of a single oral dose of the test and reference preparations in40healthy volunteers, the two preparations are showed bioequivalent. There are totally5figures,23tables and51references.