Piracetam Drug Pharmacokinetics And Mass Spectrometry Regularity

This paper focused on the Pharmacokinetics properties of piracetam, aniracetam and levetiracetam in Chinese healthy volunteers, including the dissociation pathways of five 2-pyrrolidone derivatives by use of electrospray ion trap mass spectrometry, and then to supply reference to the clinical application or development of this kind of drugs.Randomization and oral administration were applied in the PK research. The concentrations of target drugs in serum and urine were determined by HPLC. The main pharmacokinetic parameters were calculated with DAS2.0 practical PK program. ESI-MSⁿ method and positive mode were used in the study of dissociation pathways.The in vivo process of piracetam accorded with the two-compartment model, yet that of levetiracetam and ABA, the metabolite of aniracetam, accorded with the one-compartment model. The t_1/2 of piracetam and levetiracetam were about 6h, yet that of ABA was about 0.6h. The T_max of piracetam and ABA were about 0.7h, yet that of levetiracetam was about 1.2-1.8h. The C_max and AUC of three concerned drugs were all high. The study indicated that this type of drugs present the feature of rapid and full absorption, short T_peak and high blood drug level. The statistical analysis proved that levetiracetam exhibited linear kinetics, no accumulation after multiple dosing, obvious steady state and was mainly excreted unchanged in the urine.The assay methods we developed for pharmaceutical analysis in vivo were simple, rapid, accurate and sensitive. They agreed with the requirements of biological specimen analysis and were suitable for the study of bioavailability and PK. By means of multiple-stage MS scan, we could know that the tested compounds had the similar clearage modes except for aniracetam. It showed that the structural information could be quickly obtained via ESI-MSⁿ method and these characteristics were applicable to the structural elucidation and quantitative analysis of 2-pyrrolidone derivatives.