Microdialysis Combine with Hollow Semipermeable Membrane Microextraction
|Keywords||microdialysis hollow semipermeable membrane microextraction pharmacokinetics plasma protein binding ratio|
Microdialysis sampling, as an in vivo technique, makes possible the investigation of biochemical events in the extracellular fluid of virtually any tissue, organ or biological fluid. It has become to be an important tool in the research of pharmacokinetics, neuropharmacology and nurochemistry. As using the aqueous solution as perfusate, there is a low recovery in the dialysis of nonpolar substances, so it is not suit for sampling and detecting nonpolar substances.As a sample pretreatment technique, Liquid-phase microextraction can detect aimed compound in complex sample, with a small amount of organic solvent, little pollution. Because it takes extraction, purification and concentrated in one-step, requires no special equipment, has a low cost, microextraction has applied in the field of sample technique rapidly.Hollow semipermeable membrane, which is also used in hollow semipermeable membrane microextraction, used in the probe of microdialysis as it main material. We can combine two techniques together, to promote the performance of microdialysis. We do the evaluation of the recovery in different flow rate or in different time point by self-made microdialysis probes after made them successfully. The result shows self-made microdialysis has stable properties, good repeatability and can reach to a stable state in a short time.Then, combining the techniques of microdialysis and hollow semipermeable membrane microextraction together, using organic solvent as perfusate, we get a high concentrate of nonpolar drug in outlet perfusate. To the concentrate of nonpolar drug in polar solvent approach the limit of diction, we can enrichment the concentrate rapidly and continuously during a long time.We build up a new measuring method to detect the plasma protein binding ratio by this technique. According to the process of experiment, this method can get experiment data quickly and steadily, also can take multiple metering in a short period.At last, we take a pharmacokinetics experiment employ the technique of microdialysis combine with hollow semipermeable membrane microextraction. Using triamcinolone acetate cream as experimental drug, we figure out its pharmacokinetics characteristic in the rat’s skin. As microdialysis taking place in tissues, concentrate of drug was concentrated at the same time, so we can sample and analysis the concentrate of drug that used had to be detected by this method but easily now.