Stir bar sorptive extraction for central nervous system drugs from biological fluids

A review with 75 references is presented that deals with the reported methods for analysis of some important central nervous system (CNS) drugs in biological fluids utilizing stir bar sorptive extraction (SBSE) technique covering the years from 2000 to 2008. The theoretical aspects of SBSE, as well as an significant number of applications have been published, showing the advantages of this technique over the classical extraction techniques (liquid–liquid extraction (LLE) and solid-phase extraction (SFE). In this review, recent SBSE developments and a focus on the development of new instrumental approaches and sorbent phases are presented.     

Simple and sensitive high-performance liquid chromatography method for the quantitation of indinavir in rat plasma and central nervous system

A simple and sensitive RP-HPLC method using UV detection (215 nm) was developed for the determination of indinavir concentrations in rat plasma, cerebrospinal fluid (CSF), and brain tissue homogenates. Biological samples were processed using a combination of acid pretreatment and liquid-liquid extraction with verapamil used as the internal standard. This method produced a linear response throughout the indinavir concentration range of 0.05-30 microM in plasma and 0.05-2.5 microM in CSF and brain with a LOD of 12.5 nM for plasma and CSF, and 6.25 nM for brain homogenate. Due to its high sensitivity, this assay is particularly useful for the quantitative determination of indinavir concentrations in brain and CSF.     

Biochemistry and function of biogenic amines in the central nervous system

A number of amines are of the utmost importance to the normal function of the nervous system; numerous relationships also exist between certain diseases of the nervous system and the metabolism of these amines. Noradrenaline, serotonin, and histamine are taken as examples to offer some idea of the possibilities and methods of biochemical research that help to elucidate the physiological and pathological processes in the nervous system. The article shows that our knowledge of the functioning of the nervous system, even in a field that has been studied as thoroughly as the transmission of nerve stimuli at synapses, is still in its infancy.     

Determination of neurotransmitter amino acids in mouse central nervous system by CE–LIF

An MEKC method with LIF detection has been developed for the determination of seven neurotransmitter amino acids (NAAs) using 1,3,5,7‐tetramethyl‐8‐(N‐hydroxysuccinimidyl butyric ester)difluoroboradiaza‐S‐indacene as the labeling reagent. After derivatization at room temperature for 30 min, the seven target NAAs including glycine, alanine, γ‐aminobutyric acid, taurine, glutamine, glutamic acid, and aspartic acid were separated in running buffer, which consisted of 70 mM pH 4.00 H₃PO₄/Na₃PO₄ buffer, 5.5 mM cetyltrimethyl ammonium bromide and 20% v/v acetonitrile within 17 min. The LODs were 2 ～ 14 × 10^?10 M without interference from other coexisting amino acids. The proposed method has been applied to the analysis of NAAs in the central nervous systems of healthy mice and those with Alzheimer's disease with recoveries of 92–104%.     

Potential applications of polymers in the delivery of drugs to the central nervous system

There is increased need and increased efforts being placed on the discovery of new therapeutic agents effective against central nervous system diseases. Concomitant with the central nervous system drug discovery efforts, there is a need for improved methods for delivering drugs to the brain. The present report reviews the general strategies that have been employed to improve the delivery of drugs across the blood–brain and blood–cerebral spinal fluid barriers, and discusses the potential applications of polymeric drug delivery systems for enhancing the delivery of drugs to the brain.