Quantitative analysis of phenibut in rat brain tissue extracts by liquid chromatography–tandem mass spectrometry

Abstract

Phenibut (3-phenyl-4-aminobutyric acid) is a gamma-aminobutyric acid mimetic drug, which is used clinically as a mood elevator and tranquilizer. In the present work, a rapid, selective and sensitive liquid chromatography-tandem mass spectrometry method for quantification of phenibut in biological matrices has been developed. The method is based on protein precipitation with acidic acetonitrile followed by isocratic chromatographic separation using acetonitrile-formic acid (0.1% in water; 8:92, v/v) mobile phase on a reversed-phase column. Detection of the analyte was performed by electrospray ionization mass spectrometry in multiple reaction monitoring mode with the precursor-to-product ion transition m/z 180.3 --> m/z 117.2. The calibration curve was linear over the concentration range 50-2000 ng/mL. The lower limit of quantification for phenibut in rat brain extracts was 50 ng/mL. Acceptable precision and accuracy were obtained over the whole concentration range. The validated method was successfully applied in a pharmacological study to analyze phenibut concentration in rat brain tissue extract samples.

A review of sample preparation methods for quantitation of small-molecule analytes in brain tissue by liquid chromatography tandem mass spectrometry (LC-MS/MS)

“…17,28,44,57,60,61,66 Among all these homogenization methods, rotating blade is the most commonly used one for brain tissue samples, due to its low cost and easy operation. 19,21,22,31,36,38,40,41,43,75,77,79,81,[84][85][86]90 However, extra attention needs to be paid to the cleanliness of the blades, otherwise contamination can be a possible issue with the traditional rotating blade homogenizer. Bead beating 15,55 and ultrasonication 8,[24][25][26]39 are both newer techniques that have the advantages of higher efficiency, higher throughput as well as lower chance of contamination when compared to the traditional grinding or rotating blade homogenization techniques, making these two new techniques more popular in recent studies.…”

“…Due to the simplicity of the method, water has been the most commonly used homogenization media. 13,14,19,21,22,35,40,41,43,49,50,57,70,71,74,75,77,80,81,[84][85][86]88,90 In these methods, to one unit weight of brain tissue, at least one to two volumes of ice-cold water is add for homogenization, forming a homogeneous suspension of diluted brain tissue. In some studies, more water is added to yield a more diluted brain homogenate, which can be treated similarly to plasma or even serum samples in sample preparation, making it possible to use the same method for multiple sample species.…”

“…It is capable of simple and fast treatment of biological samples, and can be considered as the most widely used sample preparation method. 9,10,13,15,16,[19][20][21][22]24,25,[29][30][31][34][35][36][37][38][39]41,42,46,48,49,[51][52][53]55,57,58,[60][61][62][63][66][67][68]72,74,[76][77][78][79][80]87,88,90,92,94 Proteins are large biological molecules that are composed of amino acids linked by peptide bonds. Under physiological conditions, a solub...…”

Safety and Tolerability of the Anxiolytic and Nootropic Drug Phenibut: A Systematic Review of Clinical Trials and Case Reports

“…It was shown that after intraperitoneal administration in mice, the acute median lethal dose (LD 50 ) of phenibut was 900 mg/kg [2], while the median effective dose (ED 50 ) of phenibut was 10 mg/ kg [6]. It was shown that phenibut crossed the blood-brain barrier, that it was present in rat liver, kidney, and brain tissue, and that it was excreted unmetabolized in the urine by glomerular filtration following intravenous administration to rabbits, rats, cats, and dogs [7]. Two studies reported dopamine metabolism activation after the administration of phenibut in rats and mice [8,9]; however, these findings have not been confirmed in vivo.…”

Repositioning of Omarigliptin as a once-weekly intranasal Anti-parkinsonian Agent

“…Determination of drugs in animal brain tissue is common in the literature 48 – 58 to check their crossing of BBB. Various extraction techniques were employed for extraction of drugs either from brain homogenate alone 50 , 51 or from both animal plasma & brain extract 50 – 56 including direct precipitation 48 – 51 ; liquid-liquid extraction 52 – 56 , solid phase extraction 57 & QuEChERS based approach 58 . Moreover, direct precipitation was also used for simultaneous extraction of eight neurotransmitters from brain tissue 59 .…”