20.500.12556/RUL-121063 Bioanalizno in farmakokinetično vrednotenje pregabalina Bioanalysis and pharmacokinetics of pregabalin Pregabalin je strukturni analog inhibitornega nevrotransmiterja γ-aminobutirne kisline (GABA) in deluje na centralni živčni sistem. Uporablja se kot dodatno zdravljenje pri epilepsiji, za zdravljenje nevropatske bolečine in pri anksioznih motnjah. V območju priporočenih dnevnih odmerkov ima linearno farmakokinetiko in predvidljiv odnos med odmerkom in učinkom. Izločanje poteka predvsem preko ledvic, zato je potrebna prilagoditev odmerka pri bolnikih z zmanjšanim ledvičnim delovanjem. Namen magistrske naloge je bil določiti plazemske koncentracije pregabalina po peroralni aplikaciji zdravila na tešče in na osnovi izmerjenih koncentracij izračunati individualne farmakokinetične parametre. Plazemske koncentracije pregabalina smo določili 12 zdravim moškim prostovoljcem s tekočinsko kromatografijo visoke ločljivosti in uporabo fluorescenčnega detektorja. Vzorce smo ustrezno pripravili z ekstrakcijo na trdih nosilcih. Pregabalin ne absorbira svetlobe v ultravijoličnem in vidnem območju, zato smo ekstrahirane vzorce derivatizirali s 7-kloro-4-nitrobenzofurazanom (NBD-Cl), ki tvori fluorescenčen derivat z aminsko skupino pregabalina. Rezultate smo delno validirali po smernicah Ameriške agencije za hrano in zdravila za bioanalizne metode. Metoda je linearna v območju 0,375-30 μg/mL, točna (100,4-107,9 %) in ponovljiva (0,60-5,17 %). Izmerjenim plazemskim koncentracijam pregabalina smo z od modela neodvisnim pristopom, neposredno iz grafa odvisnosti plazemskih koncentracij od časa, izračunali osnovne farmakokinetične parametre, kot so maksimalna koncentracija pregabalina v plazmi (8,25 μg/mL), čas v katerem se doseže ta koncentracija (0,875 h), hitrostna konstanta eliminacije (0,1102 h-1) in površina pod plazemsko krivuljo ekstrapolirana do neskončnosti (43,27 μg×h/mL). S pomočjo farmakokinetičega modeliranja smo določili, da ima pregabalin dvoprostorno farmakokinetiko. Tipična vrednost hitrostne konstante absorpcije pregabalina je 0,247 h-1, navideznega volumna porazdelitve 36,9 L in očistka 126,7 mL/min. Slednji je v direktni medsebojni odvisnosti z očistkom kreatinina, ki ga v klinični praksi uporabljamo za oceno glomerulne filtracije. V enačbi premice ClPRG = 0,72×Clcr – 0,23, ki ponazarja povezavo med očistkom pregabalina (ClPRG) in očistkom kreatinina (Clcr), odsek na ordinatni osi blizu vrednosti 0 nakazuje, da je sistemski metabolizem pregabalina zanemarljiv in v celoti odvisen od ledvične funkcije. Pregabalin is a structural analogue of inhibitory neurotransmitter γ-aminobutyric acid (GABA) and acts on the central nervous system. It is used for the additional treatment of epilepsy, for the treatment of neuropathic pain and anxiety disorders. Within the range of recommended daily doses it has a linear pharmacokinetics and predictable relationship between the dose and effect. Secretion takes place mostly in the kidneys, so with the patients who have a decreased renal function the adaption of the dose is needed. The aim of the master’s dissertation was to determine plasma pregabalin concentrations after the oral administration of the medicine under fasting conditions and, on the basis of the measured concentrations, calculate individual pharmacokinetic parameters. Plasma pregabalin concentrations of 12 healthy male volunteers were determined. We used a high performance fluid chromatography method and fluorescence detector. Samples were prepared using solid phase extraction method. Since pregabalin does not absorb visible and ultraviolet light, the extracted samples were derivatized with 7-chloro-4-nitrobenzofurazan (NBD-Cl), which forms a fluorescent derivative with the amino group of pregabalin. The results were partially validated according to the US Food and Drug Administration’s guidelines for bioanalytical methods. The method was linear within the range of 0.375-30 μg/mL, accurate (100.4-107.9 %) and precise (0.60-5.17 %). With the model-independent approach and directly from the graph showing the dependence of plasma concentration and time, we have calculated the basic pharmacokinetic parameters for the measured pregabalin concentrations in plasma samples, such as maximum concentration of pregabalin in plasma (8.25 μg/mL), time in which this concentration is reached (0.875 h), elimination rate constant (0.1102 h-1) and the area under the plasma curve extrapolated to infinite time (43.27 μg×h/mL). Using pharmacokinetic modelling, we determined that pregabalin follows a two-compartment pharmacokinetic model. A typical value of the pregabalin absorption rate constant is 0.247 h-1, of the apparent volume of distribution 36.9 L and of clearance 126,7 mL/min. The latter and the creatinine clearance, which clinical practice uses for the estimation of glomerular filtration rate, are directly mutually interdependent. In straight line equation y = 0.72x – 0.23, representing the connection between pregabalin clearance and creatinine clearance, the y-axis intercept near value 0 indicates that systemic metabolism of pregabalin is negligible and fully dependent on renal function. pregabalin modeliranje tekočinska kromatografija visoke ločljivosti farmakokinetična analiza neželeni učinki pregabalina protiepeileptične učinkovine pregabalin epilepsy high performance fluid chromatography pharmacokinetic analysis modelling true false false [N. Novak] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2020-09-29 13:21:54 2020-09-29 13:21:55 2022-09-01 04:01:22 0000-00-00 00:00:00 2015 0 Ljubljana 2015 Ljubljana XI, 52 f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 543.544:615.015(043.3) 3991153 MAG_Novak_Nina_2015.pdf MAG_Novak_Nina_2015.pdf 1 EA739BA674C40BF5591FF58B75A80307 75c681192bc3aa28eb2776cb62ccd17ee480dfc23a425b010ee5afd5c8c017dd 3745f494-a1ba-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=135922 Fakulteta za farmacijo 0 0 0