RESUMEN
A rapid and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was applied to investigate the permeability characteristics and transport mechanism of trihexyphenidyl hydrochloride (TH) in D-hanks with the Caco-2 cells model. Analytes were separated using an Zorbax Extend-Agilent C18 (1.8⯵m, 4.6â¯×â¯30â¯mm) column following a simple methanol precipitation treatment. The mobile phase consisted of methanol and water containing 0.1% formic acid, and the total gradient program time was 1.5â¯min. Method validation results showed TH was linear in 2-500â¯ng/mL (r2â¯>â¯0.99), and the lower limit of quantification (LLOQ) was 2⯵g/mL. The intra-run and inter-run precision (coefficient of variation, CV) was within 2.80%, and the accuracy (relative error, RE) was within ±11.10%. Stability of TH was evaluated in different storage conditions, including short-term I-III, long-term I-III, 2 and 4â¯h in the artificial gastrointestinal tract, respectively. There was no obvious interference between TH and internal standards (IS). With the established Caco-2 monolayer permeability model, Papp(AB) of TH was calculated as 46.29⯱â¯8.31â¯×â¯10-6â¯cm/s, and the efflux ratio (ER) value was calculated as 0.22, indicating a high permeability character of TH. The transmembrane transport of TH followed the concentration-dependent, temperature-independent, and energy-free manner. Collectively, these characteristics indicate that TH is a highly permeable drug and the transport mechanism is mainly via passive diffusion.
Asunto(s)
Trihexifenidilo/metabolismo , Células CACO-2 , Línea Celular Tumoral , Cromatografía Líquida de Alta Presión/métodos , Glicoesfingolípidos/metabolismo , Humanos , Límite de Detección , Permeabilidad , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/métodosRESUMEN
Ciklodol (trihexyphenidil)--the central and peripheral m-cholinoblocker is currently used with other antipsychotic drugs such as phenotiazines and tricycle antidepressants. For the purpose of simultaneous determination of ciklodol and diprazine, were selected two methods of analysis: Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC). During development of TLC method was studied the 10 visualizing system and 24 mobile systems. For individual or simultaneous determination of ciklodol and diprazine were recommended the following solvents' systems: 1. Toluene-acetone-ethanole-25%NH(4)OH (45:45: 7.5:2.5), 2. Hexane-ethyl acetate (15:5), 3. Chloroform-heptene-25%NH(4)OH (16:3:3), 4. Ethylacetate-hexane (10:10), 5. Acetonitrile-metanol (10:10) and 6.Heptene-chloroform-ethanol-25% NH(4)OH (5:10:3:1). As visualizing systems were chosen: Iodine vapors, blacklight (UV254) and reagent of FNP. Reagent of FNP gives colored spot just with diprazine and it is also could be used for separation of both objects in simultaneous analysis. Developed HPLC method of simultaneous determination of ciklodol and diprazine: like mobile phase is recommended: Acetonitril- 0.05M KH(2)PO4 (55:45) (v/v) +H(3)PO(4) (pH3.5), column EC250 x 4.6mm, with solid phase Nucleosil, flow rate 1ml/min, sample volume 40 microl. In given conditions, the retention time of ciklodol is 6.005min and diprazine 7.227min. Developed method of simultaneous determination and separation of ciklodol and diprazine in respective mixtures could be successfully applied as in the pharmaceutical, as well in the chemical-toxicological laboratories.
Asunto(s)
Antiparkinsonianos/metabolismo , Antagonistas de los Receptores Histamínicos H1/metabolismo , Prometazina/metabolismo , Trihexifenidilo/metabolismo , Antiparkinsonianos/economía , Cromatografía Líquida de Alta Presión/economía , Cromatografía en Capa Delgada/economía , Análisis Costo-Beneficio , Antagonistas de los Receptores Histamínicos H1/economía , Humanos , Prometazina/economía , Estándares de Referencia , Trihexifenidilo/economíaRESUMEN
A new technique for investigating drug-protein binding was developed employing capillary electrophoresis (CE) coupled with tris(2,2'-bipyridyl) ruthenium(II) [Ru(bpy)(3) (2+)] electrochemiluminescence (ECL) (CE-ECL) detection after equilibrium dialysis. Three basic drugs, namely pridinol, procyclidine and its analogue trihexyphenidyl, were successfully separated by capillary zone electrophoresis with end-column Ru(bpy)(3) (2+) ECL detection. The relative drug binding to human serum albumin (HSA) for each single drug as well as for the three drugs binding simultaneously was calculated. It was found that the three antiparkinsonian drugs compete for the same binding site on HSA. This work demonstrated that Ru(bpy)(3) (2+) CE-ECL can be a suitable technique for studying drug-protein binding.
Asunto(s)
Antiparkinsonianos/análisis , Electroforesis Capilar/métodos , Mediciones Luminiscentes/métodos , Albúmina Sérica/metabolismo , Antiparkinsonianos/metabolismo , Unión Competitiva , Humanos , Compuestos Organometálicos/análisis , Compuestos Organometálicos/química , Piperidinas/análisis , Piperidinas/metabolismo , Prociclidina/análisis , Prociclidina/metabolismo , Unión Proteica , Albúmina Sérica/química , Trihexifenidilo/análisis , Trihexifenidilo/metabolismoRESUMEN
An amnesic effect of anticholinergic drugs was previously described from several behavioral studies. We examined this effect induced by trihexyphenidyl and biperiden, clinically used in the parkinsonism and schizophrenic patients, by using passive avoidance tasks. Both of these drugs (0.1-10 mg/kg, s.c.) showed dose-dependent amnesic effects in the acquisition and retrieval phases. However, the effect induced by trihexyphenidyl was transient, whereas that of biperiden was long-lasting. To clarify the reason for the different duration of the amnesic activity, binding to the muscarinic receptor was examined. In the Scatchard analysis, trihexyphenidyl competed with [(3)H]quinuclidinyl benzilate ([(3)H]QNB) on the muscarinic receptor (showed increased K(d) and unchanged B(max) value), while biperiden decreased [(3)H]QNB binding (B(max) value) significantly. Furthermore, in an exchange assay for receptor inactivation, trihexyphenidyl binding to muscarinic receptors was exchanged by [(3)H]QNB completely, but biperiden decreased the exchangeable binding of [(3)H]QNB in a dose dependent manner (0.1-100 nM). These results suggested that the binding of trihexyphenidyl and biperiden to muscarinic receptor might be completely reversible and partially irreversible, respectively, whereas the K(i) values of these two drugs were similar. In conclusion, this difference in binding property may explain the difference in the time-course of the amnesic effect induced by trihexyphenidyl and biperiden.
Asunto(s)
Amnesia/inducido químicamente , Biperideno/metabolismo , Encéfalo/metabolismo , Antagonistas Colinérgicos/metabolismo , Receptores Muscarínicos/metabolismo , Trihexifenidilo/metabolismo , Animales , Reacción de Prevención/efectos de los fármacos , Unión Competitiva , Biperideno/farmacología , Corteza Cerebral/metabolismo , Antagonistas Colinérgicos/farmacología , Electrochoque , Masculino , Membranas/metabolismo , Dolor/fisiopatología , Quinuclidinil Bencilato/metabolismo , Ratas , Ratas Wistar , Retención en Psicología/efectos de los fármacos , Factores de Tiempo , Trihexifenidilo/farmacologíaRESUMEN
A sensitive and specific assay for the simultaneous quantification of trihexyphenidyl and its hydroxylated metabolite in plasma and urine is described. The method is based on the extraction of the drugs with an organic solvent and separation on a 3% OV-17 Chromosorb Q column in a gas chromatograph equipped with a nitrogen-phosphorus detector. The procedure employs SKF 525 A as the internal standard and requires no derivatization. The detection limit was found to be 2 ng/mL for trihexyphenidyl and 1 ng/mL for its metabolite. The precision of the assay procedure for both compounds is about 4 to 7%.
Asunto(s)
Trihexifenidilo/análogos & derivados , Trihexifenidilo/análisis , Cromatografía de Gases/métodos , Humanos , Nitrógeno , Fósforo , Trihexifenidilo/metabolismoRESUMEN
The selectivity profiles of the muscarinic receptor antagonists dicyclomine and trihexyphenidyl have been examined in binding and functional studies and compared with those of pirenzepine and atropine. Dicyclomine, trihexyphenidyl and pirenzepine demonstrated the highest affinity for the M1 muscarinic receptor subtype as revealed in competition experiments against [3H]-pirenzepine labelling of cortical membranes. Their affinity values lay in a narrow range (3.7-14 nM) approaching that of atropine (1.6 nM). Competition experiments against [3H]-N-methylscopolamine in cardiac and glandular (salivary) membranes revealed differences between the drugs examined. Dicyclomine, trihexyphenidyl and pirenzepine displayed low affinity for the cardiac and intermediate affinity for the glandular receptors. Thus, the drugs appeared to discriminate between the M1 (cortical) and the peripheral muscarinic subtypes (cardiac and glandular). However, atropine displayed similar affinities for either subtype with IC50s varying only slightly (1.6-4.6 nM). The rank order of selectivity was: pirenzepine greater than dicyclomine greater than trihexyphenidyl greater than atropine. Mirroring the binding data, pirenzepine, dicyclomine and trihexyphenidyl showed a tenfold greater ability at inhibiting M1-receptor mediated ganglionic responses (McN A-343 pressor effect in pithed rats and nictitating membrane contraction in cats) than at inhibiting peripheral muscarinic responses in the heart and cardiovascular smooth muscle (vagal bradycardia in rats and cats and vagally-induced vasodilatation in cats). The muscarinic antagonists so far examined can be categorized into two groups. Trihexyphenidyl, dicyclomine and pirenzepine, included in one group, are characterized by a higher affinity for the neuronal (M1) muscarinic receptor, hence they antagonize functional responses mediated by the M1 subtype. Atropine, a member of the other group, shows essentially no selectivity. 6 Differentiation of M1 and peripheral muscarinic receptor subtypes appears to be a property not confined to tricyclics such as pirenzepine but shared by diverse chemical structures. Both trihexyphenidyl and dicyclomine appear to be useful pharmacological tools in the classification of muscarinic receptor subtypes.
Asunto(s)
Ácidos Ciclohexanocarboxílicos/metabolismo , Diciclomina/metabolismo , Receptores Muscarínicos/metabolismo , Trihexifenidilo/metabolismo , Cloruro de (4-(m-Clorofenilcarbamoiloxi)-2-butinil)trimetilamonio/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Estado de Descerebración , Diciclomina/farmacología , Estimulación Eléctrica , Técnicas In Vitro , Masculino , Pirenzepina/metabolismo , Ratas , Ratas Endogámicas , Receptores Muscarínicos/efectos de los fármacos , Trihexifenidilo/farmacología , Nervio Vago/fisiologíaRESUMEN
The muscarinic cholinergic receptors in the urinary bladders of man, guinea pig, rat and rabbit were studied by means of a receptor binding technique, with l-quinuclidinyl [phenyl 4-3H]benzilate, (-)3H-QNB, as radioligand. The potential role of the receptors in the supersensitivity of the rat bladder to muscarinic agonists, following parasympathetic denervation, hypertrophy and urinary diversion, was also investigated. In addition, the binding of various unlabelled antimuscarinic drugs in the guinea pig bladder was compared to that in other tissues in order to study the putative muscarinic receptor subtypes, commonly referred to as M1 and M2. According to this classification the putative M1 receptors prevail in discrete areas of the brain, whereas the M2-receptors predominate in peripheral tissues, such as the exocrine glands and smooth muscles. The receptor density (but not the qualitative properties of the receptors) in the bladder differed between the species. The affinities of various antimuscarinic drugs were virtually identical in the guinea pig and human bladders. In both species, the binding data were found to correlate with functional in vitro data. In the rat bladder, the receptor density was increased after denervation but decreased, below control values, when the denervation was combined with urinary diversion. A decrease was also found after urinary diversion of innervated bladders, whereas the receptor density was unaffected by hypertrophy. These results suggest that the receptors are not involved in the development of supersensitivity and that the receptor levels may be influenced by the functional state of the bladder. Binding studies with classical muscarinic antagonists indicated that the receptors in the guinea pig bladder are indistinguishable from those in the ileum, heart, parotid gland and cerebral cortex. However, four drugs--namely, oxybutynin, dicyclomine, benzhexol and pirenzepine had a much higher affinity for the receptors in the parotid gland and cortex than for those in the other tissues. Moreover, dicyclomine and benzhexol, like pirenzepine, seemed in the cortex to distinguish between two classes of sites exhibiting high and low affinity. The high affinity sites could be selectively labelled with 3H-benzhexol. The ability of oxybutynin, dicyclomine, benzhexol and pirenzepine to discriminate between the receptors in the parotid gland and those in smooth muscle provides further evidence that the M1/M2 concept is inaccurate. The present data indicate that there may be three classes of muscarinic antagonist binding sites.
Asunto(s)
Receptores Muscarínicos/fisiología , Vejiga Urinaria/fisiología , Adulto , Anciano , Animales , Carbacol/farmacología , Corteza Cerebral/metabolismo , Desnervación , Cobayas , Humanos , Hipertrofia , Íleon/metabolismo , Cinética , Persona de Mediana Edad , Contracción Muscular/efectos de los fármacos , Miocardio/metabolismo , Sistema Nervioso Parasimpático/fisiología , Parasimpatolíticos/metabolismo , Parasimpatolíticos/farmacología , Glándula Parótida/metabolismo , Quinuclidinil Bencilato/metabolismo , Conejos , Ratas , Receptores Muscarínicos/clasificación , Receptores Muscarínicos/efectos de los fármacos , Especificidad de la Especie , Trihexifenidilo/metabolismo , Tritio , Vejiga Urinaria/inervación , Vejiga Urinaria/patología , Derivación UrinariaAsunto(s)
Receptores Muscarínicos/metabolismo , Trihexifenidilo/metabolismo , Animales , Unión Competitiva , Química Encefálica , Epitelio/metabolismo , Técnicas In Vitro , Mucosa Intestinal/metabolismo , Masculino , Músculo Liso/metabolismo , Miocardio/metabolismo , N-Metilescopolamina , Quinuclidinil Bencilato/metabolismo , Ratas , Ratas Endogámicas , Receptores Muscarínicos/clasificación , Derivados de Escopolamina/metabolismoRESUMEN
Alpha1-acid glycoprotein (alpha1-AG) was purified from human sera, and its binding properties with respect to psychotropic drugs were examined by equilibrium dialysis methods in order to clarify the specificity of binding. Radioactive imipramine, a tricyclic antidepressant, was used as the primary ligand. Other drugs, representative of different classes, were tested as potential inhibitors of the alpha1-AG-imipramine binding. The K(a) for imipramine was 2.8 x 10(5) (+/- 0.8) M(-10 (mean +/- S.D.). Chlorpromazine, fluphenazine, thioridazine, loxapine and thiothixene, which are antipsychotic drugs, were competitive inhibitors of imipramine binding, and their K(a) values were in the same range. Propranolol, haloperidol and diazepam were also competitive inhibitors but their affinities were lower. Molindone, an indolic antipsychotic, when tested at the same concentrations as the other drugs, did not affect imipramine binding. Trihexyphenidyl, an anti-Parkinson drug, was a potent but noncompetitive inhibitor. These data identify the antidepressant and major tranquilizer drugs that exhibit high affinity for alpha1-AG and indicate that alpha1-AG may account for 40 per cent of total imipramine bound in serum. Since in psychiatric clinical practice two drugs are frequently administered together, possible competitive effects are discussed as well as the potential role of alpha1-AG in psychiatric illness.
Asunto(s)
Imipramina/metabolismo , Orosomucoide/metabolismo , Psicotrópicos/metabolismo , Unión Competitiva/efectos de los fármacos , Clorpromazina/metabolismo , Clorpromazina/farmacología , Flufenazina/metabolismo , Flufenazina/farmacología , Humanos , Imipramina/farmacología , Cinética , Loxapina/metabolismo , Loxapina/farmacología , Molindona/metabolismo , Molindona/farmacología , Unión Proteica/efectos de los fármacos , Psicotrópicos/clasificación , Psicotrópicos/farmacología , Tioridazina/metabolismo , Tioridazina/farmacología , Tiotixeno/metabolismo , Tiotixeno/farmacología , Trihexifenidilo/metabolismo , Trihexifenidilo/farmacologíaRESUMEN
The investigation of the metabolism of the antiparkinson drugs trihexyphenidyl (1), pridinol (2) and biperiden (3) revealed a graduate tendency for hydroxylation in the different structural elements: If alicyclic, saturated heterocyclic and aromatic ring systems are present in one compound like in 1, the alicyclic ring system is attacked predominately. The amount of metabolites with hydroxy-groups in the saturated heterocyclic ring is much lower, and no hydroxylation takes place in the aromatic ring. In drugs without alicyclic ring systems like 2 the saturated heterocyclus is attacked preferentially, but also some phenolic metabolites are formed. Consequently the following arrangement of falling hydroxylation-tendency can be established: Formula: see text. Probably this arrangement is of common validity and therefore a prediction on the hydroxylation-tendency of other compounds seems to be possible.
Asunto(s)
Antiparkinsonianos/metabolismo , Adulto , Biotransformación , Biperideno/metabolismo , Humanos , Hidroxilación , Masculino , Espectrometría de Masas , Piperidinas/metabolismo , Relación Estructura-Actividad , Trihexifenidilo/metabolismoRESUMEN
1. Benzhexol and three of its metabolites excreted in urine in man have been investigated by g.l.c.--mass spectrometry. 2. Three isomeric hydroxylated metabolites were identified as the 1-(hydroxycyclohexyl)-1-phenyl-3-piperidinopropan-1-ols. 3. The amounts of benzhexol and its identified metabolites have been semiquantitatively determined after a single oral dose in two healthy adults. Approx. 56% of the dose was excreted as the hydroxylated metabolites. The levels of benzhexol excreted were too low to be measured by the techniques used.
Asunto(s)
Trihexifenidilo/metabolismo , Adulto , Humanos , Hidroxilación , Espectrometría de Masas , Trihexifenidilo/orinaRESUMEN
The extent of the binding of [3H]propylbenzilylcholine mustard (3H-PrBCM) to muscarinic receptors in longitudinal muscle strips from guinea-pig small intestine is increased by nearly 50% when the strips are preexposed to distilled water before measurement of 3H-PrBCM binding in Krebs-Henseleit solution. The apparent rate constant for 3H-PrBCM-receptor complex formation is more than double that of intact strips. The curves for the inhibition of 3H-PrBCM binding by methylatropinium bromide in normal and treated strips are superimposable, but, in contrast, distilled water pretreatment shifts the inhibition curve for carbachol to lower concentrations by a factor of 5-6. The inhibition curve for methylfurmethide is also shifted, by a factor of approximately 4, but the effect on the curve for hexyltrimethylammonium (C6TMA) is slight. The relative inhibition produced by benzhexol in the two preparations was variable. Comparison of the rate of equilibration of benzhexol with muscarinic receptors in intact and in distilled water pretreated muscle indicates that this inconsistency is unlikely to be due to incomplete equilibration.