RESUMEN
Antibody-like biopharmaceuticals cross the placenta by utilizing existing transport pathways (e.g., FcRn receptor). There are limited data evaluating this transfer during organogenesis in any species. Understanding placental transfer of antibody-like biopharmaceuticals can help to predict risk of developmental toxicity across species, including humans. To complement previously published placental transfer data in the rat with humanized IgGΔ2 (hIgG2), the timing and magnitude of transfer in the cynomolgus monkey and embryo/fetal biodistribution of maternally administered 125 I-radiolabeled hIgG2 was quantified on gestation days (GD) 35, 40, 50, 70, and 140 using gamma counting and whole body autoradiography 24 hr following intravenous injection. Chorioallantoic placental tissues were collected at all time points for Western Blot analysis with anti-FcRn antibody. Maternally administered 125 I-hIgG2 was found in embryo/fetal tissues at all time points, including organogenesis. Embryo/fetal plasma 125 I-hIgG2 concentration increased during gestation, but only slightly up to GD 70 in embryo/fetal tissues, with hIgG2 tissue concentrations generally similar between GD70 and 140. The embryo/fetal:maternal 125 I-hIgG2 plasma concentration ratio was approximately 2.3 fold higher on GD 140, in comparison to ratios on GD 40. Importantly, placental FcRn protein expression was confirmed at all timepoints. These data demonstrate placental transfer of hIgG2 in a nonhuman primate model, and at levels comparable to the rat model, raising the potential for adverse developmental outcomes by direct antibody binding to biological targets.
Asunto(s)
Inmunoglobulina G/inmunología , Intercambio Materno-Fetal/inmunología , Placenta/inmunología , Animales , Anticuerpos Monoclonales/metabolismo , Embrión de Mamíferos/metabolismo , Femenino , Feto/metabolismo , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/metabolismo , Radioisótopos de Yodo/metabolismo , Macaca fascicularis/inmunología , Macaca fascicularis/metabolismo , Intercambio Materno-Fetal/fisiología , Organogénesis/inmunología , Organogénesis/fisiología , Embarazo , Distribución Tisular/inmunologíaRESUMEN
Quantitative whole-body autoradiography was used to assess the distribution and tissue penetration of isavuconazole in rats following single and repeated oral-dose administration of radiolabeled isavuconazonium sulfate, the prodrug of isavuconazole. Following a single-dose administration of radiolabeled isavuconazonium sulfate (labeled on the active moiety), radioactivity was detectable within 1 h postdose in 56 of 65 tissue/fluid specimens. The highest maximum concentrations (Cmax) were observed in bile and liver (66.6 and 24.7 µg eq/g, respectively). The lowest Cmax values were in bone and eye lens (0.070 and 0.077 µg eq/g, respectively). By 144 h postdose, radioactivity was undetectable in all tissues/fluids except liver (undetectable at 336 h) and adrenal gland tissues (undetectable at 672 h). Following daily administration for up to 21 days, 1-h-postdose Cmax values were the highest on or before day 14 in all except seven tissues/fluids, of which only rectum mucosa and small intestine mucosa had Cmax values >25% higher than all other 1-h-postdose values. For 24-h-postdose Cmax values, only large intestine, large intestine mucosa, and urine had the highest Cmax values at day 21. The penetration of single oral doses of unlabeled isavuconazole (25 mg/kg of body weight isavuconazonium sulfate) and voriconazole (50 mg/kg) into rat brain (assessed using liquid chromatography-tandem mass spectrometry) was also compared. Brain concentration/plasma concentration ratios reached approximately 1.8:1 and 2:1, respectively. These data suggest that isavuconazole penetrates most tissues rapidly, reaches a steady state in most or all tissues/fluids within 14 days, does not accumulate in tissues/fluids over time, and achieves potentially efficacious concentrations in the brain.
Asunto(s)
Encéfalo/metabolismo , Nitrilos/farmacocinética , Piridinas/farmacocinética , Triazoles/farmacocinética , Voriconazol/farmacocinética , Administración Oral , Glándulas Suprarrenales/metabolismo , Animales , Autorradiografía , Bilis/metabolismo , Huesos/metabolismo , Mucosa Intestinal/metabolismo , Infecciones Fúngicas Invasoras/tratamiento farmacológico , Cristalino/metabolismo , Hígado/metabolismo , Masculino , Nitrilos/metabolismo , Profármacos/análisis , Profármacos/metabolismo , Piridinas/metabolismo , Ratas , Ratas Long-Evans , Ratas Sprague-Dawley , Ratas Wistar , Distribución Tisular , Triazoles/metabolismo , Voriconazol/metabolismoRESUMEN
1. The metabolism, pharmacokinetics, excretion and tissue distribution of a hepatitis C NS3/NS4 protease inhibitor, faldaprevir, were studied in rats following a single 2 mg/kg intravenous or 10 mg/kg oral administration of [(14)C]-faldaprevir. 2. Following intravenous dosing, the terminal elimination t1/2 of plasma radioactivity was 1.75 h (males) and 1.74 h (females). Corresponding AUC0-∞, CL and Vss were 1920 and 1900 ngEq · h/mL, 18.3 and 17.7 mL/min/kg and 2.32 and 2.12 mL/kg for males and females, respectively. 3. After oral dosing, t1/2 and AUC0-∞ for plasma radioactivity were 1.67 and 1.77 h and 11 300 and 17 900 ngEq · h/mL for males and females, respectively. 4. In intact rats, ≥90.17% dose was recovered in feces and only ≤1.08% dose was recovered in urine for both iv and oral doses. In bile cannulated rats, 54.95, 34.32 and 0.27% dose was recovered in feces, bile and urine, respectively. 5. Glucuronidation plays a major role in the metabolism of faldaprevir with minimal Phase I metabolism. 6. Radioactivity was rapidly distributed into tissues after the oral dose with peak concentrations of radioactivity in most tissues at 6 h post-dose. The highest levels of radioactivity were observed in liver, lung, kidney, small intestine and adrenal gland.
Asunto(s)
Oligopéptidos/farmacocinética , Inhibidores de Proteasas/farmacocinética , Tiazoles/farmacocinética , Administración Oral , Ácidos Aminoisobutíricos , Animales , Bilis , Biotransformación , Radioisótopos de Carbono/análisis , Heces , Femenino , Inyecciones Intravenosas , Leucina/análogos & derivados , Masculino , Prolina/análogos & derivados , Quinolinas , Ratas , Ratas Long-Evans , Ratas Sprague-Dawley , OrinaRESUMEN
Nanostructure initiator mass spectrometry (NIMS) is a recently introduced matrix-free desorption/ionization platform that requires minimal sample preparation. Its application to xenobiotics and endogenous metabolites in tissues is demonstrated, where clozapine and N-desmethylclozapine were observed from mouse and rat brain sections. It has also been applied to direct biofluid analysis where ketamine and norketamine were observed from plasma and urine. Detection of xenobiotics from biofluids was made even more effective using a novel NIMS on-surface extraction method taking advantage of the hydrophobic nature of the initiator. Linear response and limit of detection were also evaluated for xenobiotics such as methamphetamine, codeine, alprazolam, and morphine, revealing that NIMS can be used for quantitative analysis. Overall, our results demonstrate the capacity of NIMS to perform sensitive, simple, and rapid analyses from highly complex biological tissues and fluids.
Asunto(s)
Nanoestructuras , Xenobióticos/análisis , Métodos Analíticos de la Preparación de la Muestra , Animales , Encéfalo/citología , Clozapina/análogos & derivados , Clozapina/análisis , Clozapina/sangre , Clozapina/orina , Ketamina/análisis , Ketamina/metabolismo , Masculino , Espectrometría de Masas , Ratones , Ratones Endogámicos BALB C , Nicotina/análisis , Nicotina/metabolismo , Ratas , Saliva/química , Xenobióticos/sangre , Xenobióticos/orinaRESUMEN
Disposition of lasofoxifene (LAS; 6-phenyl-5-[4-(2-pyrrolidin-1-yl-ethoxy)-phenyl]-5,6,7,8-tetrahydro-naphthalen-2-ol. tartrate) was investigated in rats and monkeys after oral administration of a single oral dose of [(14)C]LAS. Total mean recoveries of the radiocarbon were 96.7 and 94.3% from rats and monkeys, respectively. The major route of excretion in both species was the feces, and based on a separate study in the bile duct-cannulated rat, this likely reflects excretion in bile rather than incomplete absorption. Whole-body autoradioluminography suggested that [(14)C]LAS radioequivalents distributed rapidly in the rat with most tissues achieving maximal concentrations at 1 h. Half-life of radioactivity was longest in the uvea (124 h) and shortest in the spleen ( approximately 3 h). LAS was extensively metabolized in both rats and monkeys because no unchanged drug was detected in urine and/or bile. Based on area under the curve((0-24)) values, >78% of the circulating radioactivity was due to the metabolites. A total of 22 metabolites were tentatively identified by liquid chromatography-tandem mass spectrometry. Based on the structures of the metabolites, six metabolic pathways of LAS were identified: hydroxylation at the tetraline ring, hydroxylation at the aromatic ring attached to tetraline, methylation of the catechol intermediates by catechol-O-methyl transferase, oxidation at the pyrrolidine ring, and direct conjugation with glucuronic acid and sulfuric acid. LAS and its glucuronide conjugate (M7) were the major circulating drug-related moieties in both rats and monkeys. However, there were notable species-related qualitative and quantitative differences in the metabolic profiles. The catechol (M21) and its sulfate conjugate (M10) were observed only in monkeys, whereas the glucuronide conjugate of the methylated catechol (M8) and hydroxy-LAS (M9) were detected only in rats.
Asunto(s)
Moduladores de los Receptores de Estrógeno/farmacocinética , Pirrolidinas/farmacocinética , Tetrahidronaftalenos/farmacocinética , Animales , Bilis/metabolismo , Cromatografía Líquida de Alta Presión , Moduladores de los Receptores de Estrógeno/sangre , Moduladores de los Receptores de Estrógeno/orina , Heces/química , Femenino , Macaca fascicularis , Masculino , Espectrometría de Masas/métodos , Pirrolidinas/sangre , Pirrolidinas/orina , Ratas , Ratas Sprague-Dawley , Tetrahidronaftalenos/sangre , Tetrahidronaftalenos/orina , Distribución TisularRESUMEN
The metabolism and disposition of 4-[4-(4-fluorophenoxy)-benzenesulfonylamino]tetrahydropyran-4-carboxylic acid hydroxyamide (CP-544439), a selective inhibitor of matrix metalloproteinase-13, was investigated in rats and dogs following oral administration of [(14)C]CP-544439. Both species showed quantitative recovery of the radiolabel, and feces was the major route of excretion. Whole-body autoradioluminography study in rats suggested distribution of CP-544439 in all tissues except central nervous system. The radiolabel was rapidly eliminated from most tissues except the periodontal ligament. Metabolism of CP-544439 was extensive in both species. Only 8.4 and 1.5% of the total dose constituted unchanged CP-544439 in the rat and dog, respectively. Similarly, pharmacokinetic analysis of [(14)C]CP-544439 and unchanged CP-544439 indicated that the exposure of the parent drug was 16 and 6.5% of the total radioequivalents in rat and dog, respectively. Metabolic profiling revealed that CP-544439 was primarily metabolized via glucuronidation, reduction, and hydrolysis. Glucuronidation was the primary route of metabolism in dogs, whereas reduction of the hydroxamate moiety was the major pathway in rats. Human plasma and urine obtained from a dose escalation study in healthy human volunteers were also analyzed in this study to assess the metabolism of CP-544439 in humans and ensure that selected animal species were exposed to all major metabolites formed in humans. Analysis suggested that CP-544439 was metabolized via all three pathways in humans consistent with rat and dog; however, the glucuronide conjugate M1 was the major circulating and excretory metabolite in humans. Preliminary in vitro phenotyping studies indicated that glucuronide formation is primarily catalyzed by UGT1A1, 1A3, and 1A9.
Asunto(s)
Ácidos Hidroxámicos/farmacocinética , Inhibidores de la Metaloproteinasa de la Matriz , Inhibidores de Proteasas/farmacocinética , Sulfonamidas/farmacocinética , Animales , Área Bajo la Curva , Proteínas Sanguíneas/metabolismo , Radioisótopos de Carbono , Cromatografía Líquida de Alta Presión , Perros , Femenino , Humanos , Ácidos Hidroxámicos/sangre , Ácidos Hidroxámicos/farmacología , Ácidos Hidroxámicos/orina , Masculino , Metaloproteinasa 13 de la Matriz/metabolismo , Microsomas Hepáticos/metabolismo , Inhibidores de Proteasas/sangre , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasas/orina , Ratas , Ratas Sprague-Dawley , Sulfonamidas/sangre , Sulfonamidas/farmacología , Sulfonamidas/orina , Distribución TisularRESUMEN
Disposition of traxoprodil ({1-[2-hydroxy-2-(4-hydroxy-phenyl)-1-methyl-ethyl]-4-phenyl-piperidin-4-ol}mesylate; TRX), a selective antagonist of the N-methyl-d-aspartate class of glutamate receptors, was investigated in rats and dogs after administration of a single i.v. bolus dose of [(14)C]TRX. Total mean recoveries of the radiocarbon were 92.5 and 88.2% from rats and dogs, respectively. Excretion of radioactivity was rapid and nearly complete within 48 h after dosing in both species. Whole-body autoradioluminography study suggested that TRX radioactivity was retained more by uveal tissues, kidney, and liver than by other tissues. TRX is extensively metabolized in rats and dogs since only 8 to 15% of the administered radioactivity was excreted as unchanged drug in the urine of these species. The metabolic pathways included aromatic hydroxylation at the phenylpiperidinol moiety, hydroxylation at the hydroxyphenyl ring, and O-glucuronidation. There were notable species-related qualitative and quantitative differences in the metabolism of TRX in rats and dogs. The hydroxylation at the 3-position of the phenol ring followed by methylation of the resulting catechol intermediate and subsequent conjugation were identified as the main metabolic pathways in dogs. In contrast, formation of the major metabolites in rats was due to oxidation at the 4'-position of the phenylpiperidinol moiety followed by further oxidation and phase II conjugation. TRX glucuronide conjugate was identified as the major circulating component in rats, whereas the glucuronide and sulfate conjugates of O-methyl catechol metabolite were the major metabolites in dog plasma. The site of conjugation of regioisomeric glucuronides was established from the differences in the collision-induced dissociation product ion spectra of their methylated products.
Asunto(s)
Piperidinas/metabolismo , Piperidinas/farmacocinética , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Animales , Bilis/metabolismo , Cromatografía Líquida de Alta Presión , Perros , Heces/química , Femenino , Ácido Glucurónico/metabolismo , Glucurónidos/análisis , Glucurónidos/biosíntesis , Inyecciones Intravenosas , Masculino , Microsomas Hepáticos/metabolismo , Estructura Molecular , Fármacos Neuroprotectores/administración & dosificación , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/farmacocinética , Piperidinas/sangre , Ratas , Ratas Long-Evans , Factores Sexuales , Espectrometría de Masas en Tándem , Distribución Tisular , Orina/químicaRESUMEN
CP-424391, 2-amino-N-[3aR-benzyl-2-methyl-3-oxo-2,3,3a,4,6,7-hexahydro-pyrazolo[4,3-c]pyridin-5-yl)-1R-benzyloxymethyl-2-oxoethyl]-isobutyramide, is an orally active growth hormone secretagogue currently being developed. In this study, we investigated the metabolic fate and disposition of radiolabeled CP-424391 in rats. Following 15 mg/kg single oral administration to Sprague-Dawley rats, 91% of the radiolabeled dose was recovered. Feces was the major route of excretion: 77% of the dose recovered in feces of the female rat and 84% in the male. Excretion in the urine was 15% in the female rat compared with 7% in the male. Both fecal and urinary metabolic profiles were consistent in both genders. The metabolic pathways of CP-424391 were oxidation at the benzyl group of the O-benzylserine moiety, N-demethylation of pyrazolidine, and/or O-debenzylation. In circulation, CP-424391 was absorbed within the first hour to an average apparent C(max) of 1.44 microg/ml. CP-424391 accounts for about 40% of radioactivity area under the plasma concentration-time curve and C(max) in circulation. The plasma terminal elimination half-life of CP-424391 was 2.4 h and for total radioactivity was 2.8 h. The radioactivity was widely distributed in all tissues except for the central nervous system. [(14)C]CP-424391 radioactivity was eliminated from most tissues by 9 h with the exception of liver, skin, and uvea. By 168 h, [(14)C]CP-424391 radioactivity remained localized only in the uvea.
Asunto(s)
Sustancias de Crecimiento/metabolismo , Piperidinas/metabolismo , Pirazoles/metabolismo , Administración Oral , Animales , Radioisótopos de Carbono/metabolismo , Radioisótopos de Carbono/orina , Heces/química , Femenino , Sustancias de Crecimiento/química , Sustancias de Crecimiento/orina , Masculino , Piperidinas/química , Piperidinas/orina , Pirazoles/química , Pirazoles/orina , Ratas , Ratas Long-Evans , Ratas Sprague-Dawley , Distribución Tisular/fisiologíaRESUMEN
Whole-body autoradioluminography (WBAL) has evolved as the preferred method for conducting tissue distribution studies that are required for regulatory filings of a new drug entity (DE) and for projecting tissue dosimetry in human mass balance studies. Four experiments were designed to assess WBAL utility using tritium as early as lead development in the drug discovery process. The objective of experiment 1 was to determine the minimum amount of tritium to administer to rats required for obtaining widespread distribution into most tissues at concentrations greater than quantification limits. Experiments 2, 3, and 4 were conducted to identify a tissue compartment responsible for observed triphasic pharmacokinetics, to characterize the distribution of a [3H]DE into brain tissue, and to compare tissue distribution patterns between two rat strains, respectively. The minimum amount of tritium necessary to investigate the tissue distribution of [3H]DE in rats was 865 microCi/kg. Results from experiments 2, 3, and 4 illustrated A) the identification of adipose as the tissue compartment responsible for an extended terminal elimination phase, B) sustained penetration of a DE into brain tissues for at least 24 h, and C) tissue distribution differences between two DEs of the same therapeutic class, respectively. These experiments exemplify the value of WBAL as a screening tool to assist with the selection of a drug candidate. WBAL utilization in drug discovery provides insightful data toward designing pharmacology and toxicology experiments. Substituting the use of tritium for carbon-14 is of crucial importance in drug discovery since [3H]DEs are more readily obtainable than [14C]DEs.