RESUMEN
A potent synthetic α2-adrenergic agonist called PT-31, (3-(2-chloro-6-fluorobenzyl)-imidazolidine-2,4-dione), was recently detected as a potential drug to be used as an adjuvant drug to treat chronic pain. The excellent pharmacological property of PT-31 highlights the importance in elucidating its metabolism, which could provide valuable information about its metabolite profile for further pharmacokinetics studies and additionally to estimate the impact of its metabolites on the efficacy, safety and elimination of PT-31. In this work, the study of the in vitro metabolism of PT-31 was initially carried out by using a liquid chromatography coupled to ion trap multiple-stage mass spectrometer (LC-IT-MSn) and a hybrid triple quadrupole/linear ion trap mass spectrometer (LC-QTrap). The production of at least three unknown oxidative metabolites was observed. Structural identification of the unknown metabolites was carried out by combination of LC-MS experiments, including selected reaction monitoring (SRM) and multi-stage full scan experiments. Further analysis of 1H-NMR led to the structural confirmation of the major metabolite. The results indicated that PT-31 was metabolized by a hydroxylation reaction in the imidazolidine-2,4-dione ring in rat and human liver microsomes, producing the metabolite 3-(2-chloro-6-fluorobenzyl)-5-hydroxyimidazolidine-2,4-dione in rat liver microsomes. A carbon hydroxylation onto the benzyl ring, produced two other minor metabolites of the PT-31 in rat liver microsomes.
Asunto(s)
Agonistas de Receptores Adrenérgicos alfa 2/metabolismo , Analgésicos/metabolismo , Microsomas Hepáticos/metabolismo , Agonistas de Receptores Adrenérgicos alfa 2/farmacocinética , Agonistas de Receptores Adrenérgicos alfa 2/uso terapéutico , Analgésicos/farmacocinética , Analgésicos/uso terapéutico , Animales , Dolor Crónico/tratamiento farmacológico , Evaluación Preclínica de Medicamentos , Humanos , Imidazolidinas/metabolismo , Imidazolidinas/farmacocinética , Imidazolidinas/uso terapéutico , Espectroscopía de Resonancia Magnética , Oxidación-Reducción , Ratas , Espectrometría de Masas en TándemRESUMEN
Pre-clinical behavioral pharmacology studies supporting indications like analgesia typically consist of at least three different studies; dose-finding, duration of effect, and tolerance-development studies. Pharmacokinetic (PK) plasma samples are generally taken from a parallel group of animals to avoid disruption of the behavioral pharmacodynamic (PD) endpoint. Our objective was to investigate if pre-clinical behavioral pharmacology studies in rats could be performed effectively by combining three studies into a single experimental design and using sparse PK sampling in the same animals as for PD. A refined dosing strategy was applied for a muscarinic agonist, AZD6088, using the rat spinal nerve ligation heat hyperalgesia model. PD measurements were performed on day 1, 3, 5 and 8. Two PK samples per day were taken day 2 and 4. In a separate control group, PD measurements were performed on rats without PK sampling. Data was analyzed using a population approach in NONMEM. The animals produced a consistent and reproducible response irrespective of day of testing suggesting that blood sampling on alternate days did not interfere with the PD responses. A direct concentration-effect relationship with good precision was established and no tolerance development was observed. The new design combining three studies into one and eliminating a satellite PK group realized substantial savings compared to the old design; animal use was reduced by 58% and time required to generate results was reduced by 55%. The design described here delivers substantial savings in animal lives, time, and money whilst still delivering a good quality and precise description of the PKPD relationship.
Asunto(s)
Determinación de Punto Final/métodos , Hiperalgesia/tratamiento farmacológico , Imidazolidinas/farmacocinética , Modelos Biológicos , Agonistas Muscarínicos/farmacocinética , Piperidinas/farmacocinética , Animales , Ahorro de Costo , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/economía , Evaluación Preclínica de Medicamentos/métodos , Tolerancia a Medicamentos , Imidazolidinas/administración & dosificación , Imidazolidinas/farmacología , Masculino , Agonistas Muscarínicos/administración & dosificación , Agonistas Muscarínicos/farmacología , Dinámicas no Lineales , Piperidinas/administración & dosificación , Piperidinas/farmacología , Ratas , Ratas Sprague-Dawley , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
Elaboration of our previously disclosed spiropiperidine template led to the development of a series of novel CCR5 antagonists. Results of SAR exploration and preliminary lead characterization are described.
Asunto(s)
Antagonistas de los Receptores CCR5 , Imidazolidinas/síntesis química , Imidazolidinas/farmacología , Animales , Línea Celular , Evaluación Preclínica de Medicamentos , Humanos , Imidazolidinas/química , Imidazolidinas/farmacocinética , Ratas , Relación Estructura-ActividadRESUMEN
RO5068760, a substituted hydantoin, represents a new class of potent, highly selective, non-adenosine triphosphate (ATP)-competitive MEK1/2 inhibitors. The study aimed to determine the safety/tolerability, pharmacokinetics, and pharmacodynamics of single ascending doses of RO5068760 in human healthy volunteers. All participants received a single dose followed by 48 hours of pharmacokinetics, pharmacodynamics, and safety/tolerability assessments. The pharmacodynamics were measured by changes in ERK phosphorylation (pERK) in peripheral blood mononuclear cells, ex vivo stimulated by phorbol 12-myristate 13-acetate (PMA). Forty-eight participants received 6 doses (50, 100, 200, 400, 600, 800 mg). RO5068760 was well tolerated up to 800 mg. There were no clinically significant safety findings, including laboratory, electrocardiogram, ophthalmological assessment, and fecal occult blood tests. Of the total 13 adverse events (n = 12), 11 were mild, 2 were moderate, and none were severe, and only 5 were considered by the investigator as possibly related to treatment. RO5068760 was absorbed with a t(max), of 2 hours. Disposition appeared to be biphasic with a terminal elimination t(1/2) of 5 to 9 hours. The variability was moderate to high, ranging from 38% to 62% for C(max) and 41% to 69% AUC. Within the dose range tested, pERK inhibition was relatively modest with a mean maximal pERK suppression of 55%.