RESUMEN
AIMS: The aims of this work are (i) to characterize the absorption properties of orally administered formulations at different dose levels, and (ii) to evaluate the impact of entero-hepatic circulation on the time-course of amiodarone (AM) in rats in order to optimize the development of new oral (OR) formulations. METHODS: Intravenous (IV) formulation consisted on a solution of a commercial injectable of AM chlorhydrate. OR formulations included the IV commercial formulation (Trangorex®) (Solution I), an aqueous supramicellar solution of AM chlorhydrate with Polysorbate at 5% (Solution II) and a suspension from Trangorex® tablets (Tablet). Data from 96 male Wistar rats, including 985 AM observations, were analyzed using NONMEM v7.4. RESULTS: The population pharmacokinetic (PK) model assumes linear absorption processes, showing ka of AM from Solution II (Polysorbate 80, 5%) and Solution I increased by 2.5- and 1.62-fold compared to Tablet formulation. OR bioavailability of AM from Tablet, Solution I and Solution II was 37%, 40%, and 50%, respectively. The structural model of AM disposition was adapted from a previously population PK model and expanded by incorporating entero-hepatic reabsorption (EHR) processes, which estimated a 12.3% biliary excretion of AM and complete re-absorption from lumen. CONCLUSIONS: The current population PK model of AM demonstrated the absorption rate enhancement when AM is formulated with supramicellar concentrations of Polysorbate 80. The study design allowed to characterize the EHR of AM and its contribution in the overall AM disposition.
Asunto(s)
Amiodarona , Administración Oral , Animales , Disponibilidad Biológica , Estudios Cruzados , Circulación Enterohepática , Cinética , Masculino , Polisorbatos , Ratas , Ratas Wistar , ComprimidosRESUMEN
PURPOSE: The association between CVD risk factors and mortality is well established, however, current tools for addressing subgroups have focused on the overall burden of disease. The identification of risky combinations of characteristics may lead to a better understanding of physiologic pathways that underlie morbidity and mortality in older adults. METHODS: Participants included 5067 older adults from the Cardiovascular Health Study, followed for up to 6 years. Using latent class analysis (LCA), we created CV damage phenotypes based on probabilities of abnormal brain infarctions, major echocardiogram abnormalities, N-terminal probrain natriuretic peptide, troponin T, interleukin-6, c reactive-protein, galectin-3, cystatin C. We assigned class descriptions based on the probability of having an abnormality among risk factors, such that a healthy phenotype would have low probabilities in all risk factors. Participants were assigned to phenotypes based on the maximum probability of membership. We used Cox-proportional hazards regression to evaluate the association between the categorical CV damage phenotype and all-cause and CVD-mortality. RESULTS: The analysis yielded 5 CV damage phenotypes consistent with the following descriptions: healthy (59%), cardio-renal (11%), cardiac (15%), multisystem morbidity (6%), and inflammatory (9%). All four phenotypes were statistically associated with a greater risk of all-cause mortality when compared with the healthy phenotype. The multisystem morbidity phenotype had the greatest risk of all-cause death (HR: 4.02; 95% CI: 3.44, 4.70), and CVD-mortality (HR: 4.90, 95% CI: 3.95, 6.06). CONCLUSIONS: Five CV damage phenotypes emerged from CVD risk factor measures. CV damage across multiple systems confers a greater mortality risk compared to damage in any single domain.