Identification of Transporter Polymorphisms Influencing Metformin Pharmacokinetics in Healthy Volunteers.

For patients with type 2 diabetes, metformin is the most often recommended drug. However, there are substantial individual differences in the pharmacological response to metformin. To investigate the effect of transporter polymorphisms on metformin pharmacokinetics in an environment free of confounding variables, we conducted our study on healthy participants. This is the first investigation to consider demographic characteristics alongside all transporters involved in metformin distribution. Pharmacokinetic parameters of metformin were found to be affected by age, sex, ethnicity, and several polymorphisms. Age and SLC22A4 and SLC47A2 polymorphisms affected the area under the concentration-time curve (AUC). However, after adjusting for dose-to-weight ratio (dW), sex, age, and ethnicity, along with SLC22A3 and SLC22A4, influenced AUC. The maximum concentration was affected by age and SLC22A1, but after adjusting for dW, it was affected by sex, age, ethnicity, ABCG2, and SLC22A4. The time to reach the maximum concentration was influenced by sex, like half-life, which was also affected by SLC22A3. The volume of distribution and clearance was affected by sex, age, ethnicity and SLC22A3. Alternatively, the pharmacokinetics of metformin was unaffected by polymorphisms in ABCB1, SLC2A2, SLC22A2, or SLC47A1. Therefore, our study demonstrates that a multifactorial approach to all patient characteristics is necessary for better individualization.

Bioavailability of Oniria®, a Melatonin Prolonged-Release Formulation, Versus Immediate-Release Melatonin in Healthy Volunteers.

BACKGROUND: Melatonin is an endogenous substance which plays a key role in sleep induction by reducing sleep onset latency; it has been approved by the European Food Safety Authority as a food supplement for exogenous administration. Oniria® is a food supplement formulated as 1.98 mg of prolonged-release melatonin tablets; it displays a dual dissolution profile in vitro. OBJECTIVES: The main objective of the present study was to evaluate the relative oral bioavailability of Oniria®, in comparison with immediate-release tablets (IRT) with a similar melatonin content as a reference. We also attempted to characterize the circadian rhythm of endogenous melatonin. METHODS: We performed an open-label, cross-over, randomized, phase I clinical study with two sequences and three periods involving 14 healthy volunteers. We characterized the endogenous melatonin circadian profile (period 1) and pharmacokinetics (PK) of both Oniria® and the reference melatonin (periods 2 and 3). RESULTS: Two phases were clearly differentiated in the PK profile of Oniria®. An initial one, from dosing up to 2 h, and a delayed one from 2 to 11 h post-administration. During the initial phase, both melatonin formulations were equivalent, with a Cmax value close to 4000 pg/mL. However, in the delayed phase, Oniria® showed significantly higher melatonin concentrations than the IRT (three times higher at 4-6 h post-administration). Moreover, Oniria® exhibited concentrations above the endogenous melatonin peak of 80 pg/mL for up to 2.5 h versus the reference formulation, potentially suggesting an effect of Oniria®, not only in the induction of sleep, but also in the maintenance. CONCLUSION: Oniria® could be a highly promising food supplement, not only for sleep induction but also for the maintenance of sleep.

First-in-human phase I clinical trial of a TLR4-binding DNA aptamer, ApTOLL: Safety and pharmacokinetics in healthy volunteers.

ApTOLL is an aptamer that antagonizes Toll-like receptor 4 and improves functional outcomes in models of ischemic stroke and myocardial infarction. The aim of this study was to characterize the safety and pharmacokinetics of ApTOLL in healthy volunteers. A first-in-human dose-ascending, randomized, placebo-controlled phase I clinical trial to assess safety and pharmacokinetics of ApTOLL (30-min infusion intravenously) was performed in 46 healthy adult male volunteers. The study was divided into two parts: part A included seven single ascending dose levels, and part B had one multiple dose cohort. Safety and pharmacokinetic parameters were evaluated. No serious adverse events or biochemistry alterations were detected at any dose nor at any administration pattern studied. Maximum concentration was detected at the end of the infusion and mean half-life was 9.3 h. Interestingly, exposure increased in the first four levels receiving doses from 0.7 mg to 14 mg (AUC of 2,441.26 h∗ng/mL to 23,371.11 h∗ng/mL) but remained stable thereafter (mean of 23,184.61 h∗ng/mL after 70 mg). Consequently, the multiple dose study did not show any accumulation of ApTOLL. These results show an excellent safety and adequate pharmacokinetic profile that, together with the efficacy demonstrated in nonclinical studies, provide the basis to start clinical trials in patients.