Designing an effective dissolution test for bilayer tablets tailored for optimal melatonin release in sleep disorder management.

This project aims to investigate the release performance of bilayer tablet (BL-Tablet) designed with both fast and slow-release technology, targeting sleep disorders. The tablet incorporates Melatonin, extracts of Eschscholzia californica and Melissa officinalis. In order to validate the effectiveness of the extended-release profile, an advanced dissolution test was herein proposed. This new method utilizes biorelevant intestinal fluid media and incorporates a stomach-to-intestine fluid changing (SIFC) system. To demonstrate the advantages of employing this method for assessing the controlled release profile of active ingredients, the dissolution results were compared with those obtained using the conventional EU Pharmacopoeia approach. Furthermore, the comparative analysis was extended to include a monolayer tablet version (ML-Tablet) lacking the slow-release technology. Technological characterization and bioaccessibility studies, including intestinal permeability test, were conducted as well to assess the pharmacological performance and bioavailability of active ingredients. The dissolution data recovered revealed that the two dissolution methods did not exhibit any significant differences in the release of ML-Tablet's. However, the dissolution profile of the BL-Tablet exhibited notable differences between the two methods particularly when assessing the behavior of the slow-release layer. In this scenario, both methods initially exhibited a similar release pattern within the first approximately 0.5 h, driven by the fast-release layer of the tablet. Following this, distinct gradual and sustained releases were observed, spanning 2.5 h for the EU Pharmacopoeia method and 8 h for the new SIFC-biorelevant dissolution method, respectively. Overall, the novel method demonstrated a substantial improvement compared to conventional EU Pharmacopoeia test in evaluating the performance of a controlled slow-release technology. Remarkably, the prolonged release technology did not have an adverse impact on melatonin intestinal absorption, and, consequently, maintaining its potential bioavailability of around 78%. Concluding, this research provides valuable insights into how the innovative dissolution test can assist formulators in developing controlled release formulations.

Acyl-Carnitines Exert Positive Effects on Mitochondrial Activity under Oxidative Stress in Mouse Oocytes: A Potential Mechanism Underlying Carnitine Efficacy on PCOS.

Carnitines play a key physiological role in oocyte metabolism and redox homeostasis. In clinical and animal studies, carnitine administration alleviated metabolic and reproductive dysfunction associated with polycystic ovarian syndrome (PCOS). Oxidative stress (OS) at systemic, intraovarian, and intrafollicular levels is one of the main factors involved in the pathogenesis of PCOS. We investigated the ability of different acyl-carnitines to act at the oocyte level by counteracting the effects of OS on carnitine shuttle system and mitochondrial activity in mouse oocytes. Germinal vesicle (GV) oocytes were exposed to hydrogen peroxide and propionyl-l-carnitine (PLC) alone or in association with l-carnitine (LC) and acetyl-l-carnitine (ALC) under different conditions. Expression of carnitine palmitoyltransferase-1 (Cpt1) was monitored by RT-PCR. In in vitro matured oocytes, metaphase II (MII) apparatus was assessed by immunofluorescence. Oocyte mitochondrial respiration was evaluated by Seahorse Cell Mito Stress Test. We found that Cpt1a and Cpt1c isoforms increased under prooxidant conditions. PLC alone significantly improved meiosis completion and oocyte quality with a synergistic effect when combined with LC + ALC. Acyl-carnitines prevented Cpt1c increased expression, modifications of oocyte respiration, and ATP production observed upon OS. Specific effects of PLC on spare respiratory capacity were observed. Therefore, carnitine supplementation modulated the intramitochondrial transfer of fatty acids with positive effects on mitochondrial activity under OS. This knowledge contributes to defining molecular mechanism underlying carnitine efficacy on PCOS.

Coumarin as attractive casein kinase 2 (CK2) inhibitor scaffold: an integrate approach to elucidate the putative binding motif and explain structure-activity relationships.

Casein kinase 2 (CK2) is an ubiquitous, essential, and highly pleiotropic protein kinase whose abnormally high constitutive activity is suspected to underlie its pathogenic potential in neoplasia and other diseases. Recently, using different virtual screening approaches, we have identified several novel CK2 inhibitors. In particular, we have discovered that coumarin moiety can be considered an attractive CK2 inhibitor scaffold. In the present work, we have synthetized and tested a small library of coumarins (more than 60), rationalizing the observed structure-activity relationship. Moreover, the most promising inhibitor, 3,8-dibromo-7-hydroxy-4-methylchromen-2-one (DBC), has been also crystallized in complex with CK2, and the experimental binding mode has been used to derive a linear interaction energy (LIE) model.