Quercetin (QUE) is a flavonol that has recently received great attention from the research community due to its important pharmacological properties. However, QUE’s low solubility and extended first-pass metabolism limit its oral administration. This review aims to present the potential of various nanoformulations in the development of QUE dosage forms for bioavailability enhancement. Advanced drug delivery nanosystems can be used for more efficient encapsulation, targeting, and controlled release of QUE. An overview of the primary nanosystem categories, formulation processes, and characterization techniques are described. In particular, lipid-based nanocarriers, such as liposomes, nanostructured-lipid carries, and solid-lipid nanoparticles, are widely used to improve QUE’s oral absorption and targeting, increase its antioxidant activity, and ensure sustained release. Moreover, polymer-based nanocarriers exhibit unique properties for the improvement of the Absorption, Distribution, Metabolism, Excretion, and Toxicology (ADME(T)) profile. Namely, micelles and hydrogels composed of natural or synthetic polymers have been applied in QUE formulations. Furthermore, cyclodextrin, niosomes, and nanoemulsions are proposed as formulation alternatives for administration via different routes. This comprehensive review provides insight into the role of advanced drug delivery nanosystems for the formulation and delivery of QUE.

Ropinirole is a non-ergolinic dopamine agonist used to manage Parkinson’s disease and it is characterized by poor oral bioavailability. This study aimed to design and develop advanced drug delivery systems composed of poloxamer 407, a non-ionic surfactant (Tween 80), and cyclodextrins (methyl-β-CD or hydroxy-propyl-β-CD) for possible brain targeting of ropinirole after nasal administration for the treatment of Parkinson’s disease. The hybrid systems were formed by the thin-film hydration method, followed by an extensive physicochemical and morphological characterization. The in vitro cytotoxicity of the systems on HEK293 cell lines was also tested. In vitro release and ex vivo mucosal permeation of ropinirole were assessed using Franz cells at 34 °C and with phosphate buffer solution at pH 5.6 in the donor compartment, simulating the conditions of the nasal cavity. The results indicated that the diffusion-controlled drug release exhibited a progressive increase throughout the experiment, while a proof-of-concept experiment on ex vivo permeation through rabbit nasal mucosa revealed a better performance of the prepared hybrid systems in comparison to ropinirole solution. The encouraging results in drug release and mucosal permeation indicate that these hybrid systems can serve as attractive platforms for effective and targeted nose-to-brain delivery of ropinirole with a possible application in Parkinson’s disease. Further ex vivo and in vivo studies to support the results of the present work are ongoing.

Hybrid PEO-b-PCL/Tween 80/cyclodextrin systems: physicochemical and morphological characterization, and in vitro release studies.

According to the latest epidemiological data, breast cancer has recently been the most frequently diagnosed malignancy. To date, a body of evidence has established the involvement of multiple - and frequently interrelated - genetic and environmental factors in the pathogenesis of the disease. Emerging research on cancer prevention has highlighted the deterrence potential of interventions targeting environmental risk factors, particularly diet. In this aspect, the current review reveals the latest scientific results regarding epigallocatechin-3-gallate (EGCG) - a catechin most commonly found in green tea, as a potential chemopreventive dietary agent against breast cancer. in vitro studies on EGCG have demonstrated its effect on cell cycle progression and its potential to suppress several intracellular signaling pathways involved in breast cancer pathogenesis. In addition, EGCG possesses specific apoptosis-inducing characteristics that seem to enhance its role as a regulator of cell survival. Preclinical data seem to support using EGCG as an effective adjunct to EGFR-targeting treatments. The authors’ appraisal of the literature suggests that although preclinical evidence has documented the anticarcinogenic features of EGCG, limited large-scale epidemiological studies are investigating the consumption of EGCG - containing nutrients in the prevention and management of breast cancer risk. This literature review aims to liaise between preclinical and epidemiological research, surveying the existing evidence and unraveling relevant knowledge gaps.

Nasal administration has emerged as an effective alternative for drug delivery to central nervous system (CNS), particularly in neurodegenerative diseases. Ropinirole hydrochloride (RH) is used as a monotherapy or as an adjunctive combination with levodopa for the management of Parkinson's disease. However, RH undergoes extensive first-pass metabolism, thereby limiting the amount of drug reaching the CNS. The purpose of the present study was the determination of the pharmacokinetic parameters of RH when administered intranasally as colloidal dispersion [(P407/Tw80/HPβCD)/RH 10:5] and as a powder [(P407/Tw80/HPβCD)/RH 10:5 blended with mannitol/lecithin microparticles (25:75)] for brain targeting. In particular, the pharmacokinetic study was carried out in comparison with oral (per os) and IN administration of pure RH solution in C57BL/6J mice. The brain and serum distribution pharmacokinetics of the drug were studied applying the sparse sampling non-compartmental analysis (NCA). The pharmacokinetic profiles after intranasal and per os administration revealed the efficiency of intranasal administration in rapidly and effectively delivering RH, both to the CNS and bloodstream. The pre-eminence of the nasal formulations is witnessed by higher serum AUC and C_max values after intranasal administration of formulations compared to the per os administration of RH solution. Notably, the intranasal administration of the RH powder resulted in the highest systemic bioavailability (F_rel(Serum) = 1497 %) and brain exposure (F_rel(Brain) = 541 %), suggesting a promising role for nasal delivery in targeting the CNS.