Search Results (223)

Quercetin (Que) is widely recognized for its antioxidant and neuroprotective properties; however, its clinical potential remains limited due to poor solubility and low oral bioavailability. Nasal powders have emerged as a promising strategy to overcome these limitations, taking advantage of nose-to-brain delivery, offering a direct, non-invasive route to the central nervous system while bypassing first-pass metabolism. This study aims to extend previous work by systematically investigating the impact of different preparation methods (spray drying vs. lyophilization) and the incorporation of hydroxypropyl methylcellulose (HPMC) and mannitol/lecithin microparticles (MLMPs) on the physicochemical characteristics, structural properties, and in vitro diffusion behavior of HPβCD-based nasal powder formulations of Que. Thermal behavior and stability were analyzed using TGA, while morphology and particle distribution were assessed via Scanning Electron Microscopy. In vitro diffusion studies using Franz cells and regenerated cellulose membranes were conducted under simulated nasal conditions. Among all tested formulations, the spray-dried HPβCD/Que powder (F4) showed the highest permeation (0.11 ± 0.01 mg/cm² at 120 min). The inclusion of HPMC improved thermal stability but reduced Que diffusion, likely due to increased viscosity and matrix formation. Blending with MLMPs enhanced powder flow and dose placement, although it modestly reduced diffusion efficiency. Overall, this study highlights the potential of HPβCD-based spray-dried powders for nasal Que delivery and demonstrates how HPMC and MLMPs can be strategically employed to tailor performance characteristics. Full article

Background: Silymarin, a flavonoid complex, and the main bioactive component of milk thistle (Silybum marianum), is known for its hepatoprotective properties but suffers from poor bioavailability due to its low solubility and extensive first-pass metabolism. Method: This study aimed to evaluate the pharmacokinetics and tolerability of a novel micellar milk thistle formulation designed to enhance silymarin absorption, compared to an unformulated/standard milk thistle product, in a small-scale human bioavailability trial. In a randomized, double-blinded, crossover study, 16 healthy participants received a single dose of either the micellar formulation (LipoMicel Milk Thistle; LMM) or the standard formulation (STD) at a total daily dose of 130 mg silymarin. Blood concentrations were measured over 24 h, and key pharmacokinetic parameters—maximum plasma concentration (C_max), time to reach maximum concentration (T_max), and area under the curve (AUC)—were calculated. Tolerability and safety were assessed through adverse event monitoring during the study period. Results: Results demonstrated a significant increase in bioavailability with the micellar formulation, with 18.9-fold higher C_max (95% CI: 1.9–30.7 ng/mL vs. 74.4–288.3 ng/mL; p = 0.007) and 11.4-fold higher AUC_0–24 (95% CI: 7.40–113.5 ng·h/mL vs. 178–612.5 ng·h/mL; p = 0.015). T_max was 0.5 (95% CI: 0.5–4.0) hours for the micellar formulation versus 2.5 (95% CI: 0.5–8.0) hours for the standard product (p = 0.015) indicating faster absorption of LMM. The standard formulation exhibited a significantly longer mean residence time compared to the LMM formulation (95% CI: 4.4–7.5 h vs. 2.8–4.2 h; p = 0.015). Conclusions: No adverse events or significant safety concerns were observed in either group. Compared to the standard, the micellar formulation showed superior pharmacokinetic outcomes, suggesting it may enhance silymarin’s clinical efficacy in liver health. Full article

Background/Objectives: Early diagnosis and oral or, in severe cases, intravenous antibiotics are usually effective for Lyme disease, but some patients have persistent symptoms unresponsive to standards of care, requiring alternative therapies. Disulfiram (DIS), a drug for alcoholism, is under investigation as a potential adjunctive treatment, but its low bioavailability, rapid metabolism, and safety concerns urge the development of improved formulations for clinical translation. Methods: Screening dissolution and permeation studies were investigated for vehicle and excipient selection, following the pharmacopeia perspectives to develop and optimize the low-dose DIS rectal suppository intended for application in post-treatment Lyme disease syndrome (PTLDS). Further characterizations were carried out by differential scanning calorimetry, X-ray diffraction, and infrared spectroscopy. Results: Cyclodextrin (CD) encapsulation was investigated to improve the aqueous solubility of the hydrophobic drug. The dissolution of DIS from fatty base suppository was very slow; it was remarkably improved by the molecular encapsulation of the drug with CDs. The dissolution of DIS from a water-soluble base was more favorable, but incomplete. In the polyethylene glycol (PEG) based suppositories, the addition of CDs already in a physical mixture ensured the dissolution of the drug. The presented drug delivery system relates to a novel preparation for rectal administration comprising a low-dose disulfiram with improved solubility and permeability by the PEG and hydroxypropyl-β-cyclodextrin (HPBCD) synergistic matrix. Conclusions: The rectal dosage form containing the drug and CD in the physical mixture is advantageous, avoiding the hepatic first-pass effect, minimizing dose-limiting toxicity, simplifying production, and fasting the availability of the repositioned drug. Full article

Background: Olanzapine (Ola) is a second-generation antipsychotic with clinical utility limited by poor brain bioavailability due to blood–brain barrier restriction, hepatic first-pass metabolism, and systemic side effects. This study aimed to develop and optimize a novel intranasal polymersome-based nanocarrier (Poly_Ola) to enhance brain targeting, therapeutic efficacy, and safety of Ola. Methods: Poly_Ola was prepared using poloxamer 401 and optimized through a Box–Behnken Design to minimize particle size and maximize entrapment (EE%) and loading efficiency (LE%). The formulation was characterized by size, morphology, drug release, and serum stability. In vivo studies in adult male Sprague-Dawley rats assessed pharmacokinetics (plasma and brain concentrations), pharmacodynamic efficacy in a ketamine-induced schizophrenia model, and systemic safety markers including metabolic, hepatic, and testicular oxidative stress indicators. Results: Optimized Poly_Ola exhibited a particle size of 78.3 ± 4.5 nm, high EE% (91.36 ± 3.55%), and sustained in vitro drug release. It remained stable in serum for 24 h. Intranasal administration significantly improved brain delivery of Ola, achieving a 2.7-fold increase in C_max and a 5.7-fold increase in AUC compared to oral dosing. The brain T_max was 15 min, with high drug-targeting efficiency (DTE% = 365.38%), confirming efficient nose-to-brain transport. Poly_Ola-treated rats showed superior antipsychotic performance, reduced extrapyramidal symptoms, and improved systemic safety evidenced by mitigated weight gain, glycemic control, normalized liver enzymes, and reduced oxidative stress. Conclusions: Poly_Ola offers a safe and effective intranasal delivery platform for Ola, enabling targeted brain delivery and improved management of schizophrenia with reduced peripheral toxicity. Full article

Oleocanthal (OC), a secoiridoid phenolic compound exclusive to extra virgin olive oil (EVOO), has emerged as a promising nutraceutical with multifaceted anti-cancer properties. Despite its well-characterized anti-inflammatory and antioxidant effects, the mechanistic breadth and translational potential of OC in oncology remain underexplored and fragmented across the literature. This comprehensive review synthesizes and critically analyzes recent advances in the molecular, pharmacological, and translational landscape of OC’s anti-cancer activities, providing an integrative framework to bridge preclinical evidence with future clinical application. We delineate the pleiotropic mechanisms by which OC modulates cancer hallmarks, including lysosomal membrane permeabilization (LMP)-mediated apoptosis, the inhibition of key oncogenic signaling pathways (c-MET/STAT3, PAR-2/TNF-α, COX-2/mPGES-1), the suppression of epithelial-to-mesenchymal transition (EMT), angiogenesis, and metabolic reprogramming. Furthermore, this review uniquely highlights the emerging role of OC in modulating drug resistance mechanisms by downregulating efflux transporters and sensitizing tumors to chemotherapy, targeted therapies, and immunotherapies. We also examine OC’s bidirectional interaction with gut microbiota, underscoring its systemic immunometabolic effects. A major unmet need addressed by this review is the lack of consolidated knowledge regarding OC’s pharmacokinetic limitations and drug–drug interaction potential in the context of polypharmacy in oncology. We provide an in-depth analysis of OC’s poor bioavailability, extensive first-pass metabolism, and pharmacogenomic interactions, and systematically compile preclinical evidence on advanced delivery platforms—including nanocarriers, microneedle systems, and peptide–drug conjugates—designed to overcome these barriers. By critically evaluating the mechanistic, pharmacological, and translational dimensions of OC, this review advances the field beyond isolated mechanistic studies and offers a strategic blueprint for its integration into precision oncology. It also identifies key research gaps and outlines the future directions necessary to transition OC from a nutraceutical of dietary interest to a viable adjunctive therapeutic agent in cancer treatment. Full article

The rapid pace of modern life has contributed to a significant decline in sleep quality, which has become an urgent global public health issue. Melatonin, an endogenous hormone that regulates circadian rhythms, is vital in maintaining normal sleep cycles. While oral melatonin supplementation is widely used, transdermal delivery systems present advantages that include the avoidance of first-pass metabolism effects and enhanced bioavailability. In this study, a novel melatonin transdermal delivery system was successfully developed using a thermosensitive poly(N-vinylcaprolactam) [p(NVCL)]-based carrier. The p(NVCL) polymer was synthesized through free radical polymerization and characterized for its structural properties and phase transition temperature, in alignment with skin surface conditions. Orthogonal optimization experiments identified 3% azone, 3% menthol, and 4% borneol as the optimal enhancer combination for enhanced transdermal absorption. The formulation demonstrated exceptional melatonin loading characteristics with high encapsulation efficiency and stable physicochemical properties, including an appropriate pH and optimal moisture content. Comprehensive in vivo evaluation using normal mouse models revealed significant sleep quality improvements, specifically a shortened sleep latency and extended non-rapid eye movement sleep duration, with elevated serum melatonin and serotonin levels. Safety assessments including histopathological examination, biochemical analysis, and 28-day continuous administration studies confirmed excellent biocompatibility with no adverse reactions or systemic toxicity. Near-infrared fluorescence imaging provided direct evidence of enhanced transdermal absorption and superior biodistribution compared to oral administration. These findings indicate that the p(NVCL)-based melatonin transdermal gel system offers a safe, effective and convenient non-prescription option for sleep regulation, with promising potential for clinical translation as a consumer sleep aid. Full article

Biochemical alterations linked to metabolic syndrome (MetS), type 2 diabetes (T2DM), and metabolic dysfunction-associated steatotic liver disease (MASLD) may be brought on by the Western diet. Based on research conducted over the past decade, fructose is one of the main culprits. Over 80% of ingested fructose is metabolized by the liver at first pass, where it stimulates de novo lipogenesis (DNL) to drive hepatic triglyceride (TG) synthesis, which contributes to MASLD, hepatic insulin resistance (IR), and dyslipidemia. Fructose reduction produces quick and significant amelioration in these metabolic disturbances. We hereby propose potential overarching processes that can link these pathways to signaling disruption by the critical metabolic sensor AMP-activated protein kinase (AMPK). We proffer that when large amounts of fructose and glucose enter the liver, triose fluxes may be sufficient to produce transient increases in methylglyoxal (MG), allowing steady-state concentrations between its production and catabolism by glyoxalases to be high enough to modify AMPK-sensitive functional amino acid residues. These reactions would transiently interfere with AMPK activation by both AMP and aldolase. Such a sequence of events would boost the well-documented lipogenic impact of fructose. Given that MG adducts are irreversible, modified AMPK molecules would be less effective in metabolite sensing until they were replaced by synthesis. If proven, this mechanism provides another avenue of possibilities to tackle the problem of fructose in our diet. We additionally discuss potential multimodal treatments and future research avenues for this apparent hepatic AMPK malfunction. Full article

Transdermal drug delivery systems (TDDSs) provide a non-invasive alternative to oral and parenteral routes, delivering drugs into the bloodstream while avoiding gastrointestinal degradation and first-pass metabolism. Despite benefits like enhanced bioavailability and patient compliance, the stratum corneum limits drug permeation. Ethosomes overcome the stratum corneum barrier with superior flexibility and permeability compared to liposomes. Ethanol disrupts the skin’s lipid bilayer, enabling deep penetration and efficient drug delivery. Ethosomes offer high entrapment efficiency and stability, delivering both hydrophilic and lipophilic drugs. However, challenges like stability optimization and clinical translation persist. This review examines the structural components, preparation methods, and therapeutic applications of ethosomes in metabolic and chronic diseases, including diabetes, cardiovascular diseases, neurodegenerative disorders, arthritis, and cancers. Moreover, it highlights the potential of ethosomes to revolutionize TDDSs for managing chronic and metabolic diseases, providing a foundation for further research and clinical development. Full article

Inherited metabolic disorders (IMDs) are genetic disorders that occur in as many as 1:2500 births worldwide. Nevertheless, they are quite rare individually and even more rare is the co-occurrence of two IMDs in one individual. To better understand the metabolic cross-talk between glycosylation changes and deficient energy metabolism, and its potential effect on outcomes, we evaluated patient fibroblasts with likely pathogenic variants in PGM1 and pathogenic variants in NDUFA13 derived from a patient who passed away at 16 years of age. The patient presented with characteristic of PGM1-CDG including bifid uvula, muscle involvement, abnormal glycosylation in blood, and elevated liver transaminases. In addition, hearing loss, seizures, elevated plasma and CSF lactate and a Leigh-like MRI brain pattern were present, which are commonly associated with Leigh syndrome. PGM1-CDG has been reported in about 70 individuals, while NDUFA13 deficiency has so far only been reported in 13 patients. As abundant energy is essential for glycosylation, and both PGM1 and NDUFA13 are linked to energy metabolism, we sought to better understand the underlying biochemical cause of the patient’s clinical presentation. To do so, we performed extensive investigations including tracer metabolomics, lipidomics and enzymatic studies on the patient’s fibroblasts. We found a profound depletion of UDP-hexoses, consistent with PGM1-CDG. Complex I enzyme activity and mitochondrial function were also impaired, corroborating complex I deficiency and Leigh syndrome. Further, lipidomics analysis showed similarities with both PGM1-CDG and OXPHOS-deficient patients. Based on our results, the patient was diagnosed with both PGM1-CDG and Leigh syndrome. In summary, we present the first case of combined CDG and Leigh syndrome, caused by (likely) pathogenic variants in PGM1 and NDUFA13, and underline the importance of considering the synergistic effects of multiple disease-causing variants in patients with complex clinical presentation, leading to the patient’s early demise. Full article

Background: Candesartan cilexetil, a Biopharmaceutics Classification System (BCS) II prodrug, demonstrates compromised bioavailability attributable to its limited aqueous solubility coupled with P-glycoprotein (P-gp)-mediated efflux and hepatic first-pass metabolism, thereby introducing complexities in generic drug bioequivalence assessments. With the rapid advancement of computational technologies, the integration of biorelevant dissolution methodologies with physiologically based pharmacokinetic (PBPK) modeling is emerging as a transformative paradigm in advancing bioequivalence evaluation strategies for generic drug products. This study presents a GastroPlus^®-driven framework integrating in vivo predictive dissolution (IPD) and virtual bioequivalence (VBE) to evaluate the quality consistency of generic candesartan cilexetil tablets. Methods: By developing an oral PBPK model in GastroPlus^®, we established an IPD method using a phosphate-buffer-based flow-through cell dissolution apparatus. In vitro dissolution profiles of generic tablets from four manufacturers were measured and incorporated into the model to perform VBE simulations. Results: The results demonstrated that only the product from Company A achieved virtual bioequivalence with the reference product, aligning with real-world quality consistency assessments. Conclusions: The proposed framework exhibited robust predictive capability, bridging in vitro dissolution data to in vivo bioequivalence outcomes, thereby offering a cost-effective and efficient strategy for formulation optimization and preclinical bioequivalence evaluation of generic drugs. Full article

Cannabidiol (CBD) has gained popularity in veterinary medicine for its potential to alleviate stress, pain, and inflammation in dogs. However, its oral administration is limited by hydrophobicity, variable absorption, and extensive first-pass metabolism, which requires optimized delivery methods to enhance efficacy. This study investigated the effects of daily oral supplementation of CBD oil and CBD gel (each at 4 mg/kg), compared to a placebo, over 14 days in shelter dogs subjected to solitary confinement-induced stress. Both CBD formulations appeared safe under the study conditions, with no adverse effects on hematological and biochemical parameters. Post-stress cortisol levels were significantly lower in CBD-treated groups compared to controls, with CBD-infused gel showing a pattern toward greater attenuation. Multivariate analysis revealed distinct blood profile shifts in CBD-treated dogs, with PCA loadings indicating associations between CBD supplementation and lymphocyte percentages and IgG levels. These findings support gel-based CBD as a promising strategy for stress modulation in dogs. Further studies should explore its pharmacokinetics and long-term immune effects to optimize veterinary applications. Full article

The aim of this study was to investigate the influence of solid dispersion (SD) formulation factors on improvement of the bioavailability and pharmacokinetic profile of clopidogrel after peroral administration using an in vitro–in silico approach. A clopidogrel-specific, physiologically based biopharmaceutical model (PBBM) was developed and validated to predict absorption and distribution of clopidogrel after peroral administration of the tested formulations. Clopidogrel solid dispersions were prepared using two polymers (poloxamer 407 and copovidone) and a drug-to-polymer ratio of 1:5 and 1:9. The results of the in vitro dissolution test under pH–media change conditions showed that the type and ratio of polymers notably influenced the release of clopidogrel from the SDs. It can be observed that an increase in the polymer content in the SDs leads to a decrease in the release of clopidogrel from the SDs. The predictive power of the constructed clopidogrel-specific PBBM was demonstrated by comparing the simulation results with pharmacokinetic data from the literature. The in vitro dissolution data were used as inputs for the PBBM to predict the pharmacokinetic profiles of clopidogrel after the peroral administration of SDs. SDs with copovidone (1:5) and poloxamer (1:9) showed the potential to achieve the highest drug absorption and bioavailability, with an improvement of over 100% compared to an immediate-release (IR) tablet. The sample with poloxamer (1:9) may have the potential to reduce inter-individual variability in clopidogrel pharmacokinetics due to absorption in the cecum and colon and associated lower first-pass metabolism in the liver. This suggests that distal intestine may be the targeted delivery site for clopidogrel, leading to improved absorption and bioavailability of the drug. This study has shown that an in vitro–in silico approach could be a useful tool for the development and optimization of clopidogrel formulations, helping in decision making regarding the composition of the formulation to achieve the desired pharmacokinetic profile. Full article

Background: Captopril (CAP), an angiotensin-converting enzyme inhibitor (ACEI), is widely prescribed for managing hypertension, heart failure, and related conditions. When administered orally, CAP undergoes hepatic metabolism, resulting in a bioavailability of 60–75%. However, to bypass the first-pass metabolism and other limitations of the oral route, mucoadhesive buccal films have gained attention as a promising alternative with several advantages. The aim of this work was the formulation and optimization of chitosan-ascorbate mucoadhesive films for buccal delivery of CAP for the management of a hypertension crisis (10 mg and 20 mg) by employing quality by design (QbD) principles and the design of experiment (DoE) approach. Materials and methods: In the present work, chitosan (CHI) was selected as a film-forming agent due to its permeability-enhancing properties, which could be further improved through salification with ascorbic acid (AA). The polymer films were prepared by the solvent casting method. Results: The optimized CAP-loaded formula showed appropriate in vitro mucoadhesion force (>15 N) and breaking hardness (>14 N). The different CAP-containing films had a high drug content (>95%) with homogeneous drug distribution, thus complying with the requirements of Pharmacopeia. FT-IR and RAMAN spectroscopy analyses demonstrated successful incorporation of the drug, and interaction was observed between the excipients of the films, especially in the form of hydrogen bonds. The dissolution test showed immediate release of the API with a similar release pattern from both concentrations of CAP-loaded films. Conclusions: The properties of the prepared films met the predetermined critical quality attribute requirements. The optimized formula of CHI 1.4%, AA 2.5%, and glycerol 0.3% appears to be a promising buccal drug delivery system for CAP. Full article

Cancer is considered as the second leading cause of death worldwide. Chemotherapy, radiotherapy, immunotherapy, and targeted drug delivery are the main treatment options for treating cancers. Chemotherapy drugs are either available for oral or parenteral use. Oral chemotherapy, also known as chemotherapy at home, is more likely to improve patient compliance and convenience. Oral anti-cancer drugs have bioavailability issues associated with lower aqueous solubility, first-pass metabolism, poor intestinal permeability and drug absorption, and degradation of the drug throughout its journey in the gastrointestinal tract. A highly developed carrier system known as lipid polymer hybrid nanoparticles (LPHNs) has been introduced. These nanocarriers enhance drug stability, solubility, and absorption, and reduce first-pass metabolism. Consequently, this will have a positive impact on oral bioavailability enhancement. This article provides an in-depth analysis of LPHNs as a novel drug delivery system for anti-cancer agents. It discusses an overview of the limited bioavailability of anti-cancer drugs, their reasons and consequences, LPHNs based anti-cancer drug delivery, conventional and modern preparation methods as well as their drug loading and entrapment efficiencies. In addition, this article also gives an insight into the mechanistic approach to oral bioavailability enhancement, potential applications in anti-cancer drug delivery, limitations, and future prospects of LPHNs in anti-cancer drug delivery. Full article

Cannabinoids are widely recognized for their potential therapeutic effects, making them significant and valuable candidates for medical research and applications across various fields. This review aims to analyze the pharmacokinetics of Cannabidiol (CBD), Cannabigerol (CBG), and Cannabichromene (CBC), along with their corresponding acidic forms, Cannabidiolic acid (CBDA), Cannabigerolic acid (CBGA), and Cannabichromenic acid (CBCA). Among these cannabinoids, CBD is the most extensively studied. Nevertheless, research involving all the mentioned cannabinoids has shown that their pharmacokinetic parameters are highly variable, depending significantly on factors such as dose, formulation, route of administration, and diet. Furthermore, challenges such as brain penetration and first-pass metabolism have been highlighted. In conclusion, this review demonstrates significant progress in understanding the pharmacokinetics of non-psychotropic cannabinoids. However, it also underscores the need for further research, particularly on CBG, CBC, and their respective acidic forms, with the most significant gap being in clinical investigations. Expanding these studies is essential to facilitate their optimized use in medical treatments. Full article