Pharmaceutical Research最新文献

Background: Digoxin is a commonly used cardiac glycoside drug in clinical practice, primarily transported by P-glycoprotein (P-gp) and susceptible to the influence of P-gp inhibitors/inducers. Concurrent administration of ritonavir and digoxin may significantly increase the plasma concentration of digoxin. Due to the narrow therapeutic window of digoxin, combined use may lead to severe toxic effects.

Purpose: Utilize a Physiology-Based Pharmacokinetic (PBPK) model to simulate and predict the impact of the interaction between ritonavir and digoxin on the pharmacokinetics (PK) of digoxin, and provide recommendations for the combined medication regimen.

Methods: Using PK-Sim^®, develop individual PBPK models for ritonavir and digoxin. Simulate the exposure in a drug-drug interaction (DDI) scenario by implementing ritonavir's inhibition of P-glycoprotein (P-gp) on digoxin. Evaluate the performance of the models by comparing the predicted and observed plasma concentration-time curves and predicted versus observed PK parameter values. Finally, adjust the dosing regimen for the combined therapy based on the changes in exposure.

Results: According to the model simulations, the steady-state exposure of digoxin increased by 86.5% and 90.2% for oral administration, and 80.2% and 90.2% for intravenous administration, respectively, when 0.25 mg or 0.5 mg of digoxin was administered concurrently with ritonavir. By reducing the dose of digoxin by 45% or doubling the oral administration interval, similar steady-state concentrations can be achieved compared to when the drugs are not co-administered.

Conclusions: In clinical practice, the influence of drug interactions on the plasma concentration changes of digoxin within the body should be considered to ensure the safety and effectiveness of treatment.

Purpose: Amino acid transporters are expressed in the brain capillary endothelial cells that form the blood-brain barrier (BBB), and their expression levels change during the neonatal period. This study aimed to investigate the molecular mechanisms regulating amino acid transporter levels in mouse brain capillary endothelial cells.

Methods: Capillaries were isolated from the brains of neonatal and adult mice. Activation of eukaryotic translation initiation factor 2α kinase 4 (eIF2αK4) was analyzed in MBEC4 (mouse brain capillary endothelial) cells under amino acid-depleted conditions. Protein expression was determined using western blotting and proteomic analyses.

Results: Phosphorylation of eIF2α, a downstream target of eIF2αK4, was induced in the brain capillaries of neonates compared to adults. In vitro experiments using MBEC4 cells revealed that amino acid depletion induced eIF2α phosphorylation and expression of the amino acid transporter, solute carrier (Slc)-7a1. The eIF2αK4 inhibitor, GCN2iB, inhibited these inductions. Proteomic analysis revealed arginine depletion-dependent induction of amino acid transporters Slc1a4, Slc3a2, Slc7a1, Slc7a5, and Slc38a1. These effects were also inhibited by GCN2iB, suggesting the involvement of eIF2αK4 activation. In contrast, the expression of Slc2a1, Slc16a1, Abcb1b, Abcg2, transferrin receptor, insulin receptor, claudin-1, ZO-1, and Jam1 was not suppressed by the GCN2iB treatment.

Conclusions: Overall, the eIF2αK4 pathway plays a regulatory role in amino acid transporter expression in brain capillary endothelial cells and facilitates the maintenance of amino acid homeostasis in the brain. This study provides new insights into the regulatory mechanisms underlying nutrient transport across the BBB.

Purpose: Since the first human experience in space, the interest in space research and medicine to explore universe is growing day by day. The extreme space conditions mainly radiation and microgravity effects on human physiology, antimicrobial susceptibility, and efficacy, safety, and stability of drugs. Therefore, the aim of this review is to address the impact of extreme space conditions, mainly microgravity and radiation, on human physiology and highlights the need for future approaches by evaluating the effectiveness of strategies to prevent or mitigate health problems.

Methods: Published papers and NASA technical documents were searched in Pubmed and Google Scholar databases using the keywords ''antimicrobial susceptibility or drug resistance or drug stability or innovations or pharmacokinetic or pharmacodynamics'' and ''radiation or microgravity or space environments or space medicine or space pharmacy'' to prepare this review.

Results: In this review, the challenges regarding physiological effects and drug-related problems are examined through the evaluation of extreme conditions in space. Medications used in spaceflight are summarized, and the role of pharmacists specializing in space medicine is briefly explained. Last but not least, to overcome the aforementioned issues, novel approaches have been addressed, such as personalised treatments, development of space-resistant formulations and various microbial applications.

Conclusions: Further research in the space medicine is required to facilitate the safe and healthy travel of humans to the Moon, Mars and other extraterrestrial destinations. One bear in mind that space research will contribute not only to the exploration of the universe, but also to the advancement of health and technological discoveries on Earth.

Purpose: This study aimed to develop a new index, Distribution Uniformity Index (DUI), to assess the "intra-tablet" homogeneity.

Methods: High-resolution hyperspectral Raman imaging was adopted to scan a tablet to get the components' distribution. The heuristic algorithm was applied to generate a Raman heatmap with RGB colors quantitatively correlated with the concentrations of each component. DUI is defined as the ratio of the area under the uniformity curve of the sample image to that of the randomized image. The accuracy and applicability of DUI were verified by constructing model images with controlled uniformity and random regions. The effects of "intra-tablet" homogeneity on the disintegration and dissolution of spironolactone tablets were investigated.

Results: DUI value was directly obtained from heuristic visual analysis of macro-pixel from hyperspectral Raman images. A good linear relationship and good repeatability were confirmed between DUI and the uniformity of model images. The size of CaSO₄·2H₂O affected the "intra-tablet" homogeneity of spironolactone tablets, which was detected by the DUI value. The better "intra-tablet" homogeneity led to a higher disintegration and dissolution of spironolactone tablets.

Conclusions: DUI represents a novel index to evaluate the "intra-tablet" homogeneity and is beneficial for formulation research and development.

Embedded within the field of drug metabolism and pharmacokinetics (DMPK), biotransformation is a discipline that studies the origins, disposition, and structural identity of metabolites to provide a comprehensive safety assessment, including the assessment of exposure coverage in toxicological species. Spanning discovery and development, metabolite identification (metID) scientists employ various strategies and tools to address stage-specific questions aimed at guiding the maturation of early chemical matter into drug candidates. During this process, the identity of major (and minor) circulating human metabolites is ascertained to comply with the regulatory requirements such as the Metabolites in Safety Testing (MIST) guidance. Through the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ), the "Translatability of MetID In Vitro Systems Working Group" was created within the Translational and ADME Sciences Leadership Group. The remit of this group was to objectively determine how accurate commonly employed in vitro systems have been with respect to prediction of circulating human metabolites, both qualitatively and quantitatively. A survey composed of 34 questions was conducted across 26 pharmaceutical companies to obtain a foundational understanding of current metID practices, preclinically and clinically, as well as to provide perspective on how successful these practices have been at predicting circulating human metabolites. The results of this survey are presented as an initial snapshot of current industry-based metID practices, including our perspective on how a harmonized framework for the conduct of in vitro metID studies could be established. Future perspectives from current practices to emerging advances with greater translational capability are also provided.

Objective: Glutamate transporters play a key role in central nervous system physiology by maintaining excitatory neurotransmitter homeostasis. Biological assemblies of the transporters, consisting of cyclic homotrimers, emerge as a crucial aspect of glutamate transporter modulation. Hence targeting heteromerization promises an effective approach for modulator design. On the other hand, the dynamic nature of transcription allows for the generation of transporter isoforms in structurally distinct manners.

Methods: The potential isoforms were identified through the analysis of computationally generated gene-centric isoform maps. The conserved features of isoform sequences were revealed by computational chemistry methods and subsequent structural analysis of AlphaFold2 predictions. Truncated isoforms were further subjected to a wide range of docking analyses, 50ns molecular dynamics simulations, and evolutionary coupling analyses.

Results: Energetic landscapes of isoform-canonical transporter complexes suggested an inhibitory potential of truncated isoforms on glutamate transporter bio-assembly. Moreover, isoforms that mimic the trimerization domain (in particular, TM2 helices) exhibited stronger interactions with canonical transporters, underscoring the role of transmembrane helices in isoform interactions. Additionally, self-assembly dynamics observed in truncated isoforms mimicking canonical TM5 helices indicate a potential protective role against unwanted interactions with canonical transporters.

Conclusion: Our computational studies on glutamate transporters offer insights into the roles of alternative splicing on protein interactions and identifies potential drug targets for physiological or pathological processes.

Objective: The oral absorption of a peptide is driven by a high local concentration of a permeation enhancer (PE) in the gastrointestinal tract. We hypothesized that a controlled release of both PE and peptide from a solid formulation, capable of maintaining an effective co-localized concentration of PE and peptide could enhance oral peptide absorption. In this study, we aimed to develop a 3D-printed two-compartment capsular device with controlled pulsatile release of peptide and sodium caprate (C10).

Methods: 3D-printed two-compartment capsular device was fabricated using a fused deposition modeling method. This device was then filled with LY peptide and C10. The release profile was modulated by changing the thickness and polymer type of the capsular device. USP apparatus II dissolution test was used to evaluate the impacts of device thickness and polymer selection on release profile in vitro. An optimal device was then enteric coated with HPMCAS.

Results: A strong linear relationship between the thickness of capsular devices and the delay in the release onset time was observed. An increase in the device thickness or the use of PLA decreased the release rate. The capsular device with compartment 1, compartment 2 and fence thickness of 0.4; 0.95 and 0.5 mm, respectively, and the use of PVA achieved desired pulsatile release profiles of both peptide and C10. Furthermore, enteric-coated capsular devices with HPMCAS had similar pulsatile release profiles compared to non-enteric coated devices.

Conclusion: These findings suggest potential application of 3D-printing techniques in the formulation development for complex modified drug release products.

Objective: To explore the potential of transnasal drug delivery systems (DDS) as an effective means of bypassing the bloodbrain barrier (BBB) for enhanced central nervous system (CNS) targeting, aiming to improve therapeutic outcomes for CNS disorders while reducing systemic side effects.

Methods: A review of current and emerging DDS technologies, including polymer nanoparticles, liposomes, and micelles, was conducted to assess their suitability for precision-targeted delivery to the brain through the transnasal route.

Results: The investigated DDS demonstrate promising capabilities for CNS targeting via the nasal pathway, effectively preserving both the nasal mucosa and CNS integrity. These systems enhance drug precision within neural tissues, potentially improving therapeutic outcomes without harming adjacent tissues.

Conclusions: Transnasal DDS offer a promising alternative to traditional delivery methods, with significant potential to advance the treatment of cerebrovascular diseases, neurodegenerative disorders, brain tumors, and psychiatric conditions. This approach represents an evolving frontier in neurotherapeutics, with the potential to transform CNS drug delivery practices.

Background: Metabolism reprogramming is a crucial hallmark of malignant tumors. Tumor cells demonstrate enhanced metabolic efficiency, converting nutrient inputs into glucose, amino acids, and lipids essential for their malignant proliferation and progression. Metformin, a commonly prescribed medication for type 2 diabetes mellitus, has garnered attention for its potential anticancer effects beyond its established hypoglycemic benefits.

Methods: This review adopts a comprehensive approach to delineate the mechanisms underlying metabolite abnormalities within the primary metabolic processes of malignant tumors.

Results: This review examines the abnormal activation of G protein-coupled receptors (GPCRs) in these metabolic pathways, encompassing aerobic glycolysis with increased lactate production in glucose metabolism, heightened lipid synthesis and cholesterol accumulation in lipid metabolism, and glutamine activation alongside abnormal protein post-translational modifications in amino acid and protein metabolism. Furthermore, the intricate metabolic pathways and molecular mechanisms through which metformin exerts its anticancer effects are synthesized and analyzed, particularly its impacts on AMP-activated protein kinase activation and the mTOR pathway. The analysis reveals a multifaceted understanding of how metformin can modulate tumor metabolism, targeting key nodes in metabolic reprogramming essential for tumor growth and progression. The review compiles evidence that supports metformin's potential as an adjuvant therapy for malignant tumors, highlighting its capacity to interfere with critical metabolic pathways.

Conclusion: In conclusion, this review offers a comprehensive overview of the plausible mechanisms mediating metformin's influence on tumor metabolism, fostering a deeper comprehension of its anticancer mechanisms. By expanding the clinical horizons of metformin and providing insight into metabolism-targeted tumor therapies, this review lays the groundwork for future research endeavors aimed at refining and advancing metabolic intervention strategies for cancer treatment.

Purpose: The application of 3D printing technology in drug delivery is often limited by the challenges of achieving precise control over drug release profiles. The goal of this study was to apply surface equations to construct 3D printed tablet models, adjust the functional parameters to obtain multiple tablet models and to correlate the model parameters with the in vitro drug release behavior.

Methods: This study reports the development of 3D-printed tablets using surface geometries controlled by mathematical functions to modulate drug release. Utilizing fused deposition modeling (FDM) coupled with hot-melt extrusion (HME) technology, personalized drug delivery systems were produced using thermoplastic polymers. Different tablet shapes (T1-T5) were produced by varying the depth of the parabolic surface (b = 4, 2, 0, -2, -4 mm) to assess the impact of surface curvature on drug dissolution.

Results: The T5 formulation, with the greatest surface curvature, demonstrated the fastest drug release, achieving complete release within 4 h. In contrast, T1 and T2 tablets exhibited a slower release over approximately 6 h. The correlation between surface area and drug release rate was confirmed, supporting the predictions of the Noyes-Whitney equation. Differential Scanning Calorimetry (DSC) and Scanning Electron Microscope (SEM) analyses verified the uniform dispersion of acetaminophen and the consistency of the internal structures, respectively.

Conclusions: The precise control of tablet surface geometry effectively tailored drug release profiles, enhancing patient compliance and treatment efficacy. This novel approach offers significant advancements in personalized medicine by providing a highly reproducible and adaptable platform for optimizing drug delivery.