ADMET and DMPK最新文献

Background and purpose: The main features of the dynamics of the glucocorticoid receptor (GR) have been known for 50 years: 1) in the absence of glucocorticoid (G), the receptor is localized entirely in the cytoplasm; 2) upon G binding, GR is converted into a tightly bound G form and is rapidly imported into the nucleus where it can bind DNA and modulate transcription; 3) nuclear export of GR is very slow; and 4) the nuclear form of GR can recycle through an unbound form, back to the bound transcription modulating form without leaving the nucleus.

Experimental approach: A kinetic model that captures these features is presented, a set of model parameters for dexamethasone is derived, and the clinical implication for the commonly used glucocorticoids is discussed.

Key results: At the high concentrations normally used to describe G pharmacodynamics, the model reduces to the standard Michaelis-Menten equation with a K _m that is a function of 4 model parameters. At very low concentrations, it reduces to another Michaelis-Menten equation with about a 1000-fold greater affinity, eg. at the nadir human endogenous cortisol concentration, the full model GR activity is 2.6 times greater than that predicted by extrapolation of the high concentration results.

Conclusion: The model is used to relate normal human 24-hour endogenous plasma cortisol levels to transcriptional activity and is applied to the commonly prescribed glucocorticoids (dexamethasone, methylprednisolone, prednisone) in an attempt to provide a pharmacological rationale for the very large therapeutic dosage range that has been traditionally used.

Background and purpose: Cyclophosphamide (CP) is a widely used antitumor and immunosuppressive drug, but it is highly cytotoxic and has carcinogenic and teratogenic potential. To reduce adverse effects of CP therapy and the frequency of its administration, the microencapsulation of CP into biodegradable polymeric matrices can be performed. However, according to the literature, only a few polymers were found suitable to encapsulate CP and achieve its' sustained release.

Experimental approach: In this research, spray-dried cyclophosphamide-loaded poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microparticles were prepared and characterized in terms of their average hydrodynamic diameter, polydispersity index, surface morphology, zeta potential, encapsulation efficiency, drug loading, thermal properties and cytotoxicity against 3T3 cells.

Key results: The obtained CP-loaded microparticles had a regular spherical shape, uniform size distribution with an average diameter of 4.21±0.04 μm and zeta potential of -34.2±0.2 mV. The encapsulation of cyclophosphamide into the PHBV matrix led to a decrease in melting and degradation temperatures and an increase in diameter, glass transition and cold crystallization temperatures compared to blank microparticles. Moreover, microencapsulation of cyclophosphamide lowered its cytotoxicity compared to the pure drug: the number of dead cells in the culture decreased by 28 %, while their metabolic activity increased by 20 %. The cumulative in vitro drug release studies showed a gradual release of CP up to 18 days, so the obtained microparticle formulation can be used as a sustained-release cyclophosphamide delivery system.

Conclusion: In this research, a novel cyclophosphamide-loaded platform based on PHBV microparticles was established and characterized. Overall, this study offers promising prospects for cancer therapy in the future.

Background and purpose: The study explores basil seed mucilage as a bioadhesive carrier for naproxen sodium, demonstrating its ability to enhance solubility when administered rectally. The mucilage, derived from Ocimum basilicum seeds, showed bioadhesive properties and thermal stability, as confirmed by FTIR spectroscopy and X-ray diffraction analysis.

Experimental approach: Microspheres were prepared using a double emulsion solvent evaporation technique, varying polymer ratios to optimize drug delivery.

Key results: Particle size analysis revealed a range of 456±0.51 to 712±0.21 μm, with larger microspheres formed at higher mucilage concentrations due to increased viscosity. Encapsulation efficiency ranged from 45.01±0.25 % to 79.4±0.93 %, improving with higher basil/alginate ratios. The superior batch, OBM5, showed excellent mucoadhesive qualities in ex-vivo assays, attributed to the increased polymer content, facilitating interaction with rectal mucosa. SEM analysis of OBM5 indicated a spherical, monolithic structure conducive to free flow. Drug release was efficient, with OBM5 achieving 88.7±1.3 % after 7 hours, indicating a controlled release profile.

Conclusion: Incorporated into polyethylene glycol (PEG) 4000 suppositories, supposetories were completely disintegrated in buffer solution within 25 minutes. The bioadhesive force of basil seed mucilage on rectal mucosa was significantly enhanced, reaching 6.44±0.58 g, correlating with mucilage concentration. These findings underscore the efficacy of basil seed mucilage as a bioadhesive biopolymer for rectal drug delivery systems.

Background and purpose: Trichosanthin (TCS) is a plant-based ribosome-inactivating protein exhibiting a range of pharmacological properties, including abortifacient and anticancer. However, the routine clinical use in cancer treatment was hampered by its antigenicity. Hexokinase 2 (HK2) is a pivotal regulator of glycolysis, where aberrant expression is observed in many cancers. This study investigates the anticancer effects and mechanisms of TCS in combination with benserazide (Benz), a HK2 inhibitor, in Hela and SCC25 cancer models.

Experimental approach: MTT, colony-formation and cell cycle assays were performed to assess the cytotoxic effects of TCS and Benz in HeLa and SCC25 cells. Seahorse assay, western blotting, flow cytometry analysis and RNA sequencing were employed to investigate the pharmacological effects of the combo treatment. SCC25 cell xenograft mouse model was established for in vivo efficacy study.

Key results: Combined use of TCS and Benz exhibited synergistic anticancer effects in both Hela and SCC25 cell models. The observed synergistic effects were attributed to the modulation of glycolysis by targeting HK2, leading to reduced lactate production and increased ROS accumulation which further inhibited colony formation and cell cycle progression, as well as triggered apoptosis. Moreover, this combination effectively inhibited NFκB/ERK signalling pathways, which were found to be significantly activated upon single use of TCS. It was found that the combination significantly suppressed the tumour growth in SCC25 cell xenograft mouse model.

Conclusion: Our findings suggested that targeting HK2 and modulating glycolysis may offer a promising avenue for improving the therapeutic outcomes of TCS-based anticancer treatments.

Background and purpose: Organic UV filters are commonly used in sunscreen and cosmetic formulations to protect against harmful UV radiation. However, concerns have emerged over their potential toxic effects on aquatic organisms. This study aims to investigate the acute aquatic toxicity of 13 organic UV filters and determine whether phospholipid binding, measured through biomimetic chromatographic methods, is a better predictor of toxicity than the traditionally used octanol-water partition coefficient (log P).

Experimental approach: The chromatographic retention of the 13 UV filters was measured on an immobilized artificial membrane (IAM) stationary phase to assess phospholipid binding. These measurements were then applied to previously established predictive models, originally developed for pharmaceutical compounds, to estimate acute aquatic toxicity endpoints of 48-hour LC₅₀ for fish and the 48-hour EC₅₀ (immobilization) for Daphnia magna.

Key results: Phospholipid binding was found to be a more reliable predictor of the acute aquatic toxicity of UV filters compared to log P. The toxicity was primarily driven by lipophilicity and charge, with negatively charged compounds exhibiting lower toxicity.

Conclusion: The study demonstrates that phospholipid binding is a better descriptor of UV filter toxicity than log P, providing a more accurate method for predicting the environmental risk of these compounds. This insight can guide the development of more environmentally friendly sunscreens by reducing the use of highly lipophilic and positively charged compounds, thus lowering their aquatic toxicity.

Background and purpose: Methotrexate (MTX) is a widely used anti-cancer drug, but its overuse can lead to significant side effects. Therefore, it is very vital to design simple and sensitive analytical methods for its determination.

Experimental approach: In this work, an electrochemical sensor was prepared based on an ionic liquid (IL)/Ni-Co layered double hydroxide nanosheets (Ni-Co-LDH)-modified carbon paste electrode IL/Ni-Co-LDH/CPE. Cyclic voltammetry, differential pulse voltammetry, and chronoamperometry methods were applied to evaluate the performance of the designed sensor for MTX determination.

Key results: The IL/Ni-Co-LDH/CPE sensor exhibits a linear relationship between the peak current of the differential pulse voltammetry and MTX concentrations in the linear dynamic range of 0.02 to 140.0 μM, with a detection limit of 0.006 μM. The IL/Ni-Co-LDH/CPE sensor exhibited relative standard deviation values between 1.7 to 3.7 % for recovery tests on real samples, indicating the precision of the method.

Conclusion: The designed sensor with cost-effective and good performance could be valuable for therapeutic drug monitoring and clinical diagnostics.

Background and purpose: The food effects on oral drug absorption are challenging to predict from in vitro data. Food intake has been reported to reduce the oral absorption of several zwitterionic antihistamine drugs. However, the mechanism for this negative food effect has not been clear. The purpose of the present study was to evaluate the bile micelle and food binding of zwitterionic antihistamine drugs as a possible mechanism for the negative food effects on their oral drug absorption.

Experimental approach: Bilastine (BIL), cetirizine (CET), fexofenadine (FEX), and olopatadine (OLO) were employed as model drugs. The fed/fasted AUC ratios of BIL, CET, FEX, and OLO after oral administration are reported to be 0.60 to 0.7, 0.92, 0.76 to 0.85, and 0.84, respectively. The unbound fraction (f _u) of these drugs in the fasted and fed state simulated intestinal fluids (FaSSIF and FeSSIF, containing 3 and 15 mM taurocholic acid, respectively) with or without FDA breakfast homogenate (BFH) was measured by dynamic dialysis.

Key results: The FeSSIF/ FaSSIF f_u ratios were 0.90 (BIL), 0.46 (CET), 0.76 (FEX), and 0.78 (OLO). In the presence of BFH, the f_u ratios were reduced to 0.52 (BIL), 0.22 (CET), 0.39 (FEX), and 0.44 (OLO).

Conclusion: Despite being zwitterion at pH 6.5, the antihistamine drugs were bound to bile micelles. Bile micelle and food binding were suggested to cause a negative food effect on the oral absorption of these drugs. However, the AUC ratio was not quantitatively predicted by using FeSSIF + BFH.

Background and purpose: The classical drug discovery toolbox continually expands beyond traditional rule of five (Ro5)-compliant small molecules to include new chemical modalities for difficult-to-drug targets. The paper focuses on the molecular properties essential to drive oral bioavailability within the bRo5 framework.

Experimental approach: The first part outlines the concept and methodologies for characterizing bRo5 physicochemical properties, including considerations on chameleonicity; in particular, the paper summarizes the content of the last author's talk presented during the IAPC-10 Meeting held in Belgrade in September 2023 (https://iapchem.org/index.php/iapc-10-home). The second part of the manuscript presents novel experimental and computational data on three proteolysis targeting chimeras (PROTACs) currently in clinical trials.

Key results: Molecular descriptors of ARV-110, ARV-471, and DT-2216 are reported and the main limitations of the applied experimental approaches are discussed. Moreover, a simple computational method shows how predicting the presence of chameleonic effects.

Conclusion: A full complete physicochemical characterization of three degraders in clinical trials is reported to highlight the differences in physicochemical descriptors between PROTACs dosed orally and intravenously.

Background and purpose: Chronic myeloid leukaemia (CML) is one of the most lethal types of leukaemia and can rapidly progress if not treated properly. Therefore, having an effective diagnostic strategy is crucial. Various methods are available for diagnosis, including electrochemical biosensors with aptamer bioreceptors.

Experimental approach: In this study, we immobilized the KK1D04 aptamer on a screen-printed carbon electrode (SPCE) supported by CeO₂ nanoparticles (CeO₂NPs) to detect K562 cells, a type of CML cell line. Several parameters were optimized to enhance the aptasensor response using the Box-Behnken experimental design.

Key results: The developed aptasensor demonstrated good performance with a limit of detection (LOD) and limit of quantification (LOQ) of 16 cells/mL and 3,882 cells/mL, respectively, in the K562 cell concentration range of 10² to 10⁶ cells/mL. The optimum experimental conditions were an aptamer concentration of 0.8 ppm, an aptamer incubation time of 36 minutes, and a K562 aptamer-cell incubation time of 13 minutes. The aptasensor also exhibits selectivity for K562 cells compared to Vero cells, THP1 cells, and Raji cells.

Conclusion: The aptasensor in this study demonstrated the potential to detect K562 cells. These results could contribute to the advancement of point-of-care (POC) devices for the detection of CML.

Background and purpose: Aiming to achieve light sedation via intranasal administration, this study showed that propofol (PPF) did not permeate across the rabbit nasal mucosa ex vivo from its marketed emulsion for injection.

Experimental approach: Dilution of the emulsion with methyl-β-cyclodextrin in saline solution increased propofol solubility in water and diffusion across the nasal epithelium.

Key results and conclusion: Despite these positive effects of the cyclodextrin, the amount of PPF permeated was minimal in 3 h, exceeding the formulation residence time in the nose. These results highlight the key role of formulation and the need for innovation in solubility and transmucosal transport enhancement techniques to optimize drug delivery and therapeutic efficacy.