Improved In vivo Effect of Chrysin as an Absorption Enhancer Via the Preparation of Ternary Solid Dispersion with Brij®L4 and Aminoclay

Mechanochemical Approach to Obtaining a Multicomponent Fisetin Delivery System Improving Its Solubility and Biological Activity

In this study, binary amorphous solid dispersions (ASDs, fisetin-Eudragit®) and ternary amorphous solid inclusions (ASIs, fisetin-Eudragit®-HP-β-cyclodextrin) of fisetin (FIS) were prepared by the mechanochemical method without solvent. The amorphous nature of FIS in ASDs and ASIs was confirmed using XRPD (X-ray powder diffraction). DSC (Differential scanning calorimetry) confirmed full miscibility of multicomponent delivery systems. FT-IR (Fourier-transform infrared analysis) confirmed interactions that stabilize FIS's amorphous state and identified the functional groups involved. The study culminated in evaluating the impact of amorphization on water solubility and conducting in vitro antioxidant assays: 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)-ABTS, 2,2-diphenyl-1-picrylhydrazyl-DPPH, Cupric Reducing Antioxidant Capacity-CUPRAC, and Ferric Reducing Antioxidant Power-FRAP and in vitro neuroprotective assays: inhibition of acetylcholinesterase-AChE and butyrylcholinesterase-BChE. In addition, molecular docking allowed for the determination of possible bonds and interactions between FIS and the mentioned above enzymes. The best preparation turned out to be ASI_30_EPO (ASD fisetin-Eudragit® containing 30% FIS in combination with HP-β-cyclodextrin), which showed an improvement in apparent solubility (126.5 ± 0.1 µg∙mL-1) and antioxidant properties (ABTS: IC50 = 10.25 µg∙mL-1, DPPH: IC50 = 27.69 µg∙mL-1, CUPRAC: IC0.5 = 9.52 µg∙mL-1, FRAP: IC0.5 = 8.56 µg∙mL-1) and neuroprotective properties (inhibition AChE: 39.91%, and BChE: 42.62%).

Enhanced Antioxidant and Neuroprotective Properties of Pterostilbene (Resveratrol Derivative) in Amorphous Solid Dispersions

In this study, amorphous solid dispersions (ASDs) of pterostilbene (PTR) with polyvinylpyrrolidone polymers (PVP K30 and VA64) were prepared through milling, affirming the amorphous dispersion of PTR via X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC). Subsequent analysis of DSC thermograms, augmented using mathematical equations such as the Gordon-Taylor and Couchman-Karasz equations, facilitated the determination of predicted values for glass transition (Tg), PTR's miscibility with PVP, and the strength of PTR's interaction with the polymers. Fourier-transform infrared (FTIR) analysis validated interactions maintaining PTR's amorphous state and identified involved functional groups, namely, the 4'-OH and/or -CH groups of PTR and the C=O group of PVP. The study culminated in evaluating the impact of amorphization on water solubility, the release profile in pH 6.8, and in vitro permeability (PAMPA-GIT and BBB methods). In addition, it was determined how improving water solubility affects the increase in antioxidant (ABTS, DPPH, CUPRAC, and FRAP assays) and neuroprotective (inhibition of cholinesterases: AChE and BChE) properties. The apparent solubility of the pure PTR was ~4.0 µg·mL-1 and showed no activity in the considered assays. For obtained ASDs (PTR-PVP30/PTR-PVPVA64, respectively) improvements in apparent solubility (410.8 and 383.2 µg·mL-1), release profile, permeability, antioxidant properties (ABTS: IC50 = 52.37/52.99 μg·mL-1, DPPH: IC50 = 163.43/173.96 μg·mL-1, CUPRAC: IC0.5 = 122.27/129.59 μg·mL-1, FRAP: IC0.5 = 95.69/98.57 μg·mL-1), and neuroprotective effects (AChE: 39.1%/36.2%, BChE: 76.9%/73.2%) were confirmed.

Flavonoids in the Spotlight: Bridging the Gap between Physicochemical Properties and Formulation Strategies

Flavonoids are hydroxylated polyphenols that are widely distributed in plants with diverse health benefits. Despite their popularity, the bioavailability of flavonoids is often overlooked, impacting their efficacy and the comparison of products. The study discusses the bioavailability-related physicochemical properties of flavonoids, with a focus on the poorly soluble compounds commonly found in dietary supplements and herbal products. This review sums up the values of pKa, log P, solubility, permeability, and melting temperature of flavonoids. Experimental and calculated data were compiled for various flavonoid subclasses, revealing variations in their physicochemical properties. The investigation highlights the challenges posed by poorly soluble flavonoids and underscores the need for enabling formulation approaches to enhance their bioavailability and therapeutic potential. Compared to aglycones, flavonoid glycosides (with sugar moieties) tend to be more hydrophilic. Most of the reviewed aglycones and glycosides exhibit relatively low log P and high melting points, making them "brick dust" candidates. To improve solubility and absorption, strategies like size reduction, the potential use of solid dispersions and carriers, as well as lipid-based formulations have been discussed.

The Amorphous Solid Dispersion of Chrysin in Plasdone® S630 Demonstrates Improved Oral Bioavailability and Antihyperlipidemic Performance in Rats

Chrysin is a flavonoid with various biological activities. However, its low water solubility and strong metabolism render its oral bioavailability rather poor. This study aimed to develop a stable solid dispersion formulation of chrysin to improve the dissolution of chrysin, so as to increase its oral bioavailability and improve its antihyperlipidemic activities. A solid dispersion of chrysin was prepared using a solvent evaporation method, with Plasdone® S630 as the hydrophilic carrier. The formulations were characterized via X-ray diffraction, in vitro dissolution studies, and stability studies. An in-situ perfusion model was used to evaluate the absorption rates. Plasma pharmacokinetics and antihyperlipidemic performance after the oral administration of the chrysin formulations were investigated in rats. It was found that the solid dispersion of chrysin prepared using the drug-polymer mass ratio of 1:6 can form the optimized formulation. X-ray diffraction results showed that the chrysin was in an amorphous state in this optimized formulation. The cumulative release percentage of the optimized solid dispersion of chrysin at pH 1.2 and pH 6.8 was elevated to above 90% within 24 h, indicating that the formulation could enhance the dissolution rates of chrysin. Stability studies showed that the optimized formulation presented acceptable long-term storage stability, but it was susceptible to high temperature and humidity. The solid dispersion of chrysin showed higher absorption rates in the in-situ perfusion model. Pharmacokinetic studies revealed that Cmax and AUC after the intragastric administration of solid dispersion of chrysin were appreciably higher than those resulting from chrysin suspension. The oral bioavailability of the solid dispersion of chrysin was 41 times higher than that of chrysin suspension. Pharmacological studies suggested that the solid dispersion of chrysin was more powerful than chrysin raw material in improving biochemical indicators in the hyperlipidemic model in rats. This study reveals the potential use of a novel oral formulation of chrysin to reduce the currently required high dose.

Chrysin-phospholipid complex-based solid dispersion for improved anti-aging and neuroprotective effects in mice

The present study aimed to improve the neuroprotective effect of chrysin (CHR) by combining two formulation techniques, phospholipid (PL) complexation and solid dispersion (SD). CHR-phospholipid complex (CHR-PLC) was prepared through solvent evaporation. The molar ratio CHR/PL (1:3), which exhibited the highest complexation efficiency, was selected for the preparation of CHR-PLC loaded SD (CHR-PLC-SD) with 2-hydroxypropyl β cyclodextrin (2-HPβCD) and polyvinylpyrrolidone 8000. CHR-PLC/2-HPβCD (1:2, w/w) displayed the highest aqueous solubility of CHR (5.86 times more than that of plain CHR). CHR-SD was also prepared using 2-HPβCD for comparison. The in vitro dissolution of CHR-PLC-SD4 revealed an enhancement in the dissolution rate over CHR-PLC (1:3), CHR-SD, and plain CHR by six times. The optimum formulations and plain CHR were evaluated for their neuroprotective effect on brain aging induced by D-galactose in mice. The results demonstrated a behavioral activity elevation, an increase of AMPK, LKB1, and PGC1α brain contents as well as a reduction of AGEs, GFAP, NT-3, TNF-α, and NF-κβ brain contents when compared with those of the D-galactose control group. Thus, the developed formulations stimulated neurogenesis and mitochondrial biogenesis as well as suppressed neuroinflammation and neurodegeneration. The order of activity was as follows: CHR-PLC-SD4 > CHR-PLC (1:3) > CHR-SD > plain CHR.

Current Trends on Solid Dispersions: Past, Present, and Future

Solid dispersions have achieved significant interest as an effective means of enhancing the dissolution rate and thus the bioavailability of a range of weakly water-soluble drugs. Solid dispersions of weakly water-soluble drugs with water-soluble carriers have lowered the frequency of these problems and improved dissolution. Solid dispersion is a solubilization technology emphasizing mainly on, drug-polymer two-component systems in which drug dispersion and its stabilization is the key to formulation development. Therefore, this technology is recognized as an exceptionally useful means of improving the dissolution properties of poorly water-soluble drugs and in the latest years, a big deal of understanding has been accumulated about solid dispersion, however, their commercial application is limited. In this review article, emphasis is placed on solubility, BCS classification, and carriers. Moreover, this article presents the diverse preparation techniques for solid dispersion and gathers some of the recent technological transfers. The different types of solid dispersions based on the carrier used and molecular arrangement were underlined. Additionally, it summarizes the mechanisms, the methods of preparing solid dispersions, and the marketed drugs that are available using solid dispersion approaches.

Improving Anticancer Activity of Chrysin using Tumor Microenvironment pH-Responsive and Self-Assembled Nanoparticles

Chrysin is a natural bioactive compound with potential biological activities. However, unfavorable physicochemical properties of native chrysin make it difficult to achieve good therapeutic efficacies. In this study, poly(ethylene) glycol (PEG₄₀₀₀)-conjugated chrysin nanoparticles were prepared. The PEG₄₀₀₀ was conjugated to chrysin through cis-aconityl and succinoyl linkers to achieve tumor microenvironment-specific drug release from PEGylated nanoparticles. The conjugation of PEG and chrysin via succinoyl (PCNP-1) and cis-aconityl (PCNP-2) linkers was confirmed by the ¹H NMR and FTIR analysis. The nanoparticles were characterized by DLS, TEM, XRD, and DSC analysis. Comparatively, PCNP-2 showed a better drug release profile and higher anticancer activity against human breast cancer cells than chrysin or PCNP-1. The apoptosis studies and colony formation inhibition assay revealed that the PCNP-2 induced more apoptosis and more greatly controlled the growth of human breast cancer cells than pure chrysin. Thus, the use of PCNPs may help to overcome the issues of chrysin and could be a better therapeutic approach.

Pharmacokinetics and drug-likeness of antidiabetic flavonoids: Molecular docking and DFT study

Computer aided toxicity and pharmacokinetic prediction studies attracted the attention of pharmaceutical industries as an alternative means to predict potential drug candidates. In the present study, in-silico pharmacokinetic properties (ADME), drug-likeness, toxicity profiles of sixteen antidiabetic flavonoids that have ideal bidentate chelating sites for metal ion coordination were examined using SwissADME, Pro Tox II, vNN and ADMETlab web tools. Density functional theory (DFT) calculations were also employed to calculate quantum chemical descriptors of the compounds. Molecular docking studies against human alpha amylase were also conducted. The results were compared with the control drugs, metformin and acarbose. The drug-likeness prediction results showed that all flavonoids, except myricetin, were found to obey Lipinski's rule of five for their drug like molecular nature. Pharmacokinetically, chrysin, wogonin, genistein, baicalein, and apigenin showed best absorption profile with human intestinal absorption (HIA) value of ≥ 30%, compared to the other flavonoids. Baicalein, butein, ellagic acid, eriodyctiol, Fisetin and quercetin were predicted to show carcinogenicity. The flavonoid derivatives considered in this study are predicted to be suitable molecules for CYP3A probes, except eriodyctiol which interacts with P-glycoprotein (p-gp). The toxicological endpoints prediction analysis showed that the median lethal dose (LD50) values range from 159-3919 mg/Kg, of which baicalein and quercetin are found to be mutagenic whereas butein is found to be the only immunotoxin. Molecular docking studies showed that the significant interaction (-7.5 to -8.3 kcal/mol) of the studied molecules in the binding pocket of the α-amylase protein relative to the control metformin with the crucial amino acids Asp 197, Glu 233, Asp 197, Glu 233, Trp 59, Tyr 62, His 101, Leu 162, Arg 195, His 299 and Leu 165. Chrysin was predicted to be a ligand with high absorption and lipophilicity with 84.6% absorption compared to metformin (78.3%). Moreover, quantum chemical, ADMET, drug-likeness and molecular docking profiles predicted that chrysin is a good bidentate ligand.

Preparation and in vitro/in vivo evaluation of a self-microemulsifying drug delivery system containing chrysin

OBJECTIVE

To prepare a self-microemulsifying drug delivery system (SMEDDS) to increase the solubility and oral bioavailability of chrysin.

METHODS

The preparation conditions were determined using factor analysis method. Preliminarily screening was conducted using compatibility tests and pseudo-ternary phase diagram studies. The central composite design-response surface methodology was used to determine the maximum drug loading and optimize SMEDDS formation, as characterized by surface morphology, pH, diameter, polydispersity index (PDI), zeta potential, and phase type. In vitro release of chrysin-suspension and chrysin-SMEDDS was investigated using the bulk-equilibrium reverse dialysis bag technique. Short-term stability of chrysin-SMEDDS at high and low temperatures was assessed. Pharmacokinetic behaviors were evaluated after intragastric and intravenous administration to rats.

RESULTS

The final optimal formulation was medium chain triglyceride:oleic acid:Cremophor RH40: Transcutol HP (w/w) (12%:12%:32%:44%), with a drug loading capacity of 5 mg/g. Diluted chrysin-SMEDDS was characterized as an oil-in-water type and spherical, with a diameter, pH, PDI, and zeta potential of 28.26 ± 0.83 nm, 5.60 ± 0.84, 0.18 ± 0.01, and -23.13 ± 0.95 mV, respectively. The release speed of chrysin-SMEDDS was significantly higher than that of chrysin-suspension, and the release process was not affected by the media pH. In vivo pharmacokinetic data revealed that the oral bioavailability of chrysin-SMEDDS was 2.7-fold higher than that of chrysin suspension, compared with the chrysin microemulsion.

CONCLUSION

The optimal SMEDDS formulation increased the dissolution and oral bioavailability of chrysin and may be useful for investigating chrysin efficacy in animal disease models and toxicokinetic studies.

Developing nutritional component chrysin as a therapeutic agent: Bioavailability and pharmacokinetics consideration, and ADME mechanisms

Chrysin is a promising naturally occurring flavonoid mainly found in honey and propolis. Although chrysin’s biological activities have been demonstrated and the mechanism of actions has been determined using in vitro and in vivo models, results from the current clinical studies were largely negative. A potential reason for chrysin’s low efficacy in humans is poor oral bioavailability. In this paper, we reviewed the preclinical and clinical pharmacokinetics studies of chrysin and analyzed the mechanism of poor in vivo efficacy with emphasis on its bioavailability and ADME mechanism. Low aqueous solubility, rapid metabolism mediated by UGTs and SULT, efficient excretion through efflux transporters including BCRP and MRP2 are the major reasons causing poor systemic bioavailability for chrysin. However, because of efficient enterohepatic recycling facilitated by phase II metabolism and efflux, chrysin’s bioavailability in the low GI tract is high. Thus, chrysin can be ideal for treating diseases in the terminal ileum and colon (e.g., carcinoma, local infection) since it is localized in the lower GI tract with limited delivery to other organs.

MPEG-PCL Nanomicelles Platform for Synergistic Metformin and Chrysin Delivery to Breast Cancer in Mice

BACKGROUND

Metformin (MET) is a well-known anti-diabetic drug that also has anti-cancer effects. However, high therapeutic doses of MET on cancer cells and the low efficacy of combinatory therapeutic approaches limit its clinical application. Recent studies have shown that chrysin (CHR) can improve the pharmaceutical efficacy of MET by suppressing human telomerase reverse transcriptase (hTERT) and cyclin D1 gene expression.

OBJECTIVE

This study aimed to develop different ratios of methoxy poly(ethylene glycol)-b-poly(e-caprolactone) (MPEG-PCL) micelles for breast cancer to co-deliver a synergistic CHR/MET combination.

METHODS

CHR/MET drug-loaded micelles were prepared by modified thin-film hydration. Fourier infrared spectrum, gel permeation chromatography, transmission electron microscopy, and high-performance liquid chromatography were used to evaluate the physicochemical properties of nanostructures. Cell proliferation and cell apoptosis were assessed by MTT and Annexin V-FITC/PI double staining method. The gene expression of hTERT and cyclin D1 was measured by real-time PCR assay. A subcutaneous mouse T47D xenograft model was established to evaluate the in vivo efficiency.

RESULTS

When the ratio of MPEG-PCL was 1:1.7, the highest drug loading rate and encapsulation efficiency of CHR (11.31±0.37) and MET (12.22±0.44) were observed. Uniform MPEG-PCL micelles of 51.70±1.91 nm allowed MET to incorporate with CHR, which were co-delivered to breast cancer cells. We demonstrated that CHR/MET co-delivery micelles showed a good synergistic effect on inhibiting proliferation in T47D cells (combination index=0.87) by suppressing hTERT and cyclin D1 gene expression. Compared with the free CHR/MET group, the apoptosis rate on T47D cells by CHR/MET nano-micelles significantly improved from 71.33% to 79.25%. The tumour volume and tumour weight of the CHR/MET group increased more slowly than that of the single-drug treatment group (P<0.05). Compared with the CHR/MET group, the tumour volume and tumour weight of the CHR/MET nano-micelle group decreased by 42% and 59%, respectively.

CONCLUSIONS

We demonstrated that ratiometric CHR/MET micelles could provide an effective technique for the treatment of breast cancer.

A critical review of spray-dried amorphous pharmaceuticals: Synthesis, analysis and application

New drugs are frequently found with poor water-solubility in recent pharmaceutical projects, which brings difficulties of bioavailability for the clinical development of new drugs. When these drug compounds in a crystalline state are absorbed by gastrointestinal tract, their dissolution rates and absorption rates are very limited. Nowadays, various methods have been developed to improve the solubility, dissolution and bioavailability of drugs. According to the characteristics of drugs, this work suggests the use of spray drying technology to amorphize APIs (active pharmaceutical ingredients) to improve their bioavailability. This work reviews the properties of the spray-dried amorphous drugs, the progress made in drug synthesis and application, and the existing problems.

Therapeutic Applications of Solid Dispersions for Drugs and New Molecules: In Vitro and In Vivo Activities

This review aims to provide an overview of studies that address the use, in therapeutic applications, of solid dispersions (SDs) with biological activities in vitro and/or in vivo mainly made up of polymeric matrices, as well as to evaluate the bioactive activity of their constituents. This bibliographic survey shows that the development of solid dispersions provides benefits in the physicochemical properties of bioactive compounds, which lead to an increase in their biological potential. However, despite the reports found on solid dispersions, there is still a need for biological assay-based studies, mainly in vivo, to assist in the investigation and to devise new applications. Therefore, studies based on such an approach are of great importance to enhance and extend the use of solid dispersions in the most diverse therapeutic applications.

Cyclodextrin Complexation Improves the Solubility and Caco-2 Permeability of Chrysin

Chrysin is a bioflavonoid that can be found in natural products such as honey and propolis, and it possesses several biological effects such as antioxidant, anti-inflammatory, and anti-cancer activity. However, it is poorly soluble in water, and its bioavailability is limited. The aim of this research is to investigate the chrysin solubilization capacity of different β-cylcodextrin derivatives and compare their biological activities. Chrysin was complexed with β-cyclodextrin (βCD), hydroxypropyl-β-, (HPBCD) sulfobutylether-β-, (SBECD), and randomly-methylated-β-cyclodextrin (RAMEB) by the lyophilization method in 1:1 and 1:2 molar ratios. The solubilities of the chrysin–cyclodextrin complexes were tested, and the solubilization abilities of cyclodextrins were studied by phase solubility experiments. The cytotoxicity of the complexes was measured by the MTT method, and the permeability enhancement was tested on Caco-2 monolayers. The solubility study showed that the complexes formed with RAMEB had the highest solubility in water. The phase solubility experiments confirmed the strongest interaction between RAMEB and chrysin. In the viability test, none of the complexes showed cytotoxicity up to 100 µM concentration. The permeability study revealed that both at 1:1 and 1:2 ratios, the RAMEB complexes were the most effective to enhance chrysin permeability through the Caco-2 monolayers. In conclusion, cyclodextrins, especially RAMEB, are suitable for improving chrysin solubility and absorption.