In Vitro Release and Bioavailability of Silybin from Micelle-Templated Porous Calcium Phosphate Microparticles

Preparation, Physical Characterization, Pharmacokinetics and Anti-Hyperglycemic Activity of Esculetin-Loaded Mixed Micelles

Despite its low water solubility, esculetin (EC) have been described to demonstrate various health benefits. Thus, we sought to develop esculetin-loaded mixed micelles (EC-M) delivery system to purposively improve biological availability and anti-hyperglycemia activity of EC. Thin-film hydration method was employed to fabricate EC-M, amid characterization with transmission electron microscopic analysis (TEM), coupled with physical properties such as particle size (PS), poly-dispersity index (PDI), zeta-potential (ZP) and stability testing. We analyzed in-vitro release and studied EC-M pharmacokinetics in rats. The hyperglycemic mice model was established with streptozotocin (STZ) to evaluate anti-hyperglycemic activity of EC-M. The PS, PDI and ZP of EC-M were 47.97 ± 0.41 nm, 0.189 ± 0.005 and -25.55 ± 0.28 mV, respectively. The release rate of EC-M increased comparable to free EC in the three media. The oral biological availability and half-life of EC-M increased respectively by 3.06 and 1.45 folds compared to free EC. Besides, we observed 46.21% decrease in blood glucose of mice in EC-M group comparable to the model control, wherein, the anti-hyperglycemic effect of EC-M was better compared to free EC. Conclusively, EC-M may ideally serve as a novel approach to enhance biological availability and increased anti-hyperglycemic activity of EC.

Porous biomaterials for tissue engineering: a review

The field of biomaterials has grown rapidly over the past decades. Within this field, porous biomaterials have played a remarkable role in: (i) enabling the manufacture of complex three-dimensional structures; (ii) recreating mechanical properties close to those of the host tissues; (iii) facilitating interconnected structures for the transport of macromolecules and cells; and (iv) behaving as biocompatible inserts, tailored to either interact or not with the host body. This review outlines a brief history of the development of biomaterials, before discussing current materials proposed for use as porous biomaterials and exploring the state-of-the-art in their manufacture. The wide clinical applications of these materials are extensively discussed, drawing on specific examples of how the porous features of such biomaterials impact their behaviours, as well as the advantages and challenges faced, for each class of the materials.

Fabrication and Preliminary In Vitro Evaluation of 3D-Printed Alginate Films with Cannabidiol (CBD) and Cannabigerol (CBG) Nanoparticles for Potential Wound-Healing Applications

In this study, drug carrier nanoparticles comprised of Pluronic-F127 and cannabidiol (CBD) or cannabigerol (CBG) were developed, and their wound healing action was studied. They were further incorporated in 3D printed films based on sodium alginate. The prepared films were characterized morphologically and physicochemically and used to evaluate the drug release profiles of the nanoparticles. Additional studies on their water loss rate, water retention capacity, and 3D-printing shape fidelity were performed. Nanoparticles were characterized physicochemically and for their drug loading performance. They were further assessed for their cytotoxicity (MTT Assay) and wound healing action (Cell Scratch Assay). The in vitro wound-healing study showed that the nanoparticles successfully enhanced wound healing in the first 6 h of application, but in the following 6 h they had an adverse effect. MTT assay studies revealed that in the first 24 h, a concentration of 0.1 mg/mL nanoparticles resulted in satisfactory cell viability, whereas CBG nanoparticles were safe even at 48 h. However, in higher concentrations and after a threshold of 24 h, the cell viability was significantly decreased. The results also presented mono-disperse nano-sized particles with diameters smaller than 200 nm with excellent release profiles and enhanced thermal stability. Their entrapment efficiency and drug loading properties were higher than 97%. The release profiles of the active pharmaceutical ingredients from the films revealed a complete release within 24 h. The fabricated 3D-printed films hold promise for wound healing applications; however, more studies are needed to further elucidate their mechanism of action.

A review of nanostructured delivery systems for the encapsulation, protection, and delivery of silymarin: An emerging nutraceutical

Silymarin exhibits biological activities that may promote human health and wellbeing, including antioxidant, antimicrobial, anti-inflammatory, and anti-cancer activities. Consequently, it has potential for application as a nutraceutical ingredient in functional foods and supplements. But its application for this purpose is currently limited by its poor water solubility, chemical stability, and bioavailability. The potential of nano-delivery systems to improve the functional performance of silymarin was reviewed in this manuscript. The formation, attributes, and applications of biopolymer-based, lipid-based, surfactant-based, and miscellaneous nanocarriers are discussed. In particular, the impact of the different delivery systems such as biopolymer-based, lipid-based delivery systems on the gastrointestinal fate of silymarin is summarized. The encapsulation in edible nanocarriers can improve the bioavailability of silymarin by enhancing its water-dispersibility, inhibiting its degradation, and increasing its absorption.These nanocarriers may therefore be utilized to incorporate this nutraceutical into functional foods and supplements in a bioavailable form.

Improved intestinal absorption and oral bioavailability of astaxanthin using poly (ethylene glycol)-graft-chitosan nanoparticles: preparation, in vitro evaluation, and pharmacokinetics in rats

BACKGROUND

Astaxanthin (ASTA) is a kind of food-derived active ingredient (FDAI) with antioxidant and antidiabetic functions. It is nontoxic but its poor solubility and low bioavailability hinder its application in the food industry. In this study, a novel carrier, polyethylene glycol-grafted chitosan (PEG-g-CS) was applied to enhance the bioavailability of astaxanthin. It encapsulated astaxanthin completely by solvent evaporation to manufacture astaxanthin using poly (ethylene glycol)-graft-chitosan nanoparticles (ASTA-PEG-g-CS) nanoparticles to improve absorption.

RESULTS

The ASTA-PEG-g-CS nanoparticles were spherical, with a particle size below 200 nm and a ζ potential of about -26 mV. Polyethylene glycol-grafted chitosan can encapsulate astaxanthin well, and the encapsulated astaxanthin was released rapidly - in 15 min in an in vitro release study. In a rat single-pass intestinal perfusion study, a low concentration of ASTA-PEG-g-CS nanoparticle (0.2 μg mL^-1 ) was better absorbed in the intestine. In particular, the jejunum could absorb most astaxanthin without a change in the concentration. An in vivo release study also demonstrated that ASTA-PEG-g-CS nanoparticles enhanced oral bioavailability significantly.

CONCLUSION

This novel carrier, PEG-g-CS, provided a simple way to encapsulate food, which improved the bioavailability of hydrophobic ingredients. © 2021 Society of Chemical Industry.

Systematic review of pharmacokinetics and potential pharmacokinetic interactions of flavonolignans from silymarin

Silymarin is an extract from the seeds (fruits) of Silybum marianum that contains flavonolignans and flavonoids. Although it is frequently used as a hepatoprotective agent, its application remains somewhat debatable, in particular, due to the low oral bioavailability of flavonolignans. Moreover, there are claims of its potential interactions with concomitantly used drugs. This review aims at a systematic summary and critical assessment of known information on the pharmacokinetics of particular silymarin flavonolignans. There are two known major reasons for poor systemic oral bioavailability of flavonolignans: (1) rapid conjugation in intestinal cells or the liver and (2) efflux of parent flavonolignans or formed conjugates back to the lumen of the gastrointestinal tract by intestinal cells and rapid excretion by the liver into the bile. The metabolism of phase I appears to play a minor role, in contrast to extensive conjugation and indeed the unconjugated flavonolignans reach low plasma levels after common doses. Only about 1%-5% of the administered dose is eliminated by the kidneys. Many in vitro studies tested the inhibitory potential of silymarin and its components toward different enzymes and transporters involved in the absorption, metabolism, and excretion of xenobiotics. In most cases, effective concentrations are too high to be relevant under real biological conditions. Most human studies showed no silymarin-drug interactions explainable by these suggested interferences. More interactions were found in animal studies, likely due to the much higher doses administered.

Improved oral bioavailability and anti-chronic renal failure activity of chrysophanol via mixed polymeric micelles

AIMS

This study was designed to prepare chrysophanol-loaded micelles (CLM) to improve the oral bioavailability, targetability and anti-chronic renal failure (CRF) activity of chrysophanol (CH).

METHODS

The preparation of CLM was achieved via thin-film dispersion technique. The in vitro release of CLM compared with free CH was measured in phosphate buffer solution (PBS) containing 0.5%w/v sodium dodecyl sulphate (pH 6.8) while the pharmacokinetic and anti-CRF activity study was also conducted in rats. Moreover, the tissue distribution of CLM was investigated in the mice.

RESULTS

The CLM had particle size (PS) of 29.64 ± 0.71 nm, and encapsulation efficiency (EE) of 90.48 ± 1.22%w/w. The cumulative release rate of CH from the micellar system was significantly higher than that of the free CH (86%m/m vs. 15%m/m, p < 0.01). In vivo pharmacokinetic studies showed that the bioavailability of CLM after oral administration was substantially improved (about 3.4 times) compared with free drugs (p < 0.01). Also, it was observed that CLM accumulated well in the liver and brain. Moreover, in vitro renal podocytes study showed that CLM had better protection against renal podocyte damage than the free CH. In addition, CLM significantly (p < 0.01) reduced levels of blood urea nitrogen (BUN), kidney injury molecule-1 (Kim-1), and serum creatinine (SCr), which obviously improved kidney damage in rats with CRF.

CONCLUSIONS

Collectively, these findings suggest that mixed micelles may be used as a promising drug delivery system for oral bioavailability improvement and concomitantly enhance the anti-CRF activity of CH, as well as provide a basis for the clinical application of CH.

Evaluation of Mogroside V as a Promising Carrier in Drug Delivery: Improving the Bioavailability and Liver Distribution of Silybin

The objective of this work was to investigate the capacity of mogroside V (MOG-V), a food additive, as a novel carrier to improve the bioavailability and liver distribution of silybin (SLY). Solid dispersion particles (SDPs) of SLY/MOG-V were prepared utilizing the solvent evaporation method. The physicochemical characterizations of SDPs were evaluated by using dynamic light scattering (DLS), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) measurements. DLS results demonstrated the formation of nanoparticles (206 nm) of SDPs in water. DSC and PXRD analysis revealed that SLY was in amorphous form or molecularly dispersed in SDPs. SDPs also exhibited a major increase in both dissolution rate and saturation solubility, as evidenced by a 1931-fold improvement (2201 μg/mL) in solubility compared with pure SLY (1.14 μg/mL). The pharmacokinetic study in rats showed that oral absorption of SLY/MOG-V SDPs was dramatically increased. The mean value of AUC until 12 h for SLY/MOG-V SDPs (27,481 ng·min/mL) was 24.5-fold higher than that of pure SLY (1122 ng·min/mL). In vivo tissue distribution experiment in mice confirmed that the major distribution tissue was changed from lungs to liver after SLY was loaded into MOG-V. In addition, even orally administrated to mice at a high dose (4.2 g/kg), MOG-V exhibited no undesirable effect on the plasma glucose concentrations. Thus, MOG-V may have the applicability to serve as an ideal excipient for solubilization or as a novel liver targeting carrier for the delivery of SLY.

Fabrication, characterization and optimization of berberine-loaded PLA nanoparticles using coaxial electrospray for sustained drug release

BACKGROUND

Berberine (BBR) broadly found in medicinal plants has a major application in pharmacological therapy as an anticancer drug. Clinical applications of this promising natural drug are limited due to its poor water solubility and low bioavailability.

OBJECTIVE

In this study, for the first time, we synthesized core-shell BBR-loaded PLA nanoparticles (NPBs) by using coaxial electrospray (CES) to solve the poor bioavailability of BBR.

METHODS

Three-factor (feeding rate, polymeric solution concentration and applied voltage), three-level, Box-Behnken design was used for optimization of the size and particle size distribution of the prepared NPBs.

RESULTS

Based on the results of response surface methodology, the NPBs with the mean size of 265 nm and particle size distribution of 43 nm were synthesized. A TEM image was used to well illustrate the core-shell structure of the NPBs. Encapsulation efficiency and BBR loading capacity for the optimized NPBs were determined at about 81% and 7.5%, respectively. Release of NPBs was examined at pH 7.4 and 5.8. NPBs had a slower release profile than free BBR in both pH values, and the rate of BBR release was more and faster in acidic pH than in physiological one. Effects of the NPBs on the drug release were confirmed by data fitting with six kinetic models. NPBs showed an increased cytotoxic efficacy against HCT116 cells (IC₅₀ = 56 μM), while NIH3T3 cells, non-neoplastic fibroblast cells, (IC₅₀ > 150 μM) were less affected by NPBs. Flow cytometry demonstrated that the cellular uptake of NPBs were higher than BBR at different concentrations.

CONCLUSIONS

A new approach was developed in this study to prepare NPBs using the CES process for improving the efficiency and controlled BBR release. It is concluded that nano-scaled NPBs prepared by CES can improve toxicity and chemotherapeutic properties of BBR against cancerous cells. We believe that these NPBs can exhibit further potential in cancer drug delivery systems. Graphical abstract.

A Valid Bisphosphonate Modified Calcium Phosphate-Based Gene Delivery System: Increased Stability and Enhanced Transfection Efficiency In Vitro and In Vivo

Calcium phosphate (CaP) nanoparticles, as a promising vehicle for gene delivery, have been widely used owing to their biocompatibility, biodegradability and adsorptive capacity for nucleic acids. Unfortunately, their utility in vivo has been profoundly restricted due to numerous technical barriers such as the lack of tissue specificity and limited transfection efficiency, as well as uncontrollable aggregation over time. To address these issues, an effective conjugate folate-polyethylene glycol-pamidronate (shortened as FA-PEG-Pam) was designed and coated on the surface of CaP/NLS/pDNA (CaP/NDs), forming a versatile gene carrier FA-PEG-Pam/CaP/NDs. Inclusion of FA-PEG-Pam significantly reduced the size of CaP nanoparticles, thus inhibiting the aggregation of CaP nanoparticles. FA-PEG-Pam/CaP/NDs showed better cellular uptake than mPEG-Pam/CaP/NDs, which could be attributed to the high-affinity interactions between FA and highly expressed FR. Meanwhile, FA-PEG-Pam/CaP/NDs had low cytotoxicity and desired effect on inducing apoptosis (71.1%). Furthermore, FA-PEG-Pam/CaP/NDs showed admirable transfection efficiency (63.5%) due to the presence of NLS peptides. What’s more, in vivo studies revealed that the hybrid nanoparticles had supreme antitumor activity (IR% = 58.7%) among the whole preparations. Altogether, FA-PEG-Pam/CaP/NDs was expected to be a hopeful strategy for gene delivery.

Bioavailability Enhancement of Poorly Soluble Drugs: The Holy Grail in Pharma Industry

Background:

Bioavailability, one of the prime pharmacokinetic properties of a drug, is defined as the fraction of an administered dose of unchanged drug that reaches the systemic circulation and is used to describe the systemic availability of a drug. Bioavailability assessment is imperative in order to demonstrate whether the drug attains the desirable systemic exposure for effective therapy. In recent years, bioavailability has become the subject of importance in drug discovery and development studies.

Methods:

A systematic literature review in the field of bioavailability and the approaches towards its enhancement have been comprehensively done, purely focusing upon recent papers. The data mining was performed using databases like PubMed, Science Direct and general Google searches and the collected data was exhaustively studied and summarized in a generalized manner.

Results:

The main prospect of this review was to generate a comprehensive one-stop summary of the numerous available approaches and their pharmaceutical applications in improving the stability concerns, physicochemical and mechanical properties of the poorly water-soluble drugs which directly or indirectly augment their bioavailability.

Conclusion:

The use of novel methods, including but not limited to, nano-based formulations, bio-enhancers, solid dispersions, lipid-and polymer-based formulations which provide a wide range of applications not only increases the solubility and permeability of the poorly bioavailable drugs but also improves their stability, and targeting efficacy. Although, these methods have drastically changed the pharmaceutical industry demand for the newer potential methods with better outcomes in the field of pharmaceutical science to formulate various dosage forms with adequate systemic availability and improved patient compliance, further research is required.

Formulation Strategies for Enhancing the Bioavailability of Silymarin: The State of the Art

Silymarin, a mixture of flavonolignan and flavonoid polyphenolic compounds extractable from milk thistle (Silybum marianum) seeds, has anti-oxidant, anti-inflammatory, anti-cancer and anti-viral activities potentially useful in the treatment of several liver disorders, such as chronic liver diseases, cirrhosis and hepatocellular carcinoma. Equally promising are the effects of silymarin in protecting the brain from the inflammatory and oxidative stress effects by which metabolic syndrome contributes to neurodegenerative diseases. However, although clinical trials have proved that silymarin is safe at high doses (>1500 mg/day) in humans, it suffers limiting factors such as low solubility in water (<50 μg/mL), low bioavailability and poor intestinal absorption. To improve its bioavailability and provide a prolonged silymarin release at the site of absorption, the use of nanotechnological strategies appears to be a promising method to potentiate the therapeutic action and promote sustained release of the active herbal extract. The purpose of this study is to review the different nanostructured systems available in literature as delivery strategies to improve the absorption and bioavailability of silymarin.

Preparation and Characterization of Syringic Acid-Loaded TPGS Liposome with Enhanced Oral Bioavailability and In Vivo Antioxidant Efficiency

In this study, syringic acid-loaded TPGS liposome (SA-TPGS-Ls) was successfully prepared to improve oral bioavailability of syringic acid (SA). SA is a natural and notable antioxidant activity compound with its limited bioavailability ascribable to its poor aqueous solubility and fast elimination. Recently, TPGS has become a perfect molecular biomaterial in developing several carrier systems with sustained, controlled, and targeted the drug delivery. SA-TPGS-Ls was prepared via thin-film dispersion method and characterized in terms of particle size, stability, morphology, and encapsulation efficiency (EE). The results showed that SA-TPGS-Ls had regular spherical-shaped nanoparticles with EE of 96.48 ± 0.76%. The pharmacokinetic studies demonstrated a delayed MRT and prolonged t_1/2, while relative oral bioavailability increased by 2.8 times. Tissue distribution showed that SA-TPGS-Ls maintained liver drug concentration while delayed elimination was also observed in the kidney. In CCl₄-induced hepatotoxicity study, the activities of hepatic T-AOC, GSH-Px, CAT, GSH, and SOD were greatly elevated, while serum biological markers ALT, AST, and AKP were reduced after treatment of mice with SA-TPGS-Ls. Histopathological studies confirmed that SA-TPGS-Ls could remarkably improve the status of hepatic tissues. Collectively, SA-TPGS-Ls significantly improved the drug encapsulation efficiency, stability coupled with bioavailability of SA, hence increasing in vivo antioxidant activity of the drug.

Mechanical Transformation of Compounds Leading to Physical, Chemical, and Biological Changes in Pharmaceutical Substances

This study demonstrates the link between the modification of the solid-phase pharmaceutical substances mechanical structure and their activity in waters with different molar ratio «deuterium-protium». Mechanochemical transformation of the powders of lactose monohydrate and sodium chloride as models of nutrients and components of dosage forms was investigated by the complex of physicochemical and biological methods. The solubility and kinetic activity of substances dispersed in various ways showed a positive correlation with the solvent isotope profile. Substances dissolved in heavy water were more active than solutes in natural water. Differential IR spectroscopy confirmed the modification of substituents in the sample of lactose monohydrate, demonstrating physicochemical changes during mechanical intervention. The biological activity of the compounds was determined by the method of Spirotox. The activation energy was determined by Arrhenius. Compared with the native compound, dispersed lactose monohydrate showed lower activation energy and, therefore, greater efficiency. In conclusion, proposed data confirm the statement that mechanical changes in compounds can lead to physicochemical changes that affect chemical and biological profiles.

Nanoencapsulation Improves Scavenging Capacity and Decreases Cytotoxicity of Silibinin and Pomegranate Oil Association

Silibinin (SB) and pomegranate oil (PO) present therapeutic potential due to antioxidant activity, but the biological performance of both bioactives is limited by their low aqueous solubility. To overcome this issue, the aim of the present investigation was to develop nanocapsule suspensions with PO as oil core for SB encapsulation, as well as assess their toxicity in vitro and radical scavenging activity. The nanocapsule suspensions were prepared by interfacial deposition of preformed polymer method. SB-loaded PO-based nanocapsules (SBNC) showed an average diameter of 157 ± 3 nm, homogenous size distribution, zeta potential of -14.1 ± 1.7 mV, pH of 5.6 ± 0.4 and SB content close to 100%. Similar results were obtained for the unloaded formulation (PONC). The nanocapsules controlled SB release at least 10 times as compared with free SB in methanolic solution. The SBNC scavenging capacity in vitro was statistically higher than free SB (p < 0.05). Cell viability in monocytes and lymphocytes was kept around 100% in the treatments with SBNC and PONC, while the SB and the PO caused a decrease around 30% at 50 μM (SB) and 724 μg/mL (PO). Protein carbonyls and DNA damage were minimized by SB and PO nanoencapsulation. Lipid peroxidation occurred in nanocapsule treatments regardless of the SB presence, which may be attributed to PO acting as substrate in reaction. The free compounds also caused lipid peroxidation. The results show that SBNC and PONC presented adequate physicochemical characteristics and low toxicity against human blood cells. Thereby, this novel nanocarrier may be a promising formulation for therapeutic applications.

Cancer chemoprevention through dietary flavonoids: what's limiting?

Flavonoids are polyphenols that are found in numerous edible plant species. Data obtained from preclinical and clinical studies suggest that specific flavonoids are chemo-preventive and cytotoxic against various cancers via a multitude of mechanisms. However, the clinical use of flavonoids is limited due to challenges associated with their effective use, including (1) the isolation and purification of flavonoids from their natural resources; (2) demonstration of the effects of flavonoids in reducing the risk of certain cancer, in tandem with the cost and time needed for epidemiological studies, and (3) numerous pharmacokinetic challenges (e.g., bioavailability, drug–drug interactions, and metabolic instability). Currently, numerous approaches are being used to surmount some of these challenges, thereby increasing the likelihood of flavonoids being used as chemo-preventive drugs in the clinic. In this review, we summarize the most important challenges and efforts that are being made to surmount these challenges.