Encapsulation of curcumin using supercritical antisolvent (SAS) technology to improve its stability and solubility in water

Formation and Characterization of Chitosan-Based Polyelectrolyte Complex Containing Antifungal Phenylpropanoids

In this work, a novel chitosan-based polyelectrolyte complex (PEC) was prepared using chitosan as the cationic polyelectrolyte, while a potassium salt of poly(maleic anhydride-alt-tetradecene) (PMA-14) served as the anionic counterpart. These PECs were used for the encapsulation of two nitroeugenol derivatives: 4-allyl-2-methoxy-6-nitrophenol (3) and 2-allyl-6-nitrophenol (4). The results confirm complex formation and efficient encapsulation of active compounds. Encapsulation efficiency (EE) was influenced by the chemical structure of the compounds, with 32.18% EE for 3 and 20.36% EE for 4. The resulting systems were characterized by fluorescence probing techniques, dynamic light scattering (DLS), and zeta potential. On the other hand, antifungal assays revealed that, in free form, 3 exhibits a much higher activity against Botritys cinerea than 4. However, no effect of encapsulation of both compounds on antifungal performance was observed. Results from molecular dynamic studies indicate that a stabilization effect is induced by compounds 3 and 4 during PEC formation, which is attributed to specific interactions between polyelectrolytes and guest molecules. These results are in line with the EE values measured for 3 and 4 and explain the low release from PECs of these molecules. Thus, the potential development of PEC-based systems for the delivery of bioactive compounds requires a deeper comprehension of parameters determining the relationship between encapsulation efficiency and delivery kinetics.

Curcumin - Bioavailability Enhancement by Prodrug Approach and Novel Formulations

Curcumin is a diverse natural pharmacological agent involved in various signal transduction mechanisms. Therapeutically, this potent molecule faces different challenges and issues related to low bioavailability due to its poor aqueous solubility, less permeability, faster elimination and clearance. Experts in synthetic chemistry and pharmaceuticals are continuously sparing their efforts to overcome these pharmacokinetic challenges by using different structural modification strategies and developing novel drug delivery systems. In this mini-review article, we are focusing on development of curcumin derivatives by different possible routes like conjugation with biomolecules, natural polymers, synthetic polymers, natural products, metal conjugates and co- administration with natural metabolic inhibitors. In addition to that, it was also focused on the preparation of modified formulations such as micelles, microemulsions, liposomes, complexes with phospholipids, micro and nanoemulsions, solid lipid nanoparticles, nano lipid carriers, biopolymer nanoparticles and microgels to improve the pharmacokinetic properties of the curcumin without altering its pharmacodynamics activity. This review helps to understand the problems associated with curcumin and different strategies to improve its pharmacokinetic profile.

Progress and Prospective of the Industrial Development and Applications of Eco-Friendly Colorants: An Insight into Environmental Impact and Sustainability Issues

Color is the prime feature directly associated with the consumer's attraction and choice of their food. The flavor, safety, and nutritional value of any food product are directly associated with the food color. Natural and synthetic colorants (dyes and pigments) have diversified applications in various sectors such as food, feed, pharmaceutical, textiles, cosmetics, and others. Concerning the food industry, different types of natural and synthetic colorants are available in the market. Synthetic food colorants have gained popularity as they are highly stable and cheaply available. Consumers worldwide prefer delightful foodstuffs but are more concerned about the safety of the food. After its disposal, the colloidal particles present in the synthetic colorants do not allow sunlight to penetrate aquatic bodies. This causes a foul smell and turbidity formation and gives a bad appearance. Furthermore, different studies carried out previously have presented the toxicological, carcinogenic effects, hypersensitivity reactions, and behavioral changes linked to the usage of synthetic colorants. Natural food colorings, however, have nutraceutical qualities that are valuable to human health such as curcumin extracted from turmeric and beta-carotene extracted from carrots. In addition, natural colorants have beneficial properties such as excellent antioxidant properties, antimutagenic, anti-inflammatory, antineoplastic, and antiarthritic effects. This review summarizes the sources of natural and synthetic colorants, their production rate, demand, extraction, and characterization of food colorants, their industrial applications, environmental impact, challenges in the sustainable utilization of natural colorants, and their prospects.

Supercritical CO2 versus water as an antisolvent in the crystallization process to enhance dissolution rate of curcumin

Antisolvent crystallization approach using either water (in conventional crystallization process (WAS)), or supercritical CO₂ (in supercritical anti-solvent crystallization (SCAS)), was employed in presence of hydroxypropyl methylcellulose (HPMC) to enhance the dissolution of curcumin. The impact of pressure, temperature and depressurization time on the SCAS process was studied using the Box-Behnken design to achieve the highest saturation solubility. A physical mixture of curcumin-HPMC was prepared for comparison purposes. Saturation solubility, scanning electron microscopy, differential scanning calorimetry, X-ray diffraction analysis and Fourier transform infrared spectroscopy were conducted to characterize the solid-state characteristics of the crystallized samples. Dissolution studies helped in ascertaining the effects of the crystallization techniques on the performance of the formulation. Curcumin crystalized by different antisolvent displayed varied shapes, sizes, saturation solubility's and dissolution properties. In SCAS process, the maximum saturation solubility (2.83 µg/mL) was obtained when the pressure, temperature and depressurization time were 275 bars, 55 °C, and 22 min respectively. The SCAS samples showed the highest dissolution (70%) in 30 min compared to WAS (27%), physical mixture (18%) and unprocessed curcumin (16%). The improved dissolution rate of SCAS sample originates from the development of sponge-like particles with augmented porosity, decreased crystallinity as well as increased solubility of curcumin.

Encapsulation of Bioactive Compounds for Food and Agricultural Applications

This review presents an updated scenario of findings and evolutions of encapsulation of bioactive compounds for food and agricultural applications. Many polymers have been reported as encapsulated agents, such as sodium alginate, gum Arabic, chitosan, cellulose and carboxymethylcellulose, pectin, Shellac, xanthan gum, zein, pullulan, maltodextrin, whey protein, galactomannan, modified starch, polycaprolactone, and sodium caseinate. The main encapsulation methods investigated in the study include both physical and chemical ones, such as freeze-drying, spray-drying, extrusion, coacervation, complexation, and supercritical anti-solvent drying. Consequently, in the food area, bioactive peptides, vitamins, essential oils, caffeine, plant extracts, fatty acids, flavonoids, carotenoids, and terpenes are the main compounds encapsulated. In the agricultural area, essential oils, lipids, phytotoxins, medicines, vaccines, hemoglobin, and microbial metabolites are the main compounds encapsulated. Most scientific investigations have one or more objectives, such as to improve the stability of formulated systems, increase the release time, retain and protect active properties, reduce lipid oxidation, maintain organoleptic properties, and present bioactivities even in extreme thermal, radiation, and pH conditions. Considering the increasing worldwide interest for biomolecules in modern and sustainable agriculture, encapsulation can be efficient for the formulation of biofungicides, biopesticides, bioherbicides, and biofertilizers. With this review, it is inferred that the current scenario indicates evolutions in the production methods by increasing the scales and the techno-economic feasibilities. The Technology Readiness Level (TRL) for most of the encapsulation methods is going beyond TRL 6, in which the knowledge gathered allows for having a functional prototype or a representative model of the encapsulation technologies presented in this review.

Microencapsulation of Natural Food Antimicrobials: Methods and Applications

The global demand for safe and healthy food with minimal synthetic preservatives is continuously increasing. Some natural food antimicrobials with strong antimicrobial activity and low toxicity have been considered as alternatives for current commercial food preservatives. Nonetheless, these natural food antimicrobials are hardly applied directly to food products due to issues such as food flavor or bioavailability. Recent advances in microencapsulation technology have the potential to provide stable systems for these natural antibacterials, which can then be used directly in food matrices. In this review, we focus on the application of encapsulated natural antimicrobial agents, such as essential oils, plant extracts, bacteriocins, etc., as potential food preservatives to extend the shelf-life of food products. The advantages and drawbacks of the mainly used encapsulation methods, such as molecular inclusion, spray drying, coacervation, emulsification, supercritical antisolvent precipitation and liposome and alginate microbeads, are discussed. Meanwhile, the main current applications of encapsulated antimicrobials in various food products, such as meat, dairy and cereal products for controlling microbial growth, are presented.

Assessment of Amentoflavone Loaded Sub-Micron Particle Preparation using Supercritical Antisolvent for its Antitumor Activity

Introduction:

The amentoflavone (AMF) loaded polymeric sub-micron particles were prepared using supercritical antisolvent (SAS) technology with the aim of improving the anticancer activity of AMF.

Materials and Methods:

Zein and phospholipid mixtures composed of Hydrogenated Phosphatidylcholine (HPC) and egg lecithin (EPC) were used as carrier materials and, the effects of carrier composition on the product morphology and drug release behavior were investigated. When the mass ratio of Zein/HPC/ EPC was 7/2/1, the AMF loaded particles were spherical shape and sub-micron sized around 400 nm, with a drug load of 4.3±0.3 w% and entrapment efficacy of 87.8±1.8%. The in vitro drug release assay showed that adding EPC in the wall materials could improve the dispersion stability of the released AMF in an aqueous medium, and the introduction of HPC could accelerate the drug release speed.

Results:

MTT assay demonstrated that AMF-loaded micron particles have an improved inhibitory effect on A375 cells, whose IC50 was 37.39μg/ml, compared with that of free AMF(130.2μg/ml).

Conclusion:

It proved that the AMF loaded sub-micron particles prepared by SAS were a prospective strategy to improve the antitumor activity of AMF, and possibly promote the clinical use of AMF preparations.

Essential Oil Nanoemulsion as Eco-Friendly and Safe Preservative: Bioefficacy Against Microbial Food Deterioration and Toxin Secretion, Mode of Action, and Future Opportunities

Microbes are the biggest shareholder for the quantitative and qualitative deterioration of food commodities at different stages of production, transportation, and storage, along with the secretion of toxic secondary metabolites. Indiscriminate application of synthetic preservatives may develop resistance in microbial strains and associated complications in human health with broad-spectrum environmental non-sustainability. The application of essential oils (EOs) as a natural antimicrobial and their efficacy for the preservation of foods has been of present interest and growing consumer demand in the current generation. However, the loss in bioactivity of EOs from fluctuating environmental conditions is a major limitation during their practical application, which could be overcome by encapsulating them in a suitable biodegradable and biocompatible polymer matrix with enhancement to their efficacy and stability. Among different nanoencapsulated systems, nanoemulsions effectively contribute to the practical applications of EOs by expanding their dispersibility and foster their controlled delivery in food systems. In line with the above background, this review aims to present the practical application of nanoemulsions (a) by addressing their direct and indirect (EO nanoemulsion coating leading to active packaging) consistent support in a real food system, (b) biochemical actions related to antimicrobial mechanisms, (c) effectiveness of nanoemulsion as bio-nanosensor with large scale practical applicability, (d) critical evaluation of toxicity, safety, and regulatory issues, and (e) market demand of nanoemulsion in pharmaceuticals and nutraceuticals along with the current challenges and future opportunities.

Effect of the Carrier on the Coprecipitation of Curcumin through Supercritical-Assisted Atomization

In this paper, composite systems containing curcumin (CUR) were prepared through supercritical-assisted atomization (SAA), using different carriers. Curcumin is particularly interesting in the pharmaceutical and nutraceutical fields for its antioxidant, antitumoral, and anti-inflammatory properties. However, its therapeutic effect on human health is restricted by its poor water solubility and low dissolution rate, limiting its absorption after its oral administration. To increase the dissolution rate and then the bioavailability of the active compound, CUR was coprecipitated with polymeric, i.e., polyvinylpyrrolidone (PVP) and dextran (DXT), and not polymeric, i.e., hydroxypropyl-β-cyclodextrin (HP-β-CD), carriers. The effects of some operating parameters, namely the concentration of solutes in solution and the active compound/carrier ratio, on the morphology and the particle size distribution of the powders were investigated. Submicrometric particles were produced with all the carriers. Under the best operating conditions, the mean diameters ± standard deviation were equal to 0.69 ± 0.20 μm, 0.40 ± 0.13 μm, and 0.81 ± 0.25 μm for PVP/CUR, DXT/CUR, and HP-β-CD/CUR, respectively. CUR dissolution rates from coprecipitated particles were significantly increased in the case of all the carriers. Therefore, the results are exciting from a pharmaceutical and nutraceutical point of view, to produce supplements containing curcumin, but assuring a high dissolution rate and bioavailability and, consequently, a more effective therapeutic effect.

Introducing nano/microencapsulated bioactive ingredients for extending the shelf-life of food products

The shelf-life of foods is affected by several aspects, mainly chemical and microbial events, resulting in a considerable decline in consumer's acceptance. There is an increasing interest to substitute synthetic preservatives with the plant-based bioactive ingredients which are safe and natural. However, full implementation of this replacement is postponed by some challenges associated with bioactive ingredients, including their low chemical stability, off-flavor, low solubility, and short-term effectiveness. Encapsulation could overcome these limitations. The present review explains current trends in applying natural encapsulated ingredients for food preservation based on a classified description including essential oils, plant extracts, phenolics, carotenoids, etc. and their application for extending food shelf-life mostly dealing with antimicrobial, ant-browning and antioxidant properties. Encapsulation techniques, especially nanoencapsulation, is a promising strategy to overcome their limitations. Moreover, better results are obtained using a combination of proteins and polysaccharides as wall materials than single polymers. The encapsulation method and type of encapsulants highly influences the releasing mechanism and physicochemical properties of bioactive ingredients. These factors together with optimizing the conditions of encapsulation process leads to a cost-effective and well encapsulated ingredient which is more efficient than its free form in shelf-life improvement. It has been shown that the well-designed encapsulation systems, finally, boost the shelf-life-promoting functions of the bioactive ingredients, mostly due to enhancing their solubility, homogeneity in food matrices and contact surface with deteriorative agents, and providing their prolonged presence over food storage and processing via increasing the thermal and processing stability of bioactive compounds, as well as controlling their release on food surfaces, or/and within food packages. To this end and given the numerous wall and bioactive core substances available, further studies are needed to evaluate the efficiency of many encapsulated forms of both conventional and novel bioactive ingredients in food shelf-life extending since the interactions and anti-spoiling behaviors of the ingredients in various encapsulation systems and foodstuffs are highly variable that should be optimized and characterized before any industrial application.

Developmental Strategies of Curcumin Solid Dispersions for Enhancing Bioavailability

BACKGROUND

Although curcumin has been demonstrated to be beneficial in treating various diseases, its low solubility, chemical stability and bioavailability limit its application, especially in cancer therapy.

METHODS

Solid dispersions have been utilized in the last few decades to improve the bioavailability and stability of curcumin.

RESULTS

However, there is a lack of summaries and classifications of the methods for preparing curcumin with this technology. The current review aims to overview the strategies used to develop solid dispersions containing curcumin for improving drug delivery. The classification of techniques for creating solid dispersions for curcumin was summarized, including systems for protecting curcumin degradation despite its chemical stability. The applications of advanced nanotechnologies in recent studies of solid dispersions were also discussed to explain the roles of nanoparticles in formulations.

CONCLUSION

This overview of recent developments in formulating solid dispersions for improving curcumin bioavailability will contribute to future studies of curcumin for clinical development.

Supercritical fluid technology for solubilization of poorly water soluble drugs via micro- and naonosized particle generation

Approximately two-third of the compounds in the pharmaceutical industry were developed through combinatorial chemistry and high throughput screening of particulate solids. Poor solubility and bioavailability of these pharmaceuticals are challenging attributes confronted by a formulator during product development. Hence, substantial efforts have been directed into the research on particle generation techniques. Although the conventional methods, such as crushing or milling and crystallization or precipitation, are still used; supercritical fluid technology introduced in the mid-1980s presents a new method of particle generation. Supercritical fluid processes not only produce micro- and nanoparticles with a narrow size distribution, they are also employed for the microencapsulation, cocrystallization, and surface coating with polymer. Recognized as a green technology, it has emerged as successful variants chiefly as Rapid Expansion of supercritical solutions (RESS), Supercritical anti-solvent (SAS) and Particles from Gas Saturated Solution (PGSS) depending upon type of solvent, solute, antisolvent and nebulization techniques. Being economical and eco-friendly, supercritical fluid technolgy has garnered considerable interest both in academia and industry for modification of physicochemical properties such as particle size, shape, density and ultimately solubility. The current manuscript is a comprehensive update on different supercritical fluid processes used for particle generation with the purpose of solubility enhancement of drugs and hence bioavailability.

Trends on the Rapid Expansion of Supercritical Solutions Process Applied to Food and Non-food Industries

BACKGROUND

The supercritical fluids applied to particle engineering over the last years have received growing interest from the food and non-food industries, in terms of processing, packaging, and preservation of several products. The rapid expansion of supercritical solutions (RESS) process has been recently reported as an efficient technique for the production of free-solvent particles with controlled morphology and size distribution.

OBJECTIVE

In this review, we report technological aspects of the application of the RESS process applied to the food and non-food industry, considering recent data and patent survey registered in literature.

METHODS

The effect of process parameters cosolvent addition, temperature, pressure, nozzle size among others, during RESS on the size, structure and morphology of the resulted particles, and the main differences about recent patented RESS processes are reviewed.

RESULTS

Most of the experimental works intend to optimize their processes through investigation of process parameters.

CONCLUSION

RESS is a feasible alternative for the production of particles with a high yield of bioactive constituents of interest to the food industry. On the other hand, patents developed using this type of process for food products are very scarce, less attention being given to the potential of this technique to develop particles from plant extracts with bioactive substances.

Interaction of carbon nanotubes with curcumin: Effect of temperature and pH on simultaneous static and dynamic fluorescence quenching of curcumin using carbon nanotubes

Curcumin (Cur) has medicinal properties, undergoes hydrolysis, and has low water solubility that limits its bioavailability and industrial usage. Different host molecules such as carbon nanotubes (CNT) can be useful in improving solubility and stabilizing Cur, therefore understanding the interaction of Cur with host molecules such as CNT is crucial. In this study, UV-visible light absorption and fluorescence spectroscopic techniques have been applied to reveal the interaction of Cur with CNT. Visible light absorption of Cur increases with CNT concentration, whereas fluorescence intensity of Cur is quenched in the presence of CNT. The obtained results confirm that fluorescence reduction is due to both static and dynamic quenching and is a result of the ground state and excited-state complex formation. The pH environment influences the quenching rate due to deprotonation of Cur at higher pH; excess OH- ion concentration in the solution further discourages electrostatic interaction between the deprotonated form of Cur with CNT. It is found that at lower temperatures (<35°C) dynamic quenching is much more dominant and at higher temperatures (45°C) static quenching is more dominant. The interaction is further supported using X-ray diffraction patterns and Fourier transform infrared spectra in the solid state, and suggests encapsulation of curcumin within the CNT. It is further evident that fluorescence quenching of Cur using CNT is further enhanced in the presence of several salts, as increase in ionic strength of the solution pushes the hydrophobic Cur molecule towards the CNT core by increasing the proximity between them.