Cyclodextrins as an encapsulation molecular strategy for volatile organic compounds – pharmaceutical applications

The Characterization and Antioxidant and Erythroprotective Effects of β-Carotene Complexed in β-Cyclodextrin

β-carotene (β-C) is a hydrophobic compound, easily degradable by light and oxygen and with low solubility, limiting its applications. β-cyclodextrin (β-CD) can encapsulate β-C, protecting it from degradation and maintaining its bioactivity. Therefore, this research aimed to characterize and determine the antioxidant and erythroprotective activity of β-C/β-CD inclusion complexes. The co-precipitation technique was used to elaborate β-C/β-CD in a 40:60 ratio, obtaining a high yield (94.10%), an entrapment efficiency of 82.47%, and a loading efficiency of 11.92%. The moisture of β-C/β-CD was 2.93%. β-C release increased over the time of 216 h (80.8%, 92.8%, and 97.4% at 8 °C, 25 °C, and 37 °C, respectively). A UV-visible analysis confirmed the presence of β-carotene in the inclusion complex, indicating successful encapsulation without significant structural changes. According to the adsorption-desorption isotherms, the complexes showed a type II isotherm. The FT-IR and Raman spectroscopy confirmed the formation of the inclusion complex, which interacted by hydrogen bonds, hydrophobic interactions, or van der Waals forces. The DSC showed an endothermic peak at 118 °C in the β-C/β:CD. The TGA revealed reduced water loss in the β-carotene/β-cyclodextrin complex, indicating limited water binding due to encapsulation. The microscopic surface morphologies observed by the SEM of β-C/β-CD were irregular-shaped clumps in the surface with a particle average size of 8.09 µm. The X-ray diffraction showed a crystalline structure of the complex. The zeta potential determination indicated a negative charge (-23 and -32 mV). The ABTS, DPPH, and FRAP demonstrated the antioxidant activity of β-C/β:CD (34.09%, 21.73%, and 8.85. mM ET/g, respectively), similar to pure β-C (34.64%, 22.63%, and 9.12 μM ET/g, respectively). The complexes showed an erythroprotective effect inhibiting hemolysis (64.09%). Therefore, with these characteristics, β-CD is a good encapsulant for β-C, and this complex could be applied in the food and pharmaceutical industries.

Advances in plant essential oils and drug delivery systems for skincare

Background

Essential oils, often referred to as "liquid gold," are renowned for their broad biological activity. Ancient Egyptians used essential oils' antibacterial and antiseptic effects to preserve mummies, ancient Greeks used olive oil for sun protection, and ancient Chinese used essential oils to treat wounds. When essential oils are applied to the facial skin, their potent anti-inflammatory, antioxidant, and antibacterial pharmacological characteristics provide various benefits, including sunscreen, skin-whitening, and anti-aging effects.

Purpose

This paper aims to summarize the application of plant essential oil in skin whitening, anti-inflammatory, antioxidant and antibacterial in recent years, and deeply analyzes the internal relationship between essential oil and modern drug delivery system, expounds how to overcome the limitations of essential oil through specific drug delivery system, to enhance its biological activity and stability, realize sustained release and reduce its potential toxicity, and also discusses the positive effects of essential oil on brain function through olfactory pathway, emphasizes the possible safety risks in the use of essential oil, and puts forward corresponding suggestions for use.

Methods

Using keywords such as "essential oils," "antioxidant," "anti-tyrosinase," Antibacterial Effects and anti-inflammatory," "anti-anxiety," and "drug carrier delivery systems," a comprehensive search was conducted in the PubMed, CNKI, Baidu, and Wanfang databases to summarize articles from the past 5 years. Further screening was performed to select studies demonstrating the efficacy of essential oils through topical or external application.

Results

Various essential oils showed their efficacy as strong oxidants, antibacterial agents, anti-inflammatory agents, and skin-whitening agents. Combined with a new drug delivery system, it not only enhances the biological activity of essential oil but also reduces the inherent defects of essential oil, such as volatility, irritation, and toxicity, and has a targeted delivery effect. At the same time, the integration of essential oil into skin care products can make use of the dual functions of smell and the epidermal system to nourish and repair the skin and maximize the pharmacological effects of essential oil.

Conclusion

This review delves into the application of essential oils and delivery systems, advocating for a broader integration of natural plant resources with modern technology. By strategically utilizing essential oils, we can promote the sustainable development of the global economy. However, extensive clinical trials are still required to evaluate the effectiveness and safety of essential oil delivery systems.

Preparation, characterization, oral bioavailability, and pharmacodynamic study of eugenol-porous silica solidified powder

Eugenol possesses anti-inflammatory and antioxidant properties, and may serve as a potential therapeutic agent for hepatic fibrosis. However, the development of solid eugenol formulations is challenging due to its volatility. To address this issue, this study employed porous silica to adsorb solidified eugenol. The solidified powder was characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). In addition, the differences in in vitro release and oral bioavailability between eugenol and solidified eugenol powder were investigated. The effectiveness of eugenol and eugenol powder in treating liver fibrosis was investigated using enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), and histopathological observations. Our results indicate that porous silica can effectively solidify eugenol into powder at a lower dosage. Furthermore, we observed that porous silica accelerates eugenol release in vitro and in vivo. The pharmacodynamic results indicated that eugenol has a positive therapeutic effect against hepatic fibrosis and that porous silica does not affect its efficacy. In conclusion, porous silica was able to solidify eugenol, which may facilitate the preparation and storage of solid formulations.

Enhancing orofacial pain relief: α-phellandrene complexed with hydroxypropyl-β-cyclodextrin mitigates orofacial nociception in rodents

Orofacial pain affects 10-15% of adults and can severely impact quality of life. Despite ongoing treatment challenges, monoterpene alpha-phellandrene (PHE) shows potential therapeutic benefits. This study aimed to develop and evaluate an inclusion complex of PHE with hydroxypropyl-beta-cyclodextrin (PHE-HPβCD) for treating orofacial pain. The PHE-HPβCD complex was created using physical mixing and characterized by differential scanning calorimetry (DSC) and high-performance liquid chromatography (HPLC) to determine encapsulation efficiency. The complex exhibited a 70.45% encapsulation efficiency. Male Swiss mice were used in models of orofacial pain induced by formalin, cinnamaldehyde, glutamate, and corneal nociception by hypertonic saline. Additionally, cytokine levels (TNF-α and IL-1β) were measured in the upper lip tissue of mice subjected to the formalin model. Both PHE and PHE-HPβCD showed significant antinociceptive effects at a 50 mg/kg dose during formalin-induced pain, reducing both neurogenic and inflammatory phases of pain. PHE-HPβCD also reduced TNF-α and IL-1β levels. For cinnamaldehyde and glutamate-induced nociception, both treatments reduced pain behavior, but only PHE-HPβCD decreased eye wipes in corneal nociception. These results suggest that PHE, especially in complexed form, alleviates orofacial pain by potentially modulating pain-related receptors (TRPA1 and TRPV1), mediators, like glutamate, and reducing pro-inflammatory cytokines. Further research is needed to explore the precise mechanisms of PHE in chronic orofacial pain models, but the study indicates promising avenues for new pain treatments.

Guest inclusion by native cyclodextrins in solid state and solutions: A review

In many industrial applications, preparation of cyclodextrin (CD) inclusion complexes with drugs, food additives, dyes and components of essence oils is performed in solid mixtures, slurries or paste-like systems having lack of water to dissolve cyclodextrin and guest completely. Such systems need a different description than supplied by classical analysis of CD complexation in aqueous solutions. The main feature of solid-state guest inclusion is the phase transition from solid CD to solid inclusion compound. This implies a complex interplay between a size exclusion effect for guest inclusion, a cooperative activation of this process by the third component such as water or organic compound and competition of guest and water for the space inside CD crystal lattice. The present review summarizes the current state of research of guest inclusion by native CDs in solid state and compares the driving forces of this process and its structure-property relationships with those of complexation in aqueous solutions. For an adequate comparison, the latter process was analyzed in thermodynamic activity scale, which allowed to separate hydrophobic effect and such important factors of complex stability as guest molecular shape and "high-energy" water.

Microencapsulation techniques for developing cannabidiol formulations: a review

Cannabidiol (CBD), extracted from Cannabis sativa L., holds therapeutic promise without inducing psychoactive effects seen with Δ9-tetrahydrocannabinol. Its interaction with the endocannabinoid system plays a pivotal role in regulating mood, pain perception and immune function. Nevertheless, CBD encounters hurdles in clinical application due to its poor bioavailability and water solubility. To overcome these limitations, researchers are exploring microencapsulation techniques, which involve encapsulating CBD within protective matrices. This comprehensive review offers insights into various microencapsulation methods for CBD, scrutinizing their advantages, limitations and implications for formulation optimization. By elucidating the potential of microencapsulation, this review underscores its promise in refining CBD therapy and addressing challenges associated with administration.

Optimizing Antitumor Effect of Triple-Negative Breast Cancer via Rosmarinic Acid-β-Cyclodextrin Inclusion Complex

Background: Rosmarinic acid (ROS) has gained notable attention for its anticancer potential; however, its limited aqueous solubility hinders its effective delivery and application in pharmaceutical formulations. Methods: To overcome this limitation, an inclusion complex of ROS with β-cyclodextrin (β-CD) was prepared using the recrystallization method. The resultant ROS-β-CD complex was comprehensively characterized by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Results: The ROS-β-CD complex showed a significant improvement in the solubility and dissolution profile of ROS, underscoring its potential for enhanced bioavailability and therapeutic efficacy in pharmaceutical applications. In vitro assays were performed to assess the effects on cell viability, proliferation, apoptotic pathways, and 3D spheroid tumor models. Conclusions: The results demonstrated that ROS-β-CD exhibited superior anticancer properties compared to free ROS, effectively reducing the viability and proliferation of the MD-MBA-231 cell line and inducing apoptosis. This research signifies a substantial advancement in developing therapeutic strategies for TNBC, leveraging the distinct properties of the ROS-β-CD inclusion complex.

Cyclodextrin Complexes for the Treatment of Chagas Disease: A Literature Review

Cyclodextrins are ring-shaped sugars used as additives in medications to improve solubility, stability, and sensory characteristics. Despite being widespread, Chagas disease is neglected because of the limitations of available medications. This study aims to review the compounds used in the formation of inclusion complexes for the treatment of Chagas disease, analyzing the incorporated compounds and advancements in related studies. The databases consulted include Scielo, Scopus, ScienceDirect, PubMed, LILACS, and Embase. The keywords used were "cyclodextrin AND Chagas AND disease" and "cyclodextrin complex against Trypanosoma cruzi". Additionally, a statistical analysis of studies on Chagas disease over the last five years was conducted, highlighting the importance of research in this area. This review focused on articles that emphasize how cyclodextrins can improve the bioavailability, therapeutic action, toxicity, and solubility of medications. Initially, 380 articles were identified with the keyword "cyclodextrin AND Chagas disease"; 356 were excluded for not being directly related to the topic, using the keyword "cyclodextrin complex against Trypanosoma cruzi". Over the last five years, a total of 13,075 studies on Chagas disease treatment were found in our literature analysis. The studies also showed interest in molecules derived from natural products and vegetable oils. Research on cyclodextrins, particularly in the context of Chagas disease treatment, has advanced significantly, with studies highlighting the efficacy of molecules in cyclodextrin complexes and indicating promising advances in disease treatment.

Study of the Enantioselectivity and Recognition Mechanism of Allyl-β-CD Modified Organic Polymer Monolithic Capillary Column

Allyl-β-CD was synthesized and used as the chiral functional monomer to prepare chiral organic polymer monolithic columns in capillary HPLC. First, the enantioselectivity of the prepared allyl-β-CD modified organic polymer monolithic capillary columns was investigated. Then, the influences of enantioseparation conditions of chiral drugs were further explored. Finally, the recognition mechanism was studied by molecular docking with AutoDock. Complete enantioseparations of four chiral drugs as well as partial enantioseparations of eight chiral drugs have been achieved. Results showed that the RSD values for run-to-run, day-to-day, and column-to-column variations ranged from 1.2% to 4.6%, 1.4% to 4.7%, and 2.0% to 6.1%, respectively. The enantioselectivity factor rather than resolution is correlated with the binding free energy difference between enantiomers with allyl-β-CD. Furthermore, the abundant ether bonds, hydroxyl groups, and hydrophobic cavities in cyclodextrin are responsible for the enantioseparation ability of the chiral monolithic capillary columns.

A comparative study on the preparation and evaluation of solubilizing systems for silymarin

Silymarin (SM) exhibits clinical efficacy in treating liver injuries, cirrhosis, and chronic hepatitis. However, its limited water solubility and low bioavailability hinder its therapeutic potential. The primary objective of this study was to compare the in vitro and in vivo characteristics of the four distinct SM solubilization systems, namely SM solid dispersion (SM-SD), SM phospholipid complex (SM-PC), SM sulfobutyl ether-β-cyclodextrin inclusion complex (SM-SBE-β-CDIC) and SM self-microemulsifying drug delivery system (SM-SMEDDS) to provide further insights into their potential for enhancing the solubility and bioavailability of SM. The formation of SM-SD, SM-PC, and SM-SBE-β-CDIC was thoroughly characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and powder X-ray diffractometry (PXRD) techniques to analyze the changes in their microscopic structure, molecular structure, and crystalline state. The particle size and polydispersity index (PDI) of SM-SMEDDS were 71.6 ± 1.57 nm, and 0.13 ± 0.03, respectively. The self-emulsifying time of SM-SMEDDS was 3.0 ± 0.3 min. SM-SMEDDS exhibited an improved in vitro dissolution rate and demonstrated the highest relative bioavailability compared to pure SM, SM-SD, SM-PC, SM-SBE-β-CDIC, and Legalon®. Consequently, SMEDDS shows promise as a drug delivery system for orally administered SM, offering enhanced solubility and bioavailability.

Encapsulation of phenolic acids within food-grade carriers systems: a systematic review

Phenolic acids are natural compounds with potential therapeutic effects against various diseases. However, their incorporation into food and pharmaceutical products is limited by challenges such as instability, low solubility, and reduced bioavailability. This systematic review summarizes recent advances in phenolic acid encapsulation using food-grade carrier systems, focusing on proteins, lipids, and polysaccharides. Encapsulation efficiency, release behavior, and bioavailability are examined, as well as the potential health benefits of encapsulated phenolic acids in food products. Strategies to address limitations of current encapsulation systems are also proposed. Encapsulation has emerged as a promising method to enhance the stability and bioavailability of phenolic acids in food products, and various encapsulation technologies have been developed for this purpose. The use of proteins, lipids, and carbohydrates as carriers in food-grade encapsulation systems remains a common approach, but it is associated with certain limitations. Future research on phenolic acid encapsulation should focus on developing environmentally friendly, organic solvent-free, low-energy, scalable, and stable encapsulation systems, as well as co-encapsulation methods that combine multiple phenolic acids or phenolic acids with other bioactive substances to produce synergistic effects.

Advancements in application of chitosan and cyclodextrins in biomedicine and pharmaceutics: recent progress and future trends

The global community is faced with numerous health concerns such as cancer, cardiovascular and neurological diseases, diabetes, joint pain, osteoporosis, among others. With the advancement of research in the fields of materials chemistry and medicine, pharmaceutical technology and biomedical analysis have entered a new stage of development. The utilization of natural oligosaccharides and polysaccharides in pharmaceutical/biomedical studies has gained significant attention. Over the past decade, several studies have shown that chitosan and cyclodextrin have promising biomedical implications in background analysis, ongoing development, and critical applications in biomedical and pharmaceutical research fields. This review introduces different types of saccharides/natural biopolymers such as chitosan and cyclodextrin and discusses their wide-ranging applications in the biomedical/pharmaceutical research area. Recent research advances in pharmaceutics and drug delivery based on cyclodextrin, and their response to smart stimuli, as well as the biological functions of cyclodextrin and chitosan, such as the immunomodulatory effects, antioxidant, and antibacterial properties, have also been discussed, along with their applications in tissue engineering, wound dressing, and drug delivery systems. Finally, the innovative applications of chitosan and cyclodextrin in the pharmaceutical/biomedicine were reviewed, and current challenges, research/technological gaps, and future development opportunities were surveyed.

Microencapsulation for Pharmaceutical Applications: A Review

In order to improve bioavailability, stability, control release, and target delivery of active pharmaceutical ingredients (APIs), as well as to mask their bitter taste, to increase their efficacy, and to minimize their side effects, a variety of microencapsulation (including nanoencapsulation, particle size <100 nm) technologies have been widely used in the pharmaceutical industry. Commonly used microencapsulation technologies are emulsion, coacervation, extrusion, spray drying, freeze-drying, molecular inclusion, microbubbles and microsponge, fluidized bed coating, supercritical fluid encapsulation, electro spinning/spray, and polymerization. In this review, APIs are categorized by their molecular complexity: small APIs (compounds with low molecular weight, like Aspirin, Ibuprofen, and Cannabidiol), medium APIs (compounds with medium molecular weight like insulin, peptides, and nucleic acids), and living microorganisms (such as probiotics, bacteria, and bacteriophages). This article provides an overview of these microencapsulation technologies including their processes, matrix, and their recent applications in microencapsulation of APIs. Furthermore, the advantages and disadvantages of these common microencapsulation technologies in terms of improving the efficacy of APIs for pharmaceutical treatments are comprehensively analyzed. The objective is to summarize the most recent progresses on microencapsulation of APIs for enhancing their bioavailability, control release, target delivery, masking their bitter taste and stability, and thus increasing their efficacy and minimizing their side effects. At the end, future perspectives on microencapsulation for pharmaceutical applications are highlighted.

New insights into the influence of encapsulation materials on the feasibility of ultrasonic-assisted encapsulation of Mosla chinensis essential oil

The study aimed to estimate the feasibility of α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), and γ-cyclodextrin (γ-CD) to encapsulate Mosla chinensis essential oil (EO) by ultrasonic-assisted method. The physical properties variations, stabilization mechanisms, and formation processes of the inclusion complexes (ICs) were investigated using experimental methods, molecular docking, and molecular dynamics (MD) simulation. Scanning electron microscopy, fourier transform infrared spectroscopy, thermogravimetric analysis, and gas chromatography-mass spectrometry showed that the ICs were successfully prepared, which differentially improved the thermal stability and retained the chemical composition of EO. The dissolution profile showed that the Peppas model can be used to describe the diffuse release mechanism of EO. Finally, molecular docking and MD simulation theoretically confirmed the interaction and conformational changes of carvacrol (the main active component of Mosla chinensis EO) inside the cavity of CDs. The results indicate that hydrogen bonding was the primary driving force for the carvacrol spontaneous access to the cavity. Further, a binding dynamic balance occurs between carvacrol and β-CD, whereas a bind and away dynamic balance occurs in the IC between carvacrol and α-CD, γ-CD. The comprehensive results show that the medium cavity size of β-CD is a suitable host molecule for Mosla chinensis EO of encapsulation, release, and stabilization. A combination of experimental and theoretical calculations is useful for the pinpoint targeted design and optimization of CD molecular encapsulation of small entity molecules. β-CD was rationally screened as a better candidate for stabilizing EO, which provides an option for a meaningful path to realistic EO applications.

Molecular dynamics simulation techniques and their application to aroma compounds/cyclodextrin inclusion complexes: A review

Homeostatic technologies play a crucial role in maintaining the quality and extending the service life of aroma compounds (ACs). Commercial cyclodextrins (CDs) are commonly used to form inclusion complexes (ICs) with ACs to enhance their solubility, stability, and morphology. The selection of suitable CDs and ACs is of paramount importance in this process. Molecular dynamics (MD) simulations provide an in-depth understanding of the interactions between ACs and CDs, aiding researchers in optimising the properties and effects of ICs. This review offers a systematic discussion of the application of MD simulations in ACs/CDs ICs, covering the establishment of the simulation process, parameter selection, model evaluation, and various application cases, along with their advantages and disadvantages. Additionally, this review summarises the major achievements and challenges of this method while identifying areas that require further exploration. These findings may contribute to a comprehensive understanding of the formation and stabilization mechanisms of ACs/CDs ICs and offer guidance for the selection and computational characterisation of CDs in the AC steady state.

Current and New Insights on Delivery Systems for Plant Sterols in Food

Plant sterols are minor bioactive components of food lipids, which are often used for the formulation of functional foods due to their cholesterol-lowering properties. However, they have low solubility and tend to crystallize, which may affect their biological effects, the sensory profile of the sterol-enriched food, and its consumer acceptability. Moreover, due to the unsaturated structure of sterols, they are susceptible to oxidation, so different encapsulation systems have been developed to improve their dispersibility/solubility, stability, delivery, and bioaccessibility. This chapter provides an overview of the main encapsulation systems currently used for plant sterols and their application in model and food systems, with a particular focus on their efficiency and impact on sterol bioaccessibility.

Recent advances in chiral selectors immobilization and chiral mobile phase additives in liquid chromatographic enantio-separations: A review

For decades now, the separation of chiral enantiomers of drugs has been gaining the interest and attention of researchers. In 1991, the first guidelines for development of chiral drugs were firstly released by the US-FDA. Since then, the development in chromatographic enantioseparation tools has been fast and variable, aiming at creating a suitable environment where the physically and chemically identical enantiomers can be separated. Among those tools, the immobilization of chiral selectors (CS) on different stationary phases and the chiral mobile phase additives (CMPA) which have been progressed and studied extensively. This review article highlights the major advances in immobilization of CS together with their different recognition mechanisms as well as CMPA as a cheaper and successful alternative for chiral stationary phases. Moreover, the role of molecular modeling tool as a pre-step in the choice of CS for evaluating possible interactions with different ligands has been pointed up. Illustrations of reported methods and updates for immobilized CS and CMPA have been included.

A Review on Cyclodextrins/Estrogens Inclusion Complexes

This review focuses on the methods of preparation and biological, physiochemical, and theoretical analysis of the inclusion complexes formed between estrogens and cyclodextrins (CDs). Because estrogens have a low polarity, they can interact with some cyclodextrins' hydrophobic cavities to create inclusion complexes, if their geometric properties are compatible. For the last forty years, estrogen-CD complexes have been widely applied in several fields for various objectives. For example, CDs have been used as estrogen solubilizers and absorption boosters in pharmaceutical formulations, as well as in chromatographic and electrophoretic procedures for their separation and quantification. Other applications include the removal of the endocrine disruptors from environmental materials, the preparation of the samples for mass spectrometric analysis, or solid-phase extractions based on complex formation with CDs. The aim of this review is to gather the most important outcomes from the works related to this topic, presenting the results of synthesis, in silico, in vitro, and in vivo analysis.

Hydroxypropyl-β-Cyclodextrin-Based Helichrysum italicum Extracts: Antioxidant and Cosmeceutical Activity and Biocompatibility

Two Helichrysum italicum extracts, OPT-1 (rich in phenolic acids) and OPT-2 (rich in total phenols and flavonoids), were prepared using hydroxypropyl-β-cyclodextrin (HP-β-CD)-assisted extraction. The prepared extracts were rich in phenolic compounds, including flavonoids and phenolic acids. GC-MS analysis of the extracts identified neryl acetate, neo-intermedeol, β-selinene, γ-curcumene, italidione I, and nerol as the main volatile components of the extracts, as well as plant sterols, γ-sitosterol, campesterol, and stigmasterol. The antioxidant (DPPH radical scavenging, reducing power, and a carotene linoleic acid assay) and cosmeceutical (anti-hyaluronidase, anti-tyrosinase, anti-lipoxygenase, ovalbumin anti-coagulation, and a UV-absorption assay) activity of the extracts in most of the assays was better than the activity of the applied positive controls. Especially low were the IC50 values of the extracts in the anti-hyaluronidase (14.31 ± 0.29 μL extract/mL and 19.82 ± 1.53 μL extract/mL for OPT-1 and OPT-2, respectively) and the anti-lipoxygenase (0.96 ± 0.11 μL extract/mL and 1.07 ± 0.01 μL extract/mL for OPT-1 and OPT-2, respectively) assays. The extracts were non-toxic to HaCaT cells in concentrations of up to 62.5 µL extract/mL assuring their status as excellent candidates for cosmeceutical product development appropriate for direct use in cosmetic products without solvent evaporation.

Thymus vulgaris Essential Oil in Beta-Cyclodextrin for Solid-State Pharmaceutical Applications

Antimicrobial resistance related to the misuse of antibiotics is a well-known current topic. Their excessive use in several fields has led to enormous selective pressure on pathogenic and commensal bacteria, driving the evolution of antimicrobial resistance genes with severe impacts on human health. Among all the possible strategies, a viable one could be the development of medical features that employ essential oils (EOs), complex natural mixtures extracted from different plant organs, rich in organic compounds showing, among others, antiseptic properties. In this work, green extracted essential oil of Thymus vulgaris was included in cyclic oligosaccharides cyclodextrins (CD) and prepared in the form of tablets. This essential oil has been shown to have a strong transversal efficacy both as an antifungal and as an antibacterial agent. Its inclusion allows its effective use because an extension of the exposure time to the active compounds is obtained and, therefore, a more marked efficacy, especially against biofilm-producing microorganisms such as P. aeruginosa and S. aureus, was registered. The efficacy of the tablet against candidiasis opens their possible use as a chewable tablet against oral candidiasis and as a vaginal tablet against vaginal candidiasis. Moreover, the registered wide efficacy is even more positive since the proposed approach can be defined as effective, safe, and green. In fact, the natural mixture of the essential oil is produced by the steam current method; therefore, the manufacturer employs substances that are not harmful, with very low production and management costs.

Bergamot Essential Oil: A Method for Introducing It in Solid Dosage Forms

Bergamot essential oil (BEO) possess antimicrobial, antiproliferative, anti-inflammatory, analgesic, neuroprotective, and cardiovascular effects. However, it is rich in volatile compounds, e.g., limonene, that are susceptible to conversion and degradation reactions. The aim of this communication was to prepare a conjugate based on a quaternary ammonium chitosan derivative (QA-Ch) and methyl-βCD (MCD), coded as BEO/QA-Ch-MCD, to encapsulate BEO in order to stabilize its volatile compounds, eliminate its unpleasant taste, and convert the oil in a solid dosage form. The obtained conjugate, BEO/QA-Ch-MCD, was highly soluble and had a percentage of extract association efficiency (AE %), in terms of polyphenols and limonene contents, of 22.0 ± 0.9 and 21.9 ± 1.2, respectively. Moreover, stability studies under UV stress in simulated gastric fluid showed that BEO/QA-Ch-MCD was more able to protect polyphenols and limonene from degradation compared to free BEO or BEO complexed with MCD (BEO/MCD). The complexation and subsequent lyophilization allowed the transformation of a liquid into a solid dosage form capable of eliminating the unpleasant taste of the orally administered oil and rendering the solid suitable to produce powders, granules, tablets, etc. These solid oral dosage forms, as they come into contact with physiological fluids, could generate nanosized agglomerates able to increase the stability of their active contents and, consequently, their bioavailability.

Hispolon Cyclodextrin Complexes and Their Inclusion in Liposomes for Enhanced Delivery in Melanoma Cell Lines

Hispolon, a phenolic pigment isolated from the mushroom species Phellinus linteus, has been investigated for anti-inflammatory, antioxidant, and anticancer properties; however, low solubility and poor bioavailability have limited its potential clinical translation. In this study, the inclusion complex of hispolon with Sulfobutylether-β-cyclodextrin (SBEβCD) was characterized, and the Hispolon-SBEβCD Complex (HSC) was included within the sterically stabilized liposomes (SL) to further investigate its anticancer activity against melanoma cell lines. The HSC-trapped-Liposome (HSC-SL) formulation was investigated for its sustained drug delivery and enhanced cytotoxicity. The inclusion complex in the solid=state was confirmed by a Job’s plot analysis, molecular modeling, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), Proton nuclear magnetic resonance (NMR) spectroscopy, and scanning electron microscopy (SEM). The HSC-SL showed no appreciable deviation in size (<150 nm) and polydispersity index (<0.2) and improved drug encapsulation efficiency (>90%) as compared to control hispolon liposomes. Individually incorporated hispolon and SBEβCD in the liposomes (H-CD-SL) was not significant in loading the drug in the liposomes, compared to HSC-SL, as a substantial amount of free drug was separated during dialysis. The HSC-SL formulation showed a sustained release compared to hispolon liposomes (H-SLs) and Hispolon-SBEβCD liposomes (H-CD-SLs). The anticancer activity on melanoma cell lines (B16BL6) of HSC and HSC-SL was higher than in H-CD-SL and hispolon solution. These findings suggest that HSC inclusion in the HSC-SL liposomes stands out as a potential formulation approach for enhancing drug loading, encapsulation, and chemotherapeutic efficiency of hispolon and similar water insoluble drug molecules.

Epigallocatechin Gallate Stabilized by Cyclodextrin Inactivates Influenza Virus and Human Coronavirus 229E

Natural products are attractive antiviral agents because they are environment-friendly and mostly harmless. Epigallocatechin gallate (EGCg), a type of catechin, is a well-known natural antiviral agent that can inhibit various viruses. However, EGCg easily oxidizes and loses its physiological activity. Although this problem can be overcome by combining EGCg with cyclodextrin (CD-EGCg), which makes it stable in water at high concentrations, the antiviral effect of this compound remains unclear. Here, we show that in Madin–Darby canine kidney (MDCK) and MRC-5 cells, CD-EGCg is cytotoxic for 50% of cells at 85.61 and 65.34 ppm, respectively. Furthermore, CD-EGCg mainly shows its antiviral effect during the adsorption step for all four influenza virus strains (median effect concentration (EC₅₀) was 0.93 to 2.78 ppm). Its antiviral effect post-adsorption is less intense, and no inhibitory effect is observed on influenza viruses pre-adsorption. Moreover, human coronavirus 229E (HCoV-229E) was inhibited at the adsorption step in short contact (EC₅₀ = 2.5 ppm) and long contact conditions (EC₅₀ = 0.5 ppm) by mixing CD-EGCg with HCoV-229E. These results suggest that CD-EGCg effectively inhibits various viruses that require an adsorption step, and is an effective tool for preventing infection.