Cyclodextrin complexes: Perspective from drug delivery and formulation

Polymerized cyclodextrin microparticles for sustained antibiotic delivery in lung infections

Pulmonary infections complicate chronic lung diseases requiring attention to both the pathophysiology and complexity associated with infection management. Patients with cystic fibrosis (CF) struggle with continuous bouts of pulmonary infections, contributing to lung destruction and eventual mortality. Additionally, CF patients struggle with airways that are highly viscous, with accumulated mucus creating optimal environments for bacteria colonization. The unique physiology and altered airway environment provide an ideal niche for bacteria to change their phenotype often becoming resistant to current treatments. Colonization with multiple pathogens at the same time further complicate treatment algorithms, requiring drug combinations that can challenge CF patient tolerance to treatment. The goal of this research initiative was to explore the utilization of a microparticle antibiotic delivery system, which could provide localized and sustained antibiotic dosing. The outcome of this work demonstrates the feasibility of providing efficient localized delivery of antibiotics to manage infection using both preclinical in vitro and in vivo CF infection models. The studies outlined in this manuscript demonstrate the proof-of-concept and unique capacity of polymerized cyclodextrin microparticles to provide site-directed management of pulmonary infections.

Characterization and drug solubilization of arginine-based ionic liquids - Impact of counterions and stoichiometry

Ionic liquids (ILs) exhibit very diverse physicochemical properties, such as non-volatility, stability, and miscibility, which render them excellent candidate excipients for multi-purpose use. Six novel arginine (Arg)-based ILs were obtained using a one-step ultrasound method. Salt formation was confirmed by Fourier-transform infrared (FTIR), Raman, and nuclear magnetic resonance (NMR) spectroscopies. Moreover, the effects of anions and molar ratio on the molecular states and thermal properties of Arg-ILs were investigated. In addition, the solubilization of drugs with different pKa and LogP values was attempted using Arg-ILs consisting of asparagine, proline, octanoic acid, and malic acid, respectively, and a comparative study was performed. Furthermore, the interaction mode between the drugs and ILs was determined by FTIR and Raman spectroscopy. Presumably, partial interaction between the component of ILs and drugs such as ofloxacin and valsartan occurred, whereas flurbiprofen and isosorbide mononitrate were dispersed in the viscous IL. The development of strategies for the application of ILs as solubilizers or carriers of active pharmaceutical ingredients is an extremely promising and wide avenue of research.

Improved triamcinolone acetonide-eluting contact lenses based on cyclodextrins and high hydrostatic pressure assisted complexation

Contact lenses (CLs) constitute an advantageous platform for the topical release of corticosteroids due to their prolonged contact with the eye. However, the lipophilic nature of corticosteroids hampers CLs' ability to release therapeutic amounts. Two approaches to improve loading and release of triamcinolone acetonide (TA) from poly(2-hydroxyethyl methacrylate)-based hydrogels were investigated: adding 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) to the monomers solution before polymerization (HEMA/i-CD) and an hydrogels' post-treatment with HP-β-CD (HEMA/p-CD). The effect of HP-β-CD and sterilization by high hydrostatic pressure (HHP) on the hydrogel properties (water content, oxygen and ion permeability, roughness, transmittance, and stiffness) was evaluated. The HEMA/i-CD hydrogels had stronger affinity for TA, sustaining its release for one day. HHP sterilization promoted the formation of cyclodextrin-TA complexes within the hydrogels, improving their drug-loading capacity »60 %. Cytotoxicity and irritability tests confirmed the safety of the therapeutic CLs. TA released from the hydrogels permeated through ocular tissues ex vivo and showed anti-inflammatory activity. Finally, a previously validated mathematical model was used to estimate the ability of the TA-loaded CLs to deliver therapeutic drug concentrations to the posterior part of the eye. Overall, HP-β-CD-containing CLs are promising candidates for the topical ocular application of TA as an alternative delivery system to intraocular injections.

Synergistic applications of cyclodextrin-based systems and metal-organic frameworks in transdermal drug delivery for skin cancer therapy

This review article explores the innovative field of eco-friendly cyclodextrin-based coordination polymers and metal-organic frameworks (MOFs) for transdermal drug delivery in the case of skin cancer therapy. We critically examine the significant advancements in developing these nanocarriers, with a focus on their unique properties such as biocompatibility, targeted drug release, and enhanced skin permeability. These attributes are instrumental in addressing the limitations inherent in traditional skin cancer treatments and represent a paradigm shift towards more effective and patient-friendly therapeutic approaches. Furthermore, we discuss the challenges faced in optimizing the synthesis process for large-scale production while ensuring environmental sustainability. The review also emphasizes the immense potential for clinical applications of these nanocarriers in skin cancer therapy, highlighting their role in facilitating targeted, controlled drug release which minimizes systemic side effects. Future clinical applications could see these nanocarriers being customized to individual patient profiles, potentially revolutionizing personalized medicine in oncology. With further research and clinical trials, these nanocarriers hold the promise of transforming the landscape of skin cancer treatment. With this study, we aim to provide a comprehensive overview of the current state of research in this field and outline future directions for advancing the development and clinical application of these innovative nanocarriers.

Recent developments in the use of nanocrystals to improve bioavailability of APIs

Nanocrystals refer to materials with at least one dimension smaller than 100 nm, composing of atoms arranged in single crystals or polycrystals. Nanocrystals have significant research value as they offer unique advantages over conventional pharmaceutical formulations, such as high bioavailability, enhanced targeting selectivity and controlled release ability and are therefore suitable for the delivery of a wide range of drugs such as insoluble drugs, antitumor drugs and genetic drugs with broad application prospects. In recent years, research on nanocrystals has been progressively refined and new products have been launched or entered the clinical phase of studies. However, issues such as safety and stability still stand that need to be addressed for further development of nanocrystal formulations, and significant gaps do exist in research in various fields in this pharmaceutical arena. This paper presents a systematic overview of the advanced development of nanocrystals, ranging from the preparation approaches of nanocrystals with which the bioavailability of poorly water-soluble drugs is improved, critical properties of nanocrystals and associated characterization techniques, the recent development of nanocrystals with different administration routes, the advantages and associated limitations of nanocrystal formulations, the mechanisms of physical instability, and the enhanced dissolution performance, to the future perspectives, with a final view to shed more light on the future development of nanocrystals as a means of optimizing the bioavailability of drug candidates. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

The synergistic effect of metal ions and amino acids on the fermentation of β-CGTase-producing statin DF257

To meet the growing demand of β-cyclodextrin (CD), innovative approaches are being developed to improve the production of β-CD by β-cyclodextrin glucose-transferase (CGTase). Considering the low production and efficacy of wild-type β-CGTase-producing strains, to obtain the strains suitable for industrial production of β-CGTase, the recombinant engineered bacteria strain DF257 is constructed by transfecting with the plasmid expressing His tagged β-CGTase. The fermentation of β-CGTase-expressing DF257 was optimized in the presence of different metal ions, amino acids, and incubated at a certain temperature and pH condition. The results showed that when Mg2+ and isoleucine were added into the culture medium at 0.5 mM and 0.5 g/L, respectively, the enzyme activity of β-CGTase increased significantly after incubation at 37 °C with the initial pH of 7.5. In addition, the optimal temperature for β-CGTase with the addition of Mg2+ and isoleucine was also determined. The T half of β-CGTase under 50, 55, 60 and 65 °C was 9.5, 8.8, 6.2 and 1.2 h, respectively. Further investigation showed that β-CGTase kept stable under the pH 6.0-10.0, and pH 7.5 was identified as the optimal pH condition of β-CGTase. With the addition of Mg2+ and isoleucine, the kinetic properties of β-CGTase in the cyclization reaction had a similar form with Michaelis equation under 50 °C and pH 7.5, and Vmax, Km, and Kcat was 3.74 mg/mL/min, 3.28 mg/mL, and 31.17/s, respectively. The possible underlying mechanism by which Mg2+ and isoleucine synergistically improved the thermostability of β-CGTase was investigated by the surface hydrophobicity index analysis, Fourier transform infrared spectroscopy and differential scanning calorimetry (DSC) analysis. The results indicated that addition of Mg2+ and isoleucine maintained the spatial structure and enhanced the thermostability of β-CGTase. These findings provided a theoretical basis for realizing the industrialization application of β-CGTase in promoting the generation of β-CD.

Synthesis and activation of pH-sensitive metal-organic framework Sr(BDC)∞ for oral drug delivery

Metal-organic frameworks (MOFs) are widely used in the biomedical industry. In this study, we developed a new method for obtaining a metal-organic structure of strontium and terephthalic acid, Sr(BDC), and an alternative activation method for removing DMF from the pores. Sr(BDC) MOFs were successfully prepared and characterized by XRD, FTIR, TGA, and SEM. The importance of the activation steps was confirmed by TGA, which showed that the Sr(BDC)(DMF) sample can contain up to a quarter of the solvent (DMF) before activation. In our study, IR spectroscopy confirmed the possibility of removing DMF by ethanol treatment from the Sr-BDC crystals. A comparative analysis of the effect of the activation method on the specific surface and pore size of Sr-BDC and its sorption properties using the model drug doxorubicin showed that due to the undeveloped surface of the Sr-(BDC)(DMF) sample, it is not possible to obtain an adsorption isotherm and determine the pore size distribution, thus showing the importance of the activation step. Cytotoxicity and apoptosis assays were carried out to study the biological activity of MOFs, and we observed relatively low toxicity in the tested concentration range after 48 h, with over 92% cell survival for Sr(BDC)(DMF) and Sr(BDC)(260 °C), with a decrease only in the highest concentration (800 mg L-1). Similar results were observed in our apoptosis assays, as they revealed low apoptotic population generation of 2.52%, 3.23%, and 2.77% for Sr(BDC)(DMF), Sr(BDC) and Sr(BDC)(260 °C), respectively. Overall, the findings indicate that ethanol-activated Sr(BDC) shows potential as a safe and effective material for drug delivery.

Exploring the Potential of Nanogels: From Drug Carriers to Radiopharmaceutical Agents

Nanogels open up access to a wide range of applications and offer among others hopeful approaches for use in the field of biomedicine. This review provides a brief overview of current developments of nanogels in general, particularly in the fields of drug delivery, therapeutic applications, tissue engineering, and sensor systems. Specifically, cyclodextrin (CD)-based nanogels are important because they have exceptional complexation properties and are highly biocompatible. Nanogels as a whole and CD-based nanogels in particular can be customized in a wide range of sizes and equipped with a desired surface charge as well as containing additional molecules inside and outside, such as dyes, solubility-mediating groups or even biological vector molecules for pharmaceutical targeting. Currently, biological investigations are mainly carried out in vitro, but more and more in vivo applications are gaining importance. Modern molecular imaging methods are increasingly being used for the latter. Due to an extremely high sensitivity and the possibility of obtaining quantitative data on pharmacokinetic and pharmacodynamic properties, nuclear methods such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) using radiolabeled compounds are particularly suitable here. The use of radiolabeled nanogels for imaging, but also for therapy, is being discussed.

Change in the Kinetic Regime of Aggregation of Yeast Alcohol Dehydrogenase in the Presence of 2-Hydroxypropyl-β-cyclodextrin

Chemical chaperones are low-molecular-weight compounds that suppress protein aggregation. They can influence different stages of the aggregation process-the stage of protein denaturation, the nucleation stage and the stage of aggregate growth-and this may lead to a change in the aggregation kinetic regime. Here, the possibility of changing the kinetic regime in the presence of a chemical chaperone 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) was investigated for a test system based on the thermally induced aggregation of yeast alcohol dehydrogenase (yADH) at 56 °C. According to differential scanning calorimetry data, 2-HP-β-CD did not affect the stage of the protein molecule unfolding. Dynamic light scattering data indicated changes in the aggregation kinetics of yADH during the nucleation and aggregate growth stages in the presence of the chaperone. The analysis of kinetic curves showed that the order of aggregation with respect to protein (nc), calculated for the stage of aggregate growth, changed from nc = 1 to nc = 2 with the addition of 100 mM 2-HP-β-CD. The mechanism of 2-HP-β-CD action on the yADH thermal aggregation leading to a change in its kinetic regime of aggregation is discussed.

Ternary cyclodextrin systems of terbinafine hydrochloride inclusion complexes: Solventless preparation, solid-state, and in vitro characterization

Cyclodextrins (CD) are used extensively in the pharmaceutical industry to improve the water solubility and bioavailability of drugs. Preparing ternary systems by applying a third component can enhance these beneficial effects. The complexation methods of these ternary systems are the same as those of two-component complexes. These methods are solvent (co-evaporation, co-precipitation, etc.) or solventless "green" techniques (co-grinding, microwave irradiation, etc.). Using solvent-free methods is considered to be an economically and environmentally desirable technology. This study aimed to prepare ternary systems by the co-grinding method and evaluate the effect of a third component by comparing it to products obtained by solvent methods, binary systems, and marketed products. For that, we used terbinafine hydrochloride as a model drug, sulfobutyl-ether-beta-cyclodextrin as a complexation agent and 5 or 15 w/w% of polyvinylpyrrolidone K-90 (PVP) or hydroxypropyl methylcellulose (HPMC) as auxiliary components. Physicochemical evaluation (X-Ray Diffractometry, Differential Scanning Calorimetry, Thermogravimetry) showed that new solid phases were formed, while Scanning Electron Microscopy was performed to study morphological aspects of the products. Fourier transform infrared spectroscopic measurements suggested different intermolecular interactions depending on the type of polymer. In vitro dissolution studies showed beneficial effects of CD and further improvement with the applied polymers. Products showed less cell toxicity with one exception. Both polymers enhanced the physicochemical and in vitro properties, suggesting a greater bioavailability of the model drug. However, the percentage of polymers applied did not appear to be an influencing factor for these properties.

Harnessing role of sesamol and its nanoformulations against neurodegenerative diseases

Sesamol is a lignan of sesame seeds and a natural phenolic molecule that has emerged as a useful medical agent. Sesamol is a non-toxic phytoconstituent, which exerts certain valuable effects in the management of cancer, diabetes, cardiovascular diseases, neurodegenerative diseases (NDs), etc. Sesamol is known to depict its neuroprotective role by various mechanisms, such as metabolic regulators, action on oxidative stress, neuroinflammation, etc. However, its poor oral bioavailability, rapid excretion (as conjugates), and susceptibility to gastric irritation/toxicity (particularly in rats' forestomach) may restrict its effectiveness. To overcome the associated limitations, novel drug delivery system-based formulations of sesamol are emerging and being researched extensively. These can conjugate with sesamol and enhance the bioavailability and solubility of free sesamol, along with delivery at the target site. In this review, we have summarized various research works highlighting the role of sesamol on various NDs, including Alzheimer's disease, Huntington's disease, Amyotrophic lateral sclerosis, and Parkinson's disease. Moreover, the formulation strategies and neuroprotective role of sesamol-based nano-formulations have also been discussed.

Nanotechnology-Based Drug Delivery Systems in the Transdermal Treatment of Melanoma

The incidence rate of melanoma is dramatically increasing worldwide, raising it to the fifth most common cancer in men and the sixth in women currently. Resistance generally occurs to the agents used in chemotherapy; besides their high toxicity destroys the normal cells. This study reviewed a detailed summary of the structure, advantages, and disadvantages of nanotechnology-based drug delivery systems in the treatment of melanoma, as well as some nanocarrier applications in animal models or clinical studies. Respective databases were searched for the target keywords and 93 articles were reviewed and discussed. A close study of the liposomes, niosomes, transferosomes, ethosomes, transethosomes, cubosomes, dendrimers, cyclodextrins, solid lipid nanoparticles, and carbon nanotubes (CNTs) was conducted. It was found that these nanocarriers could inhibit metastasis and migration of melanoma cells and decrease cell viability. Conclusively, some nanocarriers like liposomes, niosomes, and transferosomes have been discussed as superior to conventional therapies for melanoma treatment.

Novel Biphasic In Vitro Dissolution Method Correctly Predicts the Oral Bioavailability of Curcumin in Humans

In vitro dissolution methods correctly predicting in vivo bioavailability of compounds from complex mixtures are lacking. We therefore used data on the in vivo performance of bioavailability-improved curcumin formulations to implement an in vivo predictive dissolution method (BiPHa+). BiPHa+ was applied for the characterization of eight curcumin formulations previously studied in a strictly controlled pharmacokinetic human trial. During dissolution, the dissolved proportion of curcumin in the aqueous medium underwent a formulation-dependent reduction, whereas the proportion remained stable in the organic layer. Compared with conventional dissolution systems, BiPHa+ was superior in terms of in vivo-relevant formulation characterization. All formulations could be precisely categorized according to their bioavailability in humans. In vitro-in vivo relationships for each dissolution method were established, with BiPHa+ providing the highest degree of linearity (r2 = 0.9975). The BiPHa+ assay correctly predicted the bioavailability of curcuminoids from complex mixtures and provided mechanistic information about formulation-dependent release characteristics.

Effect of Cyclodextrin Complex Formation on Solubility Changes of Each Drug Due to Intermolecular Interactions between Acidic NSAIDs and Basic H2 Blockers

One of the solubilization of poorly water-soluble drugs is the use of cyclodextrin (CD)-based inclusion complexes. On the other hand, few studies have investigated how CD functions on the solubility of drugs in the presence of multiple drugs that interact with each other. In this study, we used indomethacin (IND) and diclofenac (DIC) as acidic drugs, famotidine (FAM) and cimetidine (CIM) as basic drugs, and imidazole (IMZ), histidine (HIS), and arginine (ARG) as compounds structurally similar to basic drugs. We attempted to clarify the effect of β-CD on the solubility change of each drug in the presence of multiple drugs. IND and DIC formed a eutectic mixture in the presence of CIM, IMZ, and ARG, which greatly increased the intrinsic solubility of the drugs as well as their affinity for β-CD. Furthermore, the addition of high concentrations of β-CD to the DIC-FAM combination, which causes a decrease in solubility due to the interaction, improved the solubility of FAM, which was decreased in the presence of DIC. These results indicate that β-CD synergistically improves the solubility of drugs in drug-drug combinations, where the solubility is improved, whereas it effectively improves the dissolution rate of drugs in situations where the solubility is reduced by drug-drug interactions, such as FAM-DIC. This indicates that β-CD can be used to improve the physicochemical properties of drugs, even when they are administered in combination with drugs that interact with each other.

An oral polyphenol host-guest nanoparticle for targeted therapy of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a global public health challenge that affects millions of people. Current medical treatments for IBD are not fully effective and may cause undesirable side effects on patients. Thus, there is an urgent need for safe, simple, and efficacious strategies to treat IBD in clinical settings. Here, we develop an oral polyphenol nanoparticle (PDT) by assembling dexamethasone sodium phosphate (DSP)-loaded poly-β-cyclodextrin with tannic acid via host-guest interactions for treating IBD. This one-step assembly process is rapid (within 10 s), reproducible, and free of harmful chemical agents, which can facilitate its clinical translation. PDT is negatively charged due to the three components, which enable it to specifically target the positively charged inflamed colonic mucosa through electrostatic attraction, thus localizing the drug at the inflamed site to reduce systemic exposure and side effects. Furthermore, PDT exhibits a strong reactive oxygen species (ROS)-scavenging ability derived from the tannic acid component, which can alleviate ROS-mediated inflammatory responses and ameliorate IBD symptoms. Compared with free DSP, PDT demonstrates sustained DSP release behavior in vitro and in vivo, as well as enhanced therapeutic efficacy in a colitis mouse model. These results suggest that PDT might be a potential therapeutic agent for the treatment of IBD. Moreover, this facile polyphenol host-guest assembly strategy may provide a promising drug-delivery platform for treating various diseases STATEMENT OF SIGNIFICANCE: To develop safe and effective treatments for inflammatory bowel disease (IBD), we have designed an oral polyphenol nanoparticle (PDT) using the host-guest assembly of dexamethasone sodium phosphate (DSP)-loaded poly-β-cyclodextrin with tannic acid. Through in vitro and in vivo experiments, PDT has demonstrated remarkable inflammation-targeting, ROS-scavenging, and anti-inflammatory properties, along with sustained release of DSP. Moreover, in an IBD mouse model, PDT has shown significantly improved therapeutic efficacy compared to free DSP. The host-guest assembly strategy employed for PDT is noteworthy for its rapidity, reproducibility, and safety due to the absence of harmful chemicals, holding great promise for designing a diverse range of nanomedicines customized for treating various diseases.

Bioresponsive and multifunctional cyclodextrin-based non-viral nanocomplexes in cancer therapy: Building foundations for gene and drug delivery, immunotherapy and bioimaging

The interest towards application of nanomaterials in field of cancer therapy is that the drawbacks of conventional therapies including chemoresistance, radio-resistance and lack of specific targeting of tumor cells can be solved by nanotechnology. Cyclodextrins (CDs) are amphiphilic cyclic oligosaccharides that can be present in three forms of α-, β- and γ-CDs, and they can be synthesized from natural sources. The application of CDs in cancer shows an increasing trend due to benefits of these nanocomplexes in improving solubility and bioavailability of current bioactives and therapeutics for cancer. CDs are widely utilized in delivery of drugs and genes in cancer therapy, and by targeted delivery of these therapeutics into target site, they improve anti-proliferative and anti-cancer potential. The blood circulation time and tumor site accumulation of therapeutics can be improved using CD-based nanostructures. More importantly, the stimuli-responsive types of CDs including pH-, redox- and light-sensitive types can accelerate release of bioactive compound at tumor site. Interestingly, the CDs are able to mediate photothermal and photodynamic impact in impairing tumorigenesis in cancer, enhancing cell death and improving response to chemotherapy. In improving the targeting ability of CDs, their surface functionalization with ligands has been conducted. Moreover, CDs can be modified with green products such as chitosan and fucoidan, and they can be embedded in green-based nanostructures to suppress tumorigenesis. The internalization of CDs into tumor cells can occur through endocytosis and this can be clethrin-, caveolae- or receptor-mediated endocytosis. Furthermore, CDs are promising candidates in bioimaging, cancer cell and organelle imaging as well as isolating tumor cells. The main benefits of using CDs in cancer therapy including sustained and low release of drugs and genes, targeted delivery, bioresponsive release of cargo, ease of surface functionalization and complexation with other nanostructures. The application of CDs in overcoming drug resistance requires more investigation.

Biopharmaceutical and nanotoxicological aspects of cyclodextrins for non-invasive topical treatments: A critical review

Cyclodextrins are nanometric cyclic oligosaccharides with amphiphilic characteristics that increase the stability of drugs in pharmaceutical forms and bioavailability, in addition to protecting them against oxidation and UV radiation. Some of their characteristics are low toxicity, biodegradability, and biocompatibility. They are divided into α-, β-, and γ-cyclodextrins, each with its own particularities. They can undergo surface modifications to improve their performances. Furthermore, their drug inclusion complexes can be made by various methods, including lyophilization, spray drying, magnetic stirring, kneading, and others. Cyclodextrins can solve several problems in drug stability when incorporated into dosage forms (including tablets, gels, films, nanoparticles, and suppositories) and allow better topical biological effects of drugs at administration sites such as skin, eyeballs, and oral, nasal, vaginal, and rectal cavities. However, as they are nanostructured systems and some of them can cause mild toxicity depending on the application site, they must be evaluated for their nanotoxicology and nanosafety aspects. Moreover, there is evidence that they can cause severe ototoxicity, killing cells from the ear canal even when applied by other administration routes. Therefore, they should be avoided in otologic administration and should have their permeation/penetration profiles and the in vivo hearing system integrity evaluated to certify that they will be safe and will not cause hearing loss.

Thiolated α-cyclodextrin: The likely smallest drug carrier providing enhanced cellular uptake and endosomal escape

This study aimed to evaluate the effect of thiolated α-cyclodextrin (α-CD-SH) on the cellular uptake of its payload. For this purpose, α-CD was thiolated using phosphorous pentasulfide. Thiolated α-CD was characterized by FT-IR and ¹H NMR spectroscopy, differential scanning calorimetry (DSC), and powder X-ray diffractometry (PXRD). Cytotoxicity of α-CD-SH was evaluated on Caco-2, HEK 293, and MC3T3 cells. Dilauryl fluorescein (DLF) and coumarin-6 (Cou) serving as surrogates for a pharmaceutical payload were incorporated in α-CD-SH, and cellular uptake was analyzed by flow cytometry and confocal microscopy. Endosomal escape was investigated by confocal microscopy and hemolysis assay. Results showed no cytotoxic effect within 3 h, while dose-dependent cytotoxicity was observed within 24 h. The cellular uptake of DLF and Cou was up to 20- and 11-fold enhanced by α-CD-SH compared to native α-CD, respectively. Furthermore, α-CD-SH provided an endosomal escape. According to these results, α-CD-SH is a promising carrier to shuttle drugs into the cytoplasm of target cells.

Anticancer activity of thymoquinone against breast cancer cells: Mechanisms of action and delivery approaches

The rising incidence of breast cancer has been a significant source of concern in the medical community. Regarding the adverse effects and consequences of current treatments, cancers' health, and socio-economical aspects have become more complicated, leaving research aimed at improved or new treatments on top priority. Medicinal herbs contain multitarget compounds that can control cancer development and advancement. Owing to Nigella Sativa's elements, it can treat many disorders. Thymoquinone (TQ) is a natural chemical derived from the black seeds of Nigella sativa Linn proved to have anti-cancer and anti-inflammatory properties. TQ interferes in a broad spectrum of tumorigenic procedures and inhibits carcinogenesis, malignant development, invasion, migration, and angiogenesis owing to its multitargeting ability. It effectively facilitates miR-34a up-regulation, regulates the p53-dependent pathway, and suppresses Rac1 expression. TQ promotes apoptosis and controls the expression of pro- and anti-apoptotic genes. It has also been shown to diminish the phosphorylation of NF-B and IKK and decrease the metastasis and ERK1/2 and PI3K activity. We discuss TQ's cytotoxic effects for breast cancer treatment with a deep look at the relevant stimulatory or inhibitory signaling pathways. This review discusses the various forms of polymeric and non-polymeric nanocarriers (NC) and the encapsulation of TQ for increasing oral bioavailability and enhanced in vitro and in vivo efficacy of TQ-combined treatment with different chemotherapeutic agents against various breast cancer cell lines. This study can be useful to a broad scientific community, comprising pharmaceutical and biological scientists, as well as clinical investigators.

Nickel sulfide and dysprosium-doped nickel sulfide nanoparticles: Dysprosium-induced variation in properties, in vitro chemo-photothermal behavior, and antibacterial activity

Newer materials for utilization in multi-directional therapeutic actions are investigated, considering delicate design principles involving size and shape control, surface modification, and controllable drug loading and release. Multi-faceted properties are imparted to the engineered nanoparticles, like magnetism, near-infrared absorption, photothermal efficiency, and suitable size and shape. This report presents nickel sulfide and dysprosium-doped nickel sulfide nanoparticles with poly-β-cyclodextrin polymer coating. The nanoparticles belong to the orthorhombic crystal systems, as indicated by X-ray diffraction studies. The size and shape of the nanoparticles are investigated using Transmission Electron Microscope (TEM) and a particle-size analyzer. The particles show soft ferromagnetic characteristics with definite and moderate saturation magnetization values. The nickel sulfide nanoparticles' in vitro anticancer and antibacterial activities are investigated in free and 5-fluorouracil/penicillin benzathine-loaded forms. The 5-fluorouracil-encapsulation efficiency of the nanoparticles is around 87%, whereas it is above 92% in the case of penicillin benzathine. Both drugs are released slowly in a controlled fashion. The dysprosium-doped nickel sulfide nanoparticles show better anticancer activity, and the efficacy is more significant than the free drug. The nanoparticles are irradiated with a low-power 808 nm laser. The dysprosium-doped nickel sulfide nanoparticles attain a higher temperature on irradiation, i.e., above 59 °C. The photothermal conversion efficiency of this material is determined, and the significance of dysprosium doping is discussed. Contrarily, the undoped nickel sulfide nanoparticles show more significant antibacterial activity. This study presents a novel designed nanoparticle system and the exciting variation of properties on dysprosium doping in nickel sulfide nanoparticles.

Recent Advances in the Pharmaceutical and Biomedical Applications of Cyclodextrin-Capped Gold Nanoparticles

The real problem in pharmaceutical preparation is drugs' poor aqueous solubility, low permeability through biological membranes, and short biological t_1/2. Conventional drug delivery systems are not able to overcome these problems. However, cyclodextrins (CDs) and their derivatives can solve these challenges. This article aims to summarize and review the history, properties, and different applications of cyclodextrins, especially the ability of inclusion complex formation. It also refers to the effects of cyclodextrin on drug solubility, bioavailability, and stability. Moreover, it focuses on preparing and applying gold nanoparticles (AuNPs) as novel drug delivery systems. It also studies the uses and effects of cyclodextrins in this field as novel drug carriers and targeting devices. The system formulated from AuNPs linked with CD molecules combines the advantages of both CD and AuNPs. Cyclodextrins benefit in increasing aqueous drug solubility, loading capacity, stability, and size control of gold NPs. Also, AuNPs are applied as diagnostic and therapeutic agents because of their unique chemical properties. Plus, AuNPs possess several advantages such as ease of detection, targeted and selective drug delivery, greater surface area, high loading efficiency, and higher stability than microparticles. In the present article, we tried to present the potential pharmaceutical applications of CD-derived AuNPs in biomedical applications including antibacterial, anticancer, gene-drug delivery, and various targeted drug delivery applications. Also, the article highlighted the role of CDs in the preparation and improvement of catalytic enzymes, the formation of self-assembling molecular print boards, the fabrication of supramolecular functionalized electrodes, and biosensors formation.

Optimization of the stability constants of the ternary system of diclofenac/famotidine/β-cyclodextrin by nonlinear least-squares method using theoretical equations

This study aimed to establish a new method for determining the stability constants of drug/β-cyclodextrin (β-CD) complexes when multiple drugs interacting with each other coexist in the solution of complexation. The basic drug famotidine (FAM) and the acidic drug diclofenac (DIC) were used as model drugs, their solubility decreasing owing to their mutual interaction. The dissolution of both FAM and DIC was characterized by A_L-type phase solubility diagrams in the presence of the other's 1:1 complex with β-CD. When the stability constant was calculated from the slope of the phase solubility diagram using the conventional phase solubility diagram method, it was modified in the presence of the other drug. However, by performing optimization calculations that considered the interactions between the drug/β-CD complex and the drug, drug/β-CD complexes, and drugs, we were able to accurately calculate the stability constant of DIC/β-CD and FAM/β-CD complexes even in the presence of FAM and DIC, respectively. The results of the solubility profile indicated that various molecular species, which are attributed to drug-drug and drug/β-CD interactions, interfere with the values of the dissolution rate constants and saturated concentration in the solubility profiles.

Inclusion Complexation of S-Nitrosoglutathione for Sustained Nitric Oxide Release from Catheter Surfaces: A Strategy to Prevent and Treat Device-Associated Infections

S-Nitrosoglutathione (GSNO) is a nontoxic nitric oxide (NO)-donating compound that occurs naturally in the human body. The use of GSNO to deliver exogenous NO for therapeutic and protective applications is limited by the high lability of dissolved GSNO in aqueous formulations. In this paper, we report a host-guest chemistry-based strategy to modulate the GSNO reactivity and NO release kinetics for the design of anti-infective catheters and hydrogels. Cyclodextrins (CDs) are host molecules that are typically used to encapsulate hydrophobic guest molecules into their hydrophobic cavities. However, we found that CDs form inclusion complexes with GSNO, an extremely hydrophilic molecule with a solubility of over 1 M at physiological pH. More interestingly, the host-guest complexation reduces the decomposition reactivity of GSNO in the order of αCD > γCD > hydroxypropyl βCD. The lifetime of 0.1 M GSNO is increased to up to 15 days in the presence of CDs at 37 °C, which is more than twice the lifetime of free GSNO. Quantum chemistry calculations indicate that GSNO in αCD undergoes a conformational change that significantly reduces the S-NO bond distance and increases its stability. The calculated S-NO bond dissociation enthalpies of free and complexed GSNO well agree with the experimentally observed GSNO decomposition kinetics. The NO release from GSNO-CD solutions, compared to GSNO solutions, has suppressed initial bursts and extended durations, enhancing the safety and efficacy of NO-based therapies and device protections. In an example application as an anti-infective lock solution for intravascular catheters, the GSNO-αCD solution exhibits potent antibacterial activities for both planktonic and biofilm bacteria, both intraluminal and extraluminal environments, both prevention and treatment of infections, and against multiple bacterial strains, including a multidrug-resistant strain. In addition to solutions, the inclusion complexation also enables the preparation of GSNO hydrogels with enhanced stability and improved antibacterial efficacy. Since methods to suppress and control the GSNO decomposition rate are rare, this supramolecular strategy provides new opportunities for the formulation and application of this natural NO donor.

Formulation Strategies for Enhancing Pharmaceutical and Nutraceutical Potential of Sesamol: A Natural Phenolic Bioactive

Natural plants and their products continue to be the major source of phytoconstituents in food and therapeutics. Scientific studies have evidenced the benefits of sesame oil and its bioactives in various health conditions. Various bioactives present in it include sesamin, sasamolin, sesaminol, and sesamol; among these, sesamol represents a major constituent. This bioactive is responsible for preventing various diseases including cancer, hepatic disorders, cardiac ailments, and neurological diseases. In the last decade, the application of sesamol in the management of various disorders has attracted the increasing interest of the research community. Owing to its prominent pharmacological activities, such as antioxidant, antiinflammatory, antineoplastic, and antimicrobial, sesamol has been explored for the above-mentioned disorders. However, despite the above-mentioned therapeutic potential, its clinical utility is mainly hindered owing to low solubility, stability, bioavailability, and rapid clearance issues. In this regard, numerous strategies have been explored to surpass these restrictions with the formulation of novel carrier platforms. This review aims to describe the various reports and summarize the different pharmacological activities of sesamol. Furthermore, one part of this review is devoted to formulating strategies to improve sesamol's challenges. To resolve the issues such as the stability, low bioavailability, and high systemic clearance of sesamol, novel carrier systems have been developed to open a new avenue to utilize this bioactive as an efficient first-line treatment for various diseases.

Solid-State Preparation and Characterization of 2-Hydroxypropylcyclodextrins-Iodine Complexes as Stable Iodophors

The use of iodine as antiseptic poses some issues related to its low water solubility and high volatility. Stable solid iodine-containing formulations are highly advisable and currently limited to the povidone-iodine complex. In this study, complexes of molecular iodine with 2-hydroxypropyl α-, β- and γ-cyclodextrins were considered water-soluble iodophors and prepared in a solid state by using three different methods (liquid-assisted grinding, co-evaporation and sealed heating). The obtained solids were evaluated for their iodine content and stability over time in different conditions using a fully validated UV method. The assessment of the actual formation of an inclusion complex in a solid state was carried out by thermal analysis, and the presence of iodine was further confirmed by SEM/EDX and XPS analyses. High levels of iodine content (8.3–10.8%) were obtained with all the tested cyclodextrins, and some influence was exerted by the employed preparation method. Potential use as solid iodophors can be envisaged for these iodine complexes, among which those with 2-hydroxypropyl-α-cyclodextrin were found the most stable, regardless of the preparation technique. The three prepared cyclodextrin–iodine complexes proved effective as bactericides against S. epidermidis.

Copper (II) Species with Improved Anti-Melanoma and Antibacterial Activity by Inclusion in β-Cyclodextrin

To improve their biological activity, complexes [Cu(bipy)(dmtp)₂(OH₂)](ClO₄)₂·dmtp (1) and [Cu(phen)(dmtp)₂(OH₂)](ClO₄)₂·dmtp (2) (bipy 2,2'-bipyridine, phen: 1,10-phenantroline, and dmtp: 5,7-dimethyl-1,2,4-triazolo [1,5-a]pyrimidine) were included in β-cyclodextrins (β-CD). During the inclusion, the co-crystalized dmtp molecule was lost, and UV-Vis spectra together with the docking studies indicated the synthesis of new materials with 1:1 and 1:2 molar ratios between complexes and β-CD. The association between Cu(II) compounds and β-CD has been proven by the identification of the components' patterns in the IR spectra and powder XRD diffractograms, while solid-state UV-Vis and EPR spectra analysis highlighted a slight modification of the square-pyramidal stereochemistry around Cu(II) in comparison with precursors. The inclusion species are stable in solution and exhibit the ability to scavenge or trap ROS species (O₂·^- and HO·) as indicated by the EPR experiments. Moreover, the two inclusion species exhibit anti-proliferative activity against murine melanoma B16 cells, which has been more significant for (2)@β-CD in comparison with (2). This behavior is associated with a cell cycle arrest in the G0/G1 phase. Compared with precursors, (1a)@β-CD and (2a)@β-CD exhibit 17 and 26 times more intense activity against planktonic Escherichia coli, respectively, while (2a)@β-CD is 3 times more active against the Staphylococcus aureus strain.

Solubility Enhancement and Inhalation Delivery of Cyclodextrin-Based Inclusion Complex of Delamanid for Pulmonary Tuberculosis Treatment

Tuberculosis (TB) is a contiguous airborne disease caused by Mycobacterium tuberculosis (M.tb), primarily affecting the human lungs. The progression of drug-susceptible TB to drug-resistant strains, MDR-TB and XDR-TB, has become a global challenge toward eradicating TB. Conventional TB treatment involves frequent dosing and prolonged treatment regimens predominantly by an oral or invasive route, leading to treatment-related systemic adverse effects and patient's noncompliance. Pulmonary delivery is an attractive option as we could reduce dose, limit systemic side-effects, and achieve rapid onset of action. Delamanid (DLD), an antituberculosis drug, has poor aqueous solubility, and in this study, we aim to improve its solubility using cyclodextrin complexation. We screened different cyclodextrins and found that HP-β-CD resulted in a 54-fold increase in solubility compared to a 27-fold and 13-fold increase by SBE-β-CD and HP-ɣ-CD, respectively. The stability constant (265 ± 15 M^-1) and complexation efficiency (8.5 × 10^-4) suggest the formation of a stable inclusion complex of DLD and HP-β-CD in a 2:1 ratio. Solid-state characterization studies (DSC, PXRD, and NMR) further confirmed successful complexation of DLD in HP-β-CD. The nebulized DLD-CD complex solution showed a mass median aerodynamic diameter of 4.42 ± 0.62 μm and fine particle fraction of 82.28 ± 2.79%, suggesting deposition in the respiratory airways. In bacterial studies, minimum inhibitory concentration of DLD-CD complex was significantly reduced (four-fold) compared to free DLD in M.tb (H37Ra strain). Furthermore, accelerated stability studies confirmed that the inclusion complex was stable for 4 weeks with 90%w/w drug content. In conclusion, we increased the aqueous solubility of DLD through cyclodextrin complexation and improved its efficacy in vitro.

Methods to Improve the Solubility of Curcumin from Turmeric

Turmeric is a strong-taste component of spices characteristic of Indian cuisine. It is obtained from the turmeric rhizome (Curcumae longae rhizoma) and has been used for thousands of years not only for culinary purposes, but also for medicinal purposes. It contains a group of organic compounds called curcuminoids. Curcumin is the main representative of this group of compounds which is also most frequently studied. In recent years, bioactive curcuminoids (including curcumin in the first place) have become more and more popular due to a wide spectrum of their biological activity. The anticancer, antibacterial, anti-inflammatory, and antiaging effects of curcumin have been confirmed by numerous in vitro and in vivo studies, as well as in clinical trials. However, an obstacle to simple, clinical application of curcumin is its poor bioavailability (which is due to its hydrophobic nature) and its very weak water solubility. Therefore, many scientists are working on improving the solubility of curcumin in water, which is the topic of the present article. Attempts have been made to combine curcumin with nanoparticles (polysaccharide or silica). Nanosuspensions or complexes with cyclodextrins are also considered. A promising direction is the search for new polymorphic varieties as well as obtaining cocrystals with curcumin which are characterized by better water solubility.

Synthesis of Novel Pentacyclic Triterpenoid Derivatives that Induce Apoptosis in Cancer Cells through a ROS-dependent, Mitochondrial-Mediated Pathway

Betulinic acid (BA) and oleanolic acid (OA) are plant-derived conjugates found in various medicinal plants that have emerged as potential antitumor agents. Herein, a series of novel BA and OA derivatives were synthesized by conjugation with per-O-methylated-β-cyclodextrin (PM-β-CD), and their anticancer properties against a panel of three human cancer cell lines were evaluated. Two OA-PM-β-CD conjugates (48 and 50) were observed to be the most potent conjugates against the three cell lines (MCF-7, BGC-823, and HL-60), with a 15- to 20-fold decrease in the IC₅₀ values (IC₅₀: 6.06-8.47 μM) compared with their parental conjugate (OA). Annexin V-FITC/propidium iodide staining and Western blot analysis revealed that both conjugates induced apoptosis in HL-60 cells. Additionally, in the representative conjugate 48-treated HL-60 cells, a decrease in mitochondrial membrane potential and subsequent release of cytochrome c into the cytosol were observed, indicating the activation of the intrinsic apoptosis pathway. Furthermore, 48 dramatically induced the generation of reactive oxygen species (ROS) in HL-60 cells, and the corresponding effect could be reversed using the ROS scavenger N-acetylcysteine. Collectively, these results suggest that the novel pentacyclic triterpenoid derivatives trigger the intrinsic apoptotic pathways via the ROS-mediated activation of caspase-3 signaling, inducing cell death in human cancer cells.

A Fluorescein-Substituted Perbrominated Dodecaborate Cluster as an Anchor Dye for Large Macrocyclic Hosts and Its Application in Indicator Displacement Assays

Perhalogenated boron clusters derived from B₁₂Br₁₂^2-, a superchaotropic dianion with a globular icosahedral shape, serve as inorganic cavity binders for cyclodextrins (CDs), in particular for large CDs (γ-CD and δ-CD), with high binding affinity (K_a > 10⁶ M^-1) in aqueous solution. This opens the door for applications of this anchoring moiety by linking it to organic residues, prominently fluorescent dyes. We report here the synthesis of a novel fluorescein-substituted perbrominated dodecaborate cluster by a copper(I)-catalyzed azide-alkyne click reaction. The formation of host-guest inclusion complexes between the dodecaborate-modified fluorescein dye and CDs can be readily followed by optical titrations, which afforded a binding constant of ∼1 × 10⁴ M^-1 with γ-CD; that is, the cluster functionalization allows binding of an otherwise nonbinding dye to the macrocycle ("anchor dye"). The formation of the 1:1 host-guest inclusion complex between the dye and γ-CD occurs over a broad range of pH values, which allows its application as a sensitive reporter pair according to the indicator displacement method, e.g., for drug detection. In addition, the substituted dye shows outer-wall binding to cucurbiturils through the dodecaborate moiety, leading to the formation of aggregates and significant fluorescence quenching of the dye.

Design and Optimization of Rivaroxaban-Cyclodextrin-Polymer Triple Complex Formulation with Improved Solubility

Purpose

This study aimed to ensure the convenience of administration and reproducibility of efficacy, regardless of the meal, by improving the solubility of rivaroxaban (RIV).

Methods

RIV is a non-vitamin K antagonist oral anticoagulants that exhibits a coagulation effect by directly inhibiting coagulation factor Xa. However, RIV has a very low solubility; therefore, it must be administered with a meal at high doses. We used a drug- hydroxypropyl-beta-cyclodextrin (CD)-water-soluble polymer triple complex (R-C-P complex) to solubilize RIV. Using Minitab, we evaluated the effect of each factor on RIV solubility and developed an optimal R-C-P complex formulation. The amount of CD, amount of polymer, and polymer type were set as the independent variables X₁, X₂, and X₃, respectively. RIV solubility (Y₁) and dissolution rate for 45 min in pH 4.5 medium (Y₂) and pH 1.2 medium (Y₃) were set as response variables.

Results

The most efficient RIV solubilization effect was obtained from the composition using CD and HPMC 2208, and physicochemical properties and dissolution parameters were analyzed. RIV in the R-C-P complex was present in an amorphous form and showed high solubility. Unlike commercial products, it showed a 100% dissolution rate. The R-C-P complex formulation secured high RIV solubility and 100% release regardless of pH.

Conclusion

The results imply that high-dose RIV can be administered regardless of the meal, reducing the risk of changing the drug effect due to the patient's administration mistake.

Amalgamation of solid dispersion and melt adsorption techniques for augmentation of oral bioavailability of novel anticoagulant rivaroxaban

The objective of the present study was to evaluate the potential of solid dispersion adsorbate (SDA) to improve the solubility and bioavailability of rivaroxaban (RXN). SDA of RXN was developed by fusion method using PEG 4000 as carrier and Neusilin as adsorbent. A 3² full factorial design was utilized to formulate various SDAs. The selected independent variables were the amount of carrier (X₁) and amount of adsorbent (X₂). The responses measured were the time required for 85% drug release (Y₁) and saturated solubility (Y₂). MTT assay was employed for cytotoxicity studies on Caco-2 cells. In vivo pharmacokinetics and pharmacodynamic evaluations were carried out to assess the prepared SDA. Pre-compression evaluation of SDA suggests the prepared batches (B1-B9) possess adequate flow properties and could be used for compression of tablets. Differential scanning calorimetry and X-ray diffraction data signified the conversion of the crystalline form of drug to amorphous form, a key parameter accountable for improvement in drug dissolution. Optimization data suggests that the amount of carrier and amount of adsorbent significantly (P < 0.05) influence both dependent variables. Post-compression data signifies that the compressibility behavior of prepared tablets was within the official standard limits. A significant increase (P < 0.0001) in the in vitro dissolution characteristics of RXN was noticed in optimized SDA (> 85% in 10 min) as compared to the pure drug, marketed product, and directly compressible tablet. Cytotoxicity studies confirmed the nontoxicity of prepared RXN SDA tablets. RXN SDA tablets exhibited 2.79- and 1.85-fold higher AUC in comparison to RXN suspension and Xarelto tablets respectively indicating improved oral bioavailability. Higher bleeding time and percentage of platelet aggregation noticed with RXN SDA tablets in comparison to RXN suspension further substantiate the efficacy of the prepared formulation. In summary, the results showed the potential of RXN SDA tablets to enhance the bioavailability of RXN and hence can be an alternate approach of solid dosage form for its development for commercial application.

Cyclodextrin Inclusion Complexes and Their Application in Food Safety Analysis: Recent Developments and Future Prospects

Food safety issues are a major threat to public health and have attracted much attention. Therefore, exploring accurate, efficient, sensitive, and economical detection methods is necessary to ensure consumers' health. In this regard, cyclodextrins (CDs) are promising candidates because they are nontoxic and noncaloric. The main body of CDs is a ring structure with hydrophobic cavity and hydrophilic exterior wall. Due to the above characteristics, CDs can encapsulate small guest molecules into their cavities, enhance their stability, avoid agglomeration and oxidation, and, at the same time, interact through hydrogen bonding and electrostatic interactions. Additionally, they can selectively capture the target molecules to be detected and improve the sensitivity of food detection. This review highlights recent advances in CD inclusion technology in food safety analysis, covering various applications from small molecule and heavy metal sensing to amino acid and microbial sensing. Finally, challenges and prospects for CDs and their derivatives are presented. The current review can provide a reference and guidance for current research on CDs in the food industry and may inspire breakthroughs in this field.

Development of pediatric orally disintegrating mini-tablets containing atomoxetine hydrochloride-β-cyclodextrin inclusion complex using experimental design

OBJECTIVE

The aim of the study was to develop and evaluate characteristics of orally disintegrating mini-tablet (ODMT) formulations including atomoxetine hydrochloride (ATO)/β-cyclodextrin (β-CD) inclusion complex for pediatric therapy of attention deficit and hyperactivity disorder (ADHD).

METHODS

Design of experiment approach was used to develop ODMTs. The ODMTs were compressed using direct compression method with two different superdisintegrants (Parteck ODT^® and Ac-Di-Sol^®) and characterized with quality control tests. In vitro dissolution and taste studies were performed.

RESULTS

The hardness and friability values of the optimized three ODMT formulations were determined as 41.7 N, 42.4 N, and 40.8 N and 0.32%, 0.29%, and 0.42%, respectively. The disintegration time of all the optimized formulations was found to be less than one minute. In addition, dissolution profiles of ATO from optimized ODMTs were determined in four different dissolution media (distilled water, pH 1.2, 6.8, and 7.4) and it was determined that the maximum dissolved ATO amount reached at the end of 20 min.

CONCLUSION

As a conclusion, the novel formulation of ODMTs with ATO/β-CD inclusion complex was successfully developed for pediatric use.

Quercitrin loaded cyclodextrin based nanosponge as a promising approach for management of lung cancer and COVID-19

Lung cancer and pandemic acute respiratory disease, COVID-19, are examples of the most worldwide widespread diseases. The aim of the current study is to develop cyclodextrin based nanosponge (CD-NS) for loading the flavonoid drug, quercitrin (QCT). This is to improve its solubility in an attempt to enhance its activity against lung cancer as well as SARS-CoV-2 virus responsible for COVID-19. Preparation of CD-NS was performed by ultrasound-assisted synthesis method. Two CDs were employed, namely, β cyclodextrin (βCD) and 2-hydroxy propyl-β-cyclodextrin (2-HPβCD) that were crosslinked with diphenyl carbonate, one at a time. QCT loaded CD-NS revealed entrapment efficiency and particle size ranged between 94.17 and 99.03% and 97.10–325.90 nm, respectively. QCT loaded 2-HPβCD-NS revealed smaller particle size compared with that of QCT loaded βCD-NS. Zeta potential absolute values of the prepared formulations were >20 mV, indicating physically stable nanosystems. The selected formulations were investigated by Fourier transform infrared spectroscopy, X-ray powder diffraction and scanning electron microscopy which proved the formation of QCT loaded CD-NS exhibiting porous structure. QCT exhibited partial and complete amorphization in βCD-NS and 2-HPβCD-NS, respectively. In vitro release revealed an improved release of QCT from CD-NS formulations. The biological activity of free QCT and QCT loaded CD-NS was investigated against lung cancer cell line A549 as well as SARS-CoV-2 virus. The results revealed that IC₅₀ values of free QCT against lung cancer cell line A549 and SARS-CoV-2 were higher than those exhibited by QCT loaded CD-NS by 1.57–5.35 and 5.95–26.95 folds, respectively. QCT loaded 2-HPβCD-NS revealed enhanced in vitro release and superior biological activity compared with QCT loaded βCD-NS.

Stability, Antioxidant Activity and Intestinal Permeation of Oleuropein Inclusion Complexes with Beta-Cyclodextrin and Hydroxypropyl-Beta-Cyclodextrin

Compared to beta-cyclodextrins (beta-CD), hydroxypropyl-beta-cyclodextrins (HP-beta-CD) are a more popular material used to prepare inclusion complexes due to their superior solubility and intestinal absorption. In this study, oleuropein (OL) inclusion complexes with beta-CD (beta-CD:OL) and HP-beta-CD (HP-beta-CD:OL) were prepared and the formation of inclusion complexes was validated by IR, PXRD, and DSC. A phase solubility test showed that the lgK (25 °C) and binding energy of beta-CD:OL and HP-beta-CD:OL was 2.32 versus 1.98, and −6.1 versus −24.66 KJ/mol, respectively. Beta-CD:OL exhibited a more powerful effect than HP-beta-CD:OL in protecting OL from degradation upon exposure to light, high temperature and high humidity. Molecular docking, peak intensity of carbonyls in IR, and ferric reducing power revealed that beta-CD:OL formed more hydrogen bonds with the unstable groups of OL. Both inclusion complexes significantly enhanced the solubility, intestinal permeation and antioxidant activity of OL (p < 0.05). Though HP-beta-CD:OL had higher solubility and intestinal absorption over beta-CD:OL, the difference was not significant (p > 0.05). The study implies that lower binding energy is not always associated with the higher stability of a complex. Beta-CD can protect a multiple-hydroxyl compound more efficiently than HP-beta-CD with the intestinal permeation comparable to HP-beta-CD complex.

Hydroxypropyl Beta Cyclodextrin as a Potential Surface Modifier for Paclitaxel Nanocrystals

Paclitaxel (PTX) is a hydrophobic chemotherapeutic agent cytotoxic against many serious cancers. This study aimed at designing novel PTX nanocrystals (PTX-NCs) coated with the biocompatible and biodegradable hydroxypropyl-beta-cyclodextrin (HPβCD) polymer with specific characteristics through the formation of a non-inclusion complex. Briefly, PTX-NCs were prepared by the anti-solvent method followed by homogenization. Then, the surface of the prepared PTX-NCs was modified using the HPβCD coat (HPβCD-PTX-NCs). The prepared nanocrystals, both coated and uncoated, were characterized in terms of size, polydispersity index, charge, morphology, and stability. Moreover, the nanocrystals were investigated using powder X-ray diffraction (PXRD), differential scanning calorimeter (DSC), and Fourier transform infrared spectroscopy (FTIR). As well, the in vitro release of PTX from the nanocrystals was determined under conditions similar to the IV route of administration. Furthermore, the tendency of the nanocrystals to induce hemolysis was investigated. Results indicated that the size was about 241.4 and 310.5 nm, the polydispersity index was 0.14 and 0.21, and the zeta potential was about - 22.6 and - 16.4 mV for PTX-NCs and HPβCD-PTX-NCs, respectively. Additionally, the PXRD, FTIR, and DSC profiles can be explained by the NCs' integrity and coat formation. The SEM images showed that both PTX-NCs and HPβCD-PTX-NCs have rod-like structures. Moreover, HPβCD-PTX-NCs had significantly superior in vitro release than both PTX-NCs and PTX. Interestingly, the hemolytic assay showed that HPβCD-PTX-NCs had a more efficient and safer profile than PTX-NCs. This study emphasized that HPβCD could be an interesting candidate for the surface modification of PTX-NCs providing superior properties such as release and safety profiles.

The impact of the size of acetylated cyclodextrin on the stability of amorphous metronidazole

Modified oligosaccharides with cyclic topology seem to be promising excipients for the preparation of Amorphous Solid Dispersions (ASDs), especially with those Active Pharmaceutical Ingredients (APIs), which have a strong crystallization tendency from the amorphous/glassy state. Herein, the usefulness of two acetylated cyclodextrins (ac-α-CD and ac-β-CD) with various molecular weights (M_w) as stabilizers for the supercooled metronidazole (Met) has been discussed. X-ray diffraction (XRD) studies carried out on Met-acCDs mixtures (prepared in molar ratios from 1:2 to 5:1) showed that the system with ac-α-CD containing the highest amount of API (5:1 m/m) crystallizes immediately after preparation, whereas all Met-ac-β-CD ASDs remain stable. What is more, long-term XRD measurements confirmed that the Met-ac-α-CD 2:1 m/m system crystallizes after 100 days of storage in contrast to the same system containing ac-β-CD. The non-isothermal calorimetric data revealed that the activation barrier for crystallization (E_cr) in ASDs with the oligosaccharide having a greater M_w (i.e., composed of seven acGLU molecules) is slightly higher. Finally, to explain the differences in behavior between the mixtures with both acCDs, infrared studies, DFT calculations and Molecular Dynamics simulations were performed. All methods excluded the scenario of API incorporation inside the acCDs' core. On the other hand, obtained results suggested that in comparison to ac-α-CD, the greater amount of Met molecules might be bounded on the outside surface of ac-β-CD. Therefore, this modified saccharide is a better stabilizer of the examined API.

Cyclodextrin Derivative Enhances the Ophthalmic Delivery of Poorly Soluble Azithromycin

Azithromycin (AZM), a macrolide antibiotic used for the treatment of chlamydial conjunctivitis, is less effective for the treatment of this disease due to its poor bioavailability (38%). Various alternatives have been developed for improving the physicochemical properties (i.e., solubility) of the AZM without much success. To overcome the problems associated with AZM, an inclusion complex employing a modified cyclodextrin, i.e., sulfobutylether-β-cyclodextrin (SBE-β-CD), was prepared and characterized by phase solubility studies and PXRD techniques. The results portrayed the formation of an inclusion complex of AZM with SBE-β-CD in 1:2 molar stoichiometric ratios. This inclusion complex was later incorporated into a polymer matrix to prepare an in situ gel. Various combinations of Carbopol 934P and hydroxypropyl methylcellulose (HPMC K4M) polymers were used and evaluated by rheological and in vitro drug release studies. The optimized formulation (F4) containing Carbopol 934P (0.2% w/v) and HPMC K4M (0.2% w/v) was evaluated for clarity, pH, gelling capacity, drug content, rheological properties, in vitro drug release pattern, ocular irritation test, and antimicrobial efficacy. Finally, owing to the improved antimicrobial efficacy and increased residence time, the AZM:SBE-β-CD in situ gel was found to be a promising formulation for the efficient treatment of bacterial ocular disease.

Bioavailability Improvement Strategies for Icariin and Its Derivates: A Review

In recent years, there has been considerable interest in icariin (ICA) and its derivates, icariside II (ICS) and icaritin (ICT), due to their wide range of potential applications in preventing cancer, cardiovascular disease, osteoporosis, delaying the effects of Alzheimer’s disease, treating erectile dysfunction, etc. However, their poor water solubility and membrane permeability, resulting in low bioavailability, dampens their potential beneficial effects. In this regard, several strategies have been developed, such as pharmaceutical technologies, structural transformations, and absorption enhancers. All these strategies manage to improve the bioavailability of the above-mentioned flavonoids, thus increasing their concentration in the desired places. This paper focuses on gathering the latest knowledge on strategies to improve bioavailability for enhancing the efficacy of icariin, icariside II, and icaritin. We conclude that there is an opportunity for many further improvements in this field. To the best of our knowledge, no such review articles scoping the bioavailability improvement of icariin and its derivates have been published to date. Therefore, this paper can be a good starting point for all those who want to deepen their understanding of the field.

Role of Drug Delivery System in Improving the Bioavailability of Resveratrol

Abstract:

Resveratrol (RSV) is known as a natural polyphenolic compound that is known for its therapeutic activities but has limited bioavailability. The aim of our study was to explore various drug-delivering methods that are being employed to achieve target-oriented delivery and therapeutic performance of RSV. To improve the bioavailability and pharmacokinetic properties of RSV, efforts are being made by producing efficient formulations accompanying efficient drug delivery strategies. Several clinical trial studies have been conducted on RSV isomers, and the majority of studies indicated that trans-RSV had better clinical potential and therapeutic effectiveness in various types of complications such as colorectal cancer, metabolic syndrome, hypertension, obesity, neurodegenerative diseases, diabetes, hepatic disease, cardiac disorders, and breast cancer. However, multiple research studies enable us to understand various strategies that can enhance the systemic availability and efficacy of topical RSV formulations. In this article, we emphasize the hurdles of RSV delivery processes. We summarized that for delivering liquid and solid microparticles of RSV, the micro-particulate system works efficiently. Another technique in which particles are enclosed by a coating is called microencapsulation. This technique reduces the degradation of pharmaceutical compounds. Similarly, the cyclodextrin system is mainly used for poorly soluble drugs. On the other hand, the vesicular system is another micro-particulate system that can encapsulate hydrophilic and hydrophobic drugs. However, the RSV nanosponge formulations have advanced nanodrug delivery systems also make it possible to use RSV for its antioxidant potential.

Evolving era of "sponges": Nanosponges as a versatile nanocarrier for the effective skin delivery of drugs

BACKGROUND

Nanosponge, as a carrier for skin delivery system for drugs, plays a vital role. It not only serves to administer the drug to the targeted layer of skin but also increases the drug retention and deposition on the skin.

OBJECTIVE

In this review, we aim to highlight the effects of several process and formulation variables prompting the characteristics of various nanosponges for the delivery of drugs into/ across the skin.

METHOD

In the present review article, over-all introduction of nanosponges, its preparation, characterstics features, advanatges, disadvantages, factors affecting their preparation are covered. Furthermore, an elaborative description of nanosponges for skin delivery and its toxicological perspective with some referential examples of nanosponge drugs have also been deliberated here.

RESULTS

Factors associated with the formation of nanosponges can directly or indirectly affect its efficacy in skin delivery of drugs. These nanoforms are efficient in delivering the drugs which possess lower aqueous solubility, therefore, the aqueous solubility of drugs possessing a narrow therapeutic window can easily be enhanced. It also helps in achieving targeted drug delivery, controlled release of drugs, increases bioavailability, reduces drug toxicity, decreases drug degradation, and many more.

CONCLUSION

Nanosponges have been identified as a potential drug delivery carriers into as well as across skin. Delivery of biologics such as vaccines, enzymes, peptides, proteins, and antibodies, is also gaining attention in the recent past.