Design and characterization of ascorbic acid based therapeutic deep eutectic solvent as a new ion-gel for delivery of sunitinib malate

Applications of Functional Polymeric Eutectogels

Over the past two decades, deep eutectic solvents (DESs) have captured significant attention as an emergent class of solvents that have unique properties and applications in differing fields of chemistry. One area where DES systems find utility is the design of polymeric gels, often referred to as "eutectogels," which can be prepared either using a DES to replace a traditional solvent, or where monomers form part of the DES themselves. Due to the extensive network of intramolecular interactions (e.g., hydrogen bonding) and ionic species that exist in DES systems, polymeric eutectogels often possess appealing material properties-high adhesive strength, tuneable viscosity, rapid polymerization kinetics, good conductivity, as well as high strength and flexibility. In addition, non-covalent crosslinking approaches are possible due to the inherent interactions that exist in these materials. This review considers several key applications of polymeric eutectogels, including organic electronics, wearable sensor technologies, 3D printing resins, adhesives, and a range of various biomedical applications. The design, synthesis, and properties of these eutectogels are discussed, in addition to the advantages of this synthetic approach in comparison to traditional gel design. Perspectives on the future directions of this field are also highlighted.

Oral delivery of Sunitinib malate using carboxymethyl cellulose/poly(acrylic acid-itaconic acid)/Cloisite 30B nanocomposite hydrogel as a pH-responsive carrier

This work aimed to fabricate a Cloisite 30B-incorporated carboxymethyl cellulose graft copolymer of acrylic acid and itaconic acid hydrogel (Hyd) via a free radical polymerization method for controlled release of Sunitinib malate anticancer drug. The synthesized samples were characterized by FTIR, XRD, TEM, and SEM-dot mapping analyses. The encapsulation efficiency of Hyd and Hyd/Cloisite 30B (6 wt%) was 81 and 93%, respectively, showing the effectiveness of Cloisite 30B in drug loading. An in vitro drug release study showed that drug release from all samples in a buffer solution with pH 7.4 was higher than in a buffer solution with pH 5.5. During 240 min, the cumulative drug release from Hyd/Cloisite 30B (94.97% at pH 7.4) is lower than Hyd (53.71% at pH 7.4). Also, drug-loaded Hyd/Cloisite 30B (6 wt%) demonstrated better antibacterial activity towards S. Aureus bacteria and E. Coli. High anticancer activity of Hyd/Cloisite 30B against MCF-7 human breast cancer cells was shown by the MTT assay, with a MCF-7 cell viability of 23.82 ± 1.23% after 72-hour incubation. Our results suggest that Hyd/Cloisite 30B could be used as a pH-controlled carrier to deliver anticancer Sunitinib malate.

Supramolecular eutectogel as new oral paediatric delivery system to enhance benznidazole bioavailability

Benznidazole (BNZ) serves as the primary drug for treating Chagas Disease and is listed in the WHO Model List of Essential Medicines for Children. Herein, a new child-friendly oral BNZ delivery platform is developed in the form of supramolecular eutectogels (EGs). EGs address BNZ's poor oral bioavailability and provide a flexible twice-daily dose in stick-pack format. This green and sustainable formulation strategy relies on the gelation of drug-loaded Natural Deep Eutectic Solvents (NaDES) with xanthan gum (XG) and water. Specifically, choline chloride-based NaDES form stable and biocompatible 5 mg/mL BNZ-loaded EGs. Rheological and Low-field NMR investigations indicate that EGs are viscoelastic materials comprised of two co-existing regions in the XG network generated by different crosslink distributions between the biopolymer, NaDES and water. Remarkably, the shear modulus and relaxation spectrum of EGs remain unaffected by temperature variations. Upon dilution with simulated gastrointestinal fluids, EGs results in BNZ supersaturation, serving as the primary driving force for its absorption. Interestingly, after oral administration of EGs to rats, drug bioavailability increases by 2.6-fold, with a similar increase detected in their cerebrospinal fluid. The noteworthy correlation between in vivo results and in vitro release profiles confirms the efficacy of EGs in enhancing both peripheral and central BNZ oral bioavailability.

Overview and thermodynamic modelling of deep eutectic solvents as co-solvents to enhance drug solubilities in water

The poor water solubility of active pharmaceutical ingredients (APIs) is a major challenge in the pharmaceutical industry. Co-solvents are sometimes added to enhance drug dissolution. A novel group of co-solvents, the Deep Eutectic Solvents (DES), have gained interest in the pharmaceutical field due to their good solvent power, biodegradability, sustainability, non-toxicity, and low cost. In this study, we first provide an overview of all the literature solubility studies involving a drug or API + water + DES, which can be a valuable list to some researchers. Then, we analyze these systems with focus on each individual drug/API and provide statistical information on each. A similar analysis is carried out with focus on the individual DESs. An investigation of the numeric values of the water-solubility enhancement by the different DESs for various drugs indicates that DESs are indeed effective co-solvents, with varying degrees of solubility enhancement, even up to 15-fold. This is strongly encouraging, indicating the need for further studies to find the most promising DESs for solubility enhancement. However, time-consuming and costly trial and error should be prevented by first screening, using theoretical-based or thermodynamic-based models. Based on this conclusion, the second part of the study is concerned with investigating and suggesting accurate thermodynamic approaches to tackle the phase equilibrium modeling of such systems. For this purpose, a large data bank was collected, consisting of 2009 solubility data of 25 different drugs/APIs mixed with water and 31 different DESs as co-solvents at various DES concentrations, over wide ranges of temperatures at atmospheric pressure. This data bank includes 107 DES + water + drug/API systems in total. The solubility data were then modeled according to the solid-liquid equilibrium framework, using the local composition activity coefficient models of NRTL, and UNIQUAC. The results showed acceptable behavior with respect to the experimental values and trends for all of the investigated systems, with AARD% values of 9.65 % and 14.08 % for the NRTL and UNIQUAC models, respectively. In general, the lower errors of NRTL, as well as its simpler calculation process and the requirement of fewer component parameters, suggest the priority of NRTL over UNIQUAC for use in this field.

Indole Antitumor Agents in Nanotechnology Formulations: An Overview

The indole heterocycle represents one of the most important scaffolds in medicinal chemistry and is shared among a number of drugs clinically used in different therapeutic areas. Due to its varied biological activities, high unique chemical properties and significant pharmacological behaviors, indole derivatives have drawn considerable interest in the last decade as antitumor agents active against different types of cancers. The research of novel antiproliferative drugs endowed with enhanced efficacy and reduced toxicity led to the approval by U.S. Food and Drug Administration of the indole-based anticancer agents Sunitinib, Nintedanib, Osimertinib, Panobinostat, Alectinib and Anlotinib. Additionally, new drug delivery systems have been developed to protect the active principle from degradation and to direct the drug to the specific site for clinical use, thus reducing its toxicity. In the present work is an updated review of the recently approved indole-based anti-cancer agents and the nanotechnology systems developed for their delivery.

Ionogels: recent advances in design, material properties and emerging biomedical applications

Ionic liquid (IL)-based gels (ionogels) have received considerable attention due to their unique advantages in ionic conductivity and their biphasic liquid-solid phase property. In ionogels, the negligibly volatile ionic liquid is retained in the interconnected 3D pore structure. On the basis of these physical features as well as the chemical properties of well-chosen ILs, there is emerging interest in the anti-bacterial and biocompatibility aspects. In this review, the recent achievements of ionogels for biomedical applications are summarized and discussed. Following a brief introduction of the various types of ILs and their key physicochemical and biological properties, the design strategies and fabrication methods of ionogels are presented by means of different confining networks. These sophisticated ionogels with diverse functions, aimed at biomedical applications, are further classified into several active domains, including wearable strain sensors, therapeutic delivery systems, wound healing and biochemical detections. Finally, the challenges and possible strategies for the design of future ionogels by integrating materials science with a biological interface are proposed.

Current Development of Chemical Penetration Enhancers for Transdermal Insulin Delivery

The use of the transdermal delivery system has recently gained ample recognition due to the ability to deliver drug molecules across the skin membrane, serving as an alternative to conventional oral or injectable routes. Subcutaneous insulin injection is the mainstay treatment for diabetes mellitus which often leads to non-compliance among patients, especially in younger patients. Apart from its invasiveness, the long-term consequences of insulin injection cause the development of physical trauma, which includes lipohypertrophy at the site of administration, scarring, infection, and sometimes nerve damage. Hence, there is a quest for a better alternative to drug delivery that is non-invasive and easily adaptable. One of the potential solutions is the transdermal delivery method. However, the stratum corneum (the top layer of skin) is the greatest barrier in transporting large molecules like insulin. Therefore, various chemical enhancers have been proposed to promote stratum corneum permeability, or they are designed to increase the permeability of the full epidermis, such as the use of ionic liquid, peptides, chemical pre-treatment as well as packaging insulin with carriers or nanoparticles. In this review, the recent progress in the development of chemical enhancers for transdermal insulin delivery is discussed along with the possible mechanistic of action and the potential outlook on the proposed permeation approaches in comparison to other therapeutical drugs

Polyphenol Iongel Patches with Antimicrobial, Antioxidant and Anti-Inflammatory Properties

There is an actual need for developing materials for wound healing applications with anti-inflammatory, antioxidant, or antibacterial properties in order to improve the healing performance. In this work, we report the preparation and characterization of soft and bioactive iongel materials for patches, based on polymeric poly(vinyl alcohol) (PVA) and four ionic liquids containing the cholinium cation and different phenolic acid anions, namely cholinium salicylate ([Ch][Sal]), cholinium gallate ([Ch][Ga]), cholinium vanillate ([Ch][Van]), and cholinium caffeate ([Ch][Caff]). Within the iongels, the phenolic motif in the ionic liquids plays a dual role, acting as a PVA crosslinker and a bioactive compound. The obtained iongels are flexible, elastic, ionic conducting, and thermoreversible materials. Moreover, the iongels demonstrated high biocompatibility, non-hemolytic activity, and non-agglutination in mice blood, which are key-sought material specifications in wound healing applications. All the iongels have shown antibacterial properties, being PVA-[Ch][Sal], the one with higher inhibition halo for Escherichia Coli. The iongels also revealed high values of antioxidant activity due to the presence of the polyphenol, with the PVA-[Ch][Van] iongel having the highest activity. Finally, the iongels show a decrease in NO production in LPS-stimulated macrophages, with the PVA-[Ch][Sal] iongel displaying the best anti-inflammatory activity (>63% at 200 µg/mL).

Targeted Delivery of Sunitinib by MUC-1 Aptamer-Capped Magnetic Mesoporous Silica Nanoparticles

Magnetic mesoporous silica nanoparticles (MMSNPs) are being widely investigated as multifunctional novel drug delivery systems (DDSs) and play an important role in targeted therapy. Here, magnetic cores were synthesized using the thermal decomposition method. Further, to improve the biocompatibility and pharmacokinetic behavior, mesoporous silica was synthesized using the sol-gel process to coat the magnetic cores. Subsequently, sunitinib (SUN) was loaded into the MMSNPs, and the particles were armed with amine-modified mucin 1 (MUC-1) aptamers. The MMSNPs were characterized using FT-IR, TEM, SEM, electrophoresis gel, DLS, and EDX. MTT assay, flow cytometry analysis, ROS assessment, and mitochondrial membrane potential analysis evaluated the nanoparticles' biological impacts. The physicochemical analysis revealed that the engineered MMSNPs have a smooth surface and spherical shape with an average size of 97.6 nm. The biological in vitro analysis confirmed the highest impacts of the targeted MMSNPs in MUC-1 overexpressing cells (OVCAR-3) compared to the MUC-1 negative MDA-MB-231 cells. In conclusion, the synthesized MMSNP-SUN-MUC-1 nanosystem serves as a unique multifunctional targeted delivery system to combat the MUC-1 overexpressing ovarian cancer cells.

Deep Eutectic Solvent as Green Solvent in Extraction of Biological Macromolecules: A Review

Greater awareness of environmental sustainability has driven many industries to transition from using synthetic organic solvents to greener solvents in their manufacturing. Deep eutectic solvents (DESs) have emerged as a highly promising category of green solvents with well-demonstrated and wide-ranging applications, including their use as a solvent in extraction of small-molecule bioactive compounds for food and pharmaceutical applications. The use of DES as an extraction solvent of biological macromolecules, on the other hand, has not been as extensively studied. Thereby, the feasibility of employing DES for biomacromolecule extraction has not been well elucidated. To bridge this gap, this review provides an overview of DES with an emphasis on its unique physicochemical properties that make it an attractive green solvent (e.g., non-toxicity, biodegradability, ease of preparation, renewable, tailorable properties). Recent advances in DES extraction of three classes of biomacromolecules-i.e., proteins, carbohydrates, and lipids-were discussed and future research needs were identified. The importance of DES's properties-particularly its viscosity, polarity, molar ratio of DES components, and water addition-on the DES extraction's performance were discussed. Not unlike the findings from DES extraction of bioactive small molecules, DES extraction of biomacromolecules was concluded to be generally superior to extraction using synthetic organic solvents.

Solids Turn into Liquids—Liquid Eutectic Systems of Pharmaceutics to Improve Drug Solubility

The low solubility of active pharmaceutical ingredients (APIs) is a problem in pharmaceutical development. Several methodologies can be used to improve API solubility, including the use of eutectic systems in which one of the constituents is the API. This class of compounds is commonly called Therapeutic Deep Eutectic Systems (THEDES). THEDES has been gaining attention due to their properties such as non-toxicity, biodegradability, and being non-expensive and easy to prepare. Since the knowledge of the solid liquid diagram of the mixture and the ideal eutectic point is necessary to ascertain if a mixture is a deep eutectic or just a eutectic mixture that is liquid at ambient temperature, the systems studied in this work are called Therapeutic Liquid Eutectic Systems (THELES). Therefore, the strategy proposed in this work is to improve the solubility of chlorpropamide and tolbutamide by preparing THELES. Both APIs are sulfonylurea compounds used for the treatment of type 2 diabetes mellitus and have low solubility in water. To prepare the THELES, several coformers were tested, namely, tromethamine, L(+)-arginine, L-tryptophan, citric acid, malic acid, ascorbic acid, and p-aminobenzoic acid, in molar ratios of 1:1 and 1:2. To improve viscosity, water was added in different molar ratios to all systems. THELES were characterized by mid-infrared spectroscopy (MIR), and differential scanning calorimetry. Their viscosity, solubility, and permeability were also determined. Their stability at room temperature and 40 °C was accessed by MIR. Cytocompatibility was performed by metabolic activity and cell lysis evaluation, according to ISO10993-5:2009, and compared with the crystalline APIs. THELES with TRIS were successfully synthesized for both APIs. Results showed an increased solubility without a decrease in the permeability of the APIs in the THELES when compared with the pure APIs. The THELES were also considered stable for 8 weeks at ambient temperature. The cells studied showed that the THELES were not toxic for the cell lines used.