The molecular assembly of the ionic liquid/aliphatic carboxylic acid/aliphatic amine as effective and safety transdermal permeation enhancers

Utilizing ionic liquids as eco-friendly and sustainable carriers for delivering nucleic acids: A review on the revolutionary advancement in nano delivery systems

Ionic liquids (ILs) are an extremely versatile class of chemicals. It has been shown that they can effectively pass through many biological barriers in the human body to deliver medications. ILs are solvents noted for their ecological friendliness; they contain equal amounts of cations and anions and remain liquid at temperatures below 100 °C. Hence, these are ideal for biomedical applications owing to their advantageous properties such as biocompatibility, solubility, and adaptability. ILs are widely reported to improve the solubility and stability of nucleic acids (DNA and RNA) in aqueous conditions, allowing for more effective delivery. Certain ILs have shown the ability to enhance the absorption of nucleic acids into cells. In addition, ILs can also be used to create vectors for gene delivery, such as liposomes and nanoparticles, thereby improving the transfection efficiency of plasmid DNA and siRNA. Subsequently, the application of ILs for nucleic acid delivery has increased significantly in recent years. In this context, we believe that using ILs to enhance the transport of nucleic acids will have a considerable effect as a novel and crucial therapeutic method in the upcoming decades. The use of ILs as solvents to preserve the natural structure of DNA and RNA shows promise for a variety of biotechnological and medical applications. Notably, ILs may be utilized for a variety of functions, including extracting, concentrating, stabilizing, and spreading nucleic acids inside cells. Our review emphasizes the key findings of research works published in this domain, wherein outstanding effectiveness of delivering RNA to the desired areas was achieved, and was made possible through the utilization of ILs.

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.

Ionic liquids as the effective technology for enhancing transdermal drug delivery: Design principles, roles, mechanisms, and future challenges

Ionic liquids (ILs) have been proven to be an effective technology for enhancing drug transdermal absorption. However, due to the unique structural components of ILs, the design of efficient ILs and elucidation of action mechanisms remain to be explored. In this review, basic design principles of ideal ILs for transdermal drug delivery system (TDDS) are discussed considering melting point, skin permeability, and toxicity, which depend on the molar ratios, types, functional groups of ions and inter-ionic interactions. Secondly, the contributions of ILs to the development of TDDS through different roles are described: as novel skin penetration enhancers for enhancing transdermal absorption of drugs; as novel solvents for improving the solubility of drugs in carriers; as novel active pharmaceutical ingredients (API-ILs) for regulating skin permeability, solubility, release, and pharmacokinetic behaviors of drugs; and as novel polymers for the development of smart medical materials. Moreover, diverse action mechanisms, mainly including the interactions among ILs, drugs, polymers, and skin components, are summarized. Finally, future challenges related to ILs are discussed, including underlying quantitative structure-activity relationships, complex interaction forces between anions, drugs, polymers and skin microenvironment, long-term stability, and in vivo safety issues. In summary, this article will promote the development of TDDS based on ILs.

Understanding the effects of targeted modifications on the 1 : 2 Choline And GEranate structure

1 : 2 Choline-and-geranate (CAGE) is an ionic liquid (IL) widely studied for its biomedical applications. However, both its industrial-scale preparation and its long-term storage are problematic so finding more suitable candidates which retain its advantageous properties is crucial. As a first step towards this we have conducted a targeted modification study to understand the effects of specific functional groups on the properties of CAGE. 1 : 2 Choline-and-octanoate and 1 : 2 butyltrimethylammonium-and-octanoate were synthesised and their thermal and rheological properties examined in comparison to those of CAGE. Using differential scanning calorimetry and polarising microscopy, the model compound was found to be an isotropic liquid, while the analogues were room-temperature liquid-crystals which transition to isotropic liquids upon heating. Dynamic mechanical analysis showed that the thermal behaviour of the studied systems was even more complex, with the ILs also undergoing a thermally-activated relaxation process. Furthermore, we have used electron paramagnetic resonance (EPR) spectroscopy, along with a variety of spin probes with different functional groups, in order to understand the chemical environment experienced by solutes in each system. The EPR spectra indicate that the radicals experience two distinct environments (polar and nonpolar) in the liquid-crystalline phase, but only one average environment in the isotropic phase. The liquid-crystalline phase experiments also showed that the relative populations of the two domains depend on the nature of the solutes, with polar or strongly hydrogen-bonding solutes preferring the polar domain. For charged solutes, the EPR spectra showed line-broadening, suggesting that their ionic nature leads to complex, unresolved interactions.

Ionic liquids and deep eutectic solvents for the stabilization of biopharmaceuticals: A review

Biopharmaceuticals have allowed the control of previously untreatable diseases. However, their low solubility and stability still hinder their application, transport, and storage. Hence, researchers have applied different compounds to preserve and enhance the delivery of biopharmaceuticals, such as ionic liquids (ILs) and deep eutectic solvents (DESs). Although the biopharmaceutical industry can employ various substances for enhancing formulations, their effect will change depending on the properties of the target biomolecule and environmental conditions. Hence, this review organized the current state-of-the-art on the application of ILs and DESs to stabilize biopharmaceuticals, considering the properties of the biomolecules, ILs, and DESs classes, concentration range, types of stability, and effect. We also provided a critical discussion regarding the potential utilization of ILs and DESs in pharmaceutical formulations, considering the restrictions in this field, as well as the advantages and drawbacks of these substances for medical applications. Overall, the most applied IL and DES classes for stabilizing biopharmaceuticals were cholinium-, imidazolium-, and ammonium-based, with cholinium ILs also employed to improve their delivery. Interestingly, dilute and concentrated ILs and DESs solutions presented similar results regarding the stabilization of biopharmaceuticals. With additional investigation, ILs and DESs have the potential to overcome current challenges in biopharmaceutical formulation.

A Comprehensive Review on Imperative Role of Ionic Liquids in Pharmaceutical Sciences

Ionic liquids (ILs) are poorly-coordinated ionic salts that can exist as a liquid at room temperatures (or <100 °C). ILs are also referred to as "designer solvents" because so many of them have been created to solve particular synthetic issues. ILs are regarded as "green solvents" because they have several distinctive qualities, including better ionic conduction, recyclability, improved solvation ability, low volatility, and thermal stability. These have been at the forefront of the most innovative fields of science and technology during the past few years. ILs may be employed in new drug formulation development and drug design in the field of pharmacy for various functions such as improvement of solubility, targeted drug delivery, stabilizer, permeability enhancer, or improvement of bioavailability in the development of pharmaceutical or vaccine dosage formulations. Ionic liquids have become a key component in various areas such as synthetic and catalytic chemistry, extraction, analytics, biotechnology, etc., due to their superior abilities along with highly modifiable potential. This study concentrates on the usage of ILs in various pharmaceutical applications enlisting their numerous purposes from the delivery of drugs to pharmaceutical synthesis. To better comprehend cuttingedge technologies in IL-based drug delivery systems, highly focused mechanistic studies regarding the synthesis/preparation of ILs and their biocompatibility along with the ecotoxicological and biological effects need to be studied. The use of IL techniques can address key issues regarding pharmaceutical preparations such as lower solubility and bioavailability which plays a key role in the lack of effectiveness of significant commercially available drugs.

Ionic Liquids: New Forms of Active Pharmaceutical Ingredients with Unique, Tunable Properties

This Review aims to summarize advances over the last 15 years in the development of active pharmaceutical ingredient ionic liquids (API-ILs), which make up a prospective game-changing strategy to overcome multiple problems with conventional solid-state drugs, for example, polymorphism. A critical part of the present Review is the collection of API-ILs and deep eutectic solvents (DESs) prepared to date. The Review covers rules for rational design of API-ILs and tools for API-IL formation, syntheses, and characterization. Nomenclature and ionic speciation, and the confusion that these may cause, are highlighted, particularly for speciation in both ILs and DESs of intermediate ionicity. We also highlight in vivo and in vitro pharmaceutical activity studies, with differences in pharmacokinetic/pharmacodynamic depending on ionicity of API-ILs. A brief overview is provided for the ILs used to deliver drugs, and the Review concludes with key prospects and roadblocks in translating API-ILs into pharmaceutical manufacturing.

Effect of Ionic Liquid on Silver-Nanoparticle-Complexed Ganoderma applanatum and Its Topical Film Formulation

Imidazolium-based ionic liquids have been widely utilized as versatile solvents for metal nanoparticle preparation. Silver nanoparticles and Ganoderma applanatum have displayed potent antimicrobial activities. This work aimed to study the effect of 1-butyl-3-methylimidazolium bromide-based ionic liquid on the silver-nanoparticle-complexed G. applanatum and its topical film. The ratio and conditions for preparation were optimized by the design of the experiments. The optimal ratio was silver nanoparticles: G. applanatum extract: ionic liquid at 97:1:2, and the conditions were 80 °C for 1 h. The prediction was corrected with a low percentage error. The optimized formula was loaded into a topical film made of polyvinyl alcohol and Eudragit^®, and its properties were evaluated. The topical film was uniform, smooth, and compact and had other desired characteristics. The topical film was able to control the release of silver-nanoparticle-complexed G. applanatum from the matrix layer. Higuchi's model was used to fit the kinetic of the release. The skin permeability of the silver-nanoparticle-complexed G. applanatum was improved by about 1.7 times by the ionic liquid, which might increase solubility. The produced film is suitable for topical applications and may be utilized in the development of potential future therapeutic agents for the treatment of diseases.

Role and Recent Advancements of Ionic Liquids in Drug Delivery Systems

Advancements in the fields of ionic liquids (ILs) broaden its applications not only in traditional use but also in different pharmaceutical and biomedical fields. Ionic liquids "Solutions for Your Success" have received a lot of interest from scientists due to a myriad of applications in the pharmaceutical industry for drug delivery systems as well as targeting different diseases. Solubility is a critical physicochemical property that determines the drug's fate at the target site. Many promising drug candidates fail in various phases of drug research due to poor solubility. In this context, ionic liquids are regarded as effective drug delivery systems for poorly soluble medicines. ILs are also able to combine different anions/cations with other cations/anions to produce salts that satisfy the concept behind the ILs. The important characteristics of ionic liquids are the modularity of their physicochemical properties depending on the application. The review highlights the recent advancement and further applications of ionic liquids to deliver drugs in the pharmaceutical and biomedical fields.

Potential for reversing miR-634-mediated cytoprotective processes to improve efficacy of chemotherapy against oral squamous cell carcinoma

For advanced oral squamous cell carcinoma (OSCC), increasing sensitivity to chemotherapy is a major challenge in improving treatment outcomes, and targeting cytoprotective processes that lead to the chemotherapy resistance of cancer cells may be therapeutically promising. Tumor-suppressive microRNAs (miRNAs) can target multiple cancer-promoting genes concurrently and are thus expected to be useful seeds for cancer therapeutics. We revealed that miR-634-mediated targeting of multiple cytoprotective process-related genes, including cellular inhibitor of apoptosis protein 1 (cIAP1), can effectively increase cisplatin (CDDP)-induced cytotoxicity and overcome CDDP resistance in OSCC cells. The combination of topical treatment with miR-634 ointment and administration of CDDP was synergistically effective against OSCC tumor growth in a xenograft mouse model. Furthermore, the expression of miR-634 target genes is frequently upregulated in primary OSCC tumors. Our study suggests that reversing miR-634-mediated cytoprotective processes activated in cancer cells is a potentially useful strategy to improve CDDP efficacy against advanced OSCC.

Preparation and characterization of innovative electrospun nanofibers loaded with pharmaceutically applicable ionic liquids

Keeping up with cutting edge research in the field of drug delivery, the overall goal of this study was to develop innovative electrospun nanofibers loaded with ionic liquids (ILs) as active pharmaceutical ingredients (APIs). For the first time, a novel approach was examined by combining biocompatible polymer, poly (ethylene oxide) (PEO), and pharmaceutical ILs in an electrospinning process to develop nanofibers with high drug loading (up to 47%). Firstly, two well-known local anaesthetic drugs, lidocaine and procaine, were modified into ILs with the salicylate, forming lidocaine salicylate and procaine salicylate. Its dual-functional nature and increased water solubility for 4- to 10-fold depending on the drug used contribute to overcoming current hurdles encountered by APIs such as poor solubility, low bioavailability, and polymorphism of the solid-state. Nanofibers were formulated using solutions tested for density, viscosity, electrical conductivity, and small-angle X-ray scattering by varying PEO molecular weight and the PEO to IL mass ratio. Scanning electron microscopy showed the surface morphology of the obtained nanofibers, while Fourier transform infrared spectroscopy and differential scanning calorimetry confirmed IL in the nanofibers in an amorphous state. Thus, nanofibers with incorporated IL represent well-known drugs in the new form and a novel dermal application delivery system.

Molecular perspective of efficiency and safety problems of chemical enhancers: bottlenecks and recent advances

Chemical penetration enhancer (CPE) is a preferred approach to improve drug permeability through the skin, due to its unique advantages of simple use and high compatibility. However, CPEs efficiency and safety problems frequently arise, which greatly restrains the further application in transdermal drug delivery systems (TDDS). To get access to the root of problems, the efficiency and safety of CPEs are reviewed especially from molecular perspectives, which include (1) the possible factors of CPEs low efficiency; (2) the possible contribution of CPEs in the evolution of safety problems such as skin irritation and allergic reaction; (3) the interactive relationship between CPEs efficiency and safety, as well as the bottlenecks of achieving their balance. More importantly, based on these, recent advances are summarized in improving efficiency or safety of CPEs, which offers a guidance of rationally selecting CPEs in future research.

Augmentation of lenvatinib efficacy by topical treatment of miR-634 ointment in anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is one of the most lethal types of human tumors. Lenvatinib can improve the disease control and prognosis in patients with ATC. However, there is an unmet need to develop a therapeutically safer and non-invasive strategy that improves the efficacy of lenvatinib for advanced ATC tumors, which grow larger close to the skin. We previously demonstrated that the topical application of an ointment incorporating tumor suppressive microRNA (TS-miR), miR-634, is a useful strategy as a TS-miR therapeutics. Here, we found that the overexpression of miR-634 synergistically increased lenvatinib-induced cytotoxicity by concurrently downregulating multiple genes related to cytoprotective processes, including ASCT2, a glutamine transporter, in ATC cell lines. Furthermore, the topical application of a miR-634 ointment on subcutaneous tumors effectively augmented the anti-tumor effects of lenvatinib in an ATC xenograft mouse model. Thus, we propose topical treatment of a miR-634 ointment as a rational strategy for improving lenvatinib-based therapy for ATC.

Ionic liquids: prospects for nucleic acid handling and delivery

Operations with nucleic acids are among the main means of studying the mechanisms of gene function and developing novel methods of molecular medicine and gene therapy. These endeavours usually imply the necessity of nucleic acid storage and delivery into eukaryotic cells. In spite of diversity of the existing dedicated techniques, all of them have their limitations. Thus, a recent notion of using ionic liquids in manipulations of nucleic acids has been attracting significant attention lately. Due to their unique physicochemical properties, in particular, their micro-structuring impact and tunability, ionic liquids are currently applied as solvents and stabilizing media in chemical synthesis, electrochemistry, biotechnology, and other areas. Here, we review the current knowledge on interactions between nucleic acids and ionic liquids and discuss potential advantages of applying the latter in delivery of the former into eukaryotic cells.

Freire CS, Silvestre AJD, Freire MG. The Role of Ionic Liquids in the Pharmaceutical Field: An Overview of Relevant Applications

Solubility, bioavailability, permeation, polymorphism, and stability concerns associated to solid-state pharmaceuticals demand for effective solutions. To overcome some of these drawbacks, ionic liquids (ILs) have been investigated as solvents, reagents, and anti-solvents in the synthesis and crystallization of active pharmaceutical ingredients (APIs), as solvents, co-solvents and emulsifiers in drug formulations, as pharmaceuticals (API-ILs) aiming liquid therapeutics, and in the development and/or improvement of drug-delivery-based systems. The present review focuses on the use of ILs in the pharmaceutical field, covering their multiple applications from pharmaceutical synthesis to drug delivery. The most relevant research conducted up to date is presented and discussed, together with a critical analysis of the most significant IL-based strategies in order to improve the performance of therapeutics and drug delivery systems.

Improving the Efficacy of EGFR Inhibitors by Topical Treatment of Cutaneous Squamous Cell Carcinoma with miR-634 Ointment

For cutaneous squamous cell carcinoma (cSCC), topical treatment is an essential option for patients who are not candidates for, or who refuse, surgery. Epidermal growth factor receptor (EGFR) plays a key role in the development of cSCC, but EGFR tyrosine kinase inhibitors (TKIs), such as gefitinib, have shown only partial clinical benefit in this disease. Thus, there is an unmet need to develop novel strategies for improving the efficacy of TKIs in cSCC. We previously demonstrated that the tumor-suppressive microRNA (miRNA) miR-634 functions as a negative modulator of the cytoprotective cancer cell survival processes and is a useful anticancer therapeutic agent. In the present study, we found that topical application of an ointment containing miR-634 inhibited in vivo tumor growth without toxicity in a cSCC xenograft mouse model and a 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced papilloma mouse model. Functional validation revealed that miR-634 overexpression reduced glutaminolysis by directly targeting ASCT2, a glutamine transporter. Furthermore, overexpression of miR-634 synergistically enhanced TKI-induced cytotoxicity by triggering severe energetic stress in vitro and in vivo. Thus, we propose that topical treatment with miR-634 ointment is a useful strategy for improving for EGFR TKI-based therapy for cSCC.

Transdermal delivery of nobiletin using ionic liquids

Nobiletin (NOB), a flavonoid, has extremely low water solubility and low oral bioavailability; however, despite these problems, various physiological effects have been investigated in vitro. In the present study, we investigated the transdermal delivery of NOB using choline and geranic acid (CAGE), which is a biocompatible material that has been reported to be a promising transdermal delivery approach. The feasibility was evaluated by a set of in vitro and in vivo tests. A solubility evaluation demonstrated that CAGE induced excellent solubility of NOB induced by multipoint hydrogen bonding between NOB and CAGE. In vitro transdermal tests using a Franz diffusion cell showed that CAGE was effective in enhancing transdermal absorption of NOB, compared to other penetration enhancers. Subsequent in vivo tests demonstrated that CAGE significantly improved area under the concentration-time curve of NOB in vivo and NOB/CAGE sample showed 20-times higher bioavailability than oral administration of NOB crystal. Furthermore, NOB/CAGE sample also showed significant drops of the blood glucose level in rats derived from hypoglycemic activity of NOB. Thus, transdermal administration of NOB using CAGE was shown to be feasible, which indicates that the use of CAGE may be adapted for other flavonoids that also show both low water solubility and low permeability.

Ionic liquids: green and tailor-made solvents in drug delivery

Beyond their traditional use as green solvents, new applications have become available for ionic liquids (ILs) in drug delivery. Their flexible tunability enables task-specific optimization of ILs at molecular level. Thus, ILs have been exploited to improve the solubility and permeability of drugs and relieve the polymorphic problems associated with crystalline active pharmaceutical ingredients (APIs). Controlled preparation of drug nanocarriers are also achieved by using ILs either as media or as functional agents. Here, we highlight the importance and advantages of ILs in pharmaceutics and look towards the future of IL-based drug delivery.

Ionic liquid-based transdermal delivery of propranolol: a patent evaluation of US2018/0169033A1

Ionic liquids (ILs) are organic salts of asymmetric organic cations and inorganic/organic anions and are considered green alternative to organic solvents. ILs have high thermal stability, low volatility, low toxicity and high biodegradability. ILs are frequently used for enhancing the solubility and stability of active pharmaceutical ingredients. This study describes an invention related to the preparation of amorphous melts of propranolol incorporated into transdermal patches for infantile hemangioma intervention. Reduction in skin irritation and a significant increase in transdermal permeability of propranolol from its amorphous melts was reported. However, toxicity and stability issues of the IL-based active pharmaceutical ingredients and their drug delivery systems are yet to be established from regulatory perspective before exploiting commercial viability of these forms.

Ionic Liquid-Polymer Nanoparticle Hybrid Systems as New Tools to Deliver Poorly Soluble Drugs

The use of functional excipients such as ionic liquids (ILs) and the encapsulation of drugs into nanocarriers are useful strategies to overcome poor drug solubility. The aim of this work was to evaluate the potential of IL-polymer nanoparticle hybrid systems as tools to deliver poorly soluble drugs. These systems were obtained using a methodology previously developed by our group and improved herein to produce IL-polymer nanoparticle hybrid systems. Two different choline-based ILs and poly (lactic-co-glycolic acid) (PLGA) 50:50 or PLGA 75:25 were used to load rutin into the delivery system. The resulting rutin-loaded IL-polymer nanoparticle hybrid systems presented a diameter of 250-300 nm, with a low polydispersity index and a zeta potential of about -40 mV. The drug association efficiency ranged from 51% to 76%, which represents a good achievement considering the poor solubility of rutin. No significant particle aggregation was obtained upon freeze-drying. The presence of the IL in the nanosystem does not affect its sustained release properties, achieving about 85% of rutin released after 72 h. The cytotoxicity studies showed that the delivery system was not toxic to HaCat cells. Our findings may open a new paradigm on the therapy improvement of diseases treated with poorly soluble drugs.

Synthesis, characterization, ecotoxicity and biodegradability evaluations of novel biocompatible surface active lauroyl sarcosinate ionic liquids

Ionic liquids (ILs) based surfactants have been emerged as attractive alternatives to the conventional surfactants owing to their tailor-made and eco-friendly properties. Therefore, present study described the synthesis of nine new fatty amino acids based IL surfactants utilizing lauroyl sarcosinate anion and pyrrolidinium, imidazolium, pyridinium, piperidinium, morpholinium and cholinium cations for the first time. The synthesized surface active lauroyl sarcosinate ionic liquids (SALSILs) were characterized by ¹H NMR, ¹³C NMR and TGA. Next, the surface tension and critical micellar concentrations were determined and compared with the surface properties of ILs based surfactants. Further, the toxicity and biodegradability of the synthesized SALSIILs were evaluated to confirm their safe and efficient process applications. The studies revealed that three out of nine synthesized SALSILs containing pyridinium cation have showed strong activity towards the tested microbial growth. The remaining six SALSILs met the biocompatible measures demonstrating moderate to low activity depends on the tested microbes. The alicyclic SALSILs containing morpholinium and piperidinium cations have demonstrated 100% biodegradation after 28 days of the test period. Overall, it is believed that the synthesized SALSILs could effectively replace the conventional surfactants in a wide variety of applications.

Design Principles of Ionic Liquids for Transdermal Drug Delivery

Ionic liquids (ILs) and deep eutectic solvents have shown great promise in drug delivery applications. Choline-based ILs, in particular choline and geranic acid (CAGE), have been used to enhance the transdermal delivery of several small and large molecules. However, detailed studies outlining the design principles of ILs for transdermal drug delivery are still lacking. Using two model drugs of differing hydrophilicities, acarbose and ruxolitinib and 16 ILs, the dependence of skin penetration on the chemical properties of ILs is examined. First, the impact of ion stoichiometry on skin penetration of drugs is assessed using CAGE, which evidences that a molar ratio of 1:2 of choline to geranic acid yields the highest delivery. Subsequently, variants of CAGE are prepared using anions with structural similarity to geranic acid and cations with structural similarity to choline at a ratio of 1:2. Mechanistic studies reveal that the potency of ILs in enhancing transdermal drug delivery correlates inversely with the inter-ionic interactions as determined by 2D NMR spectroscopy. Using this understanding, a new IL is designed, and it provides the highest delivery of ruxolitinib of all ILs tested here. Overall, these studies provide a generalized framework for optimizing ILs for enhancing skin permeability.

Ionic Liquids as Potential and Synergistic Permeation Enhancers for Transdermal Drug Delivery

Transdermal drug delivery systems (TDDS) show clear advantages over conventional routes of drug administration. Nonetheless, there are limitations to current TDDS which warrant further research to improve current TDD platforms. Spurred by the synthesis of novel biodegradable ionic liquids (ILs) and favorable cytotoxicity studies, ILs were shown to be a possible solution to overcome these challenges. Their favorable application in overcoming challenges ranging from synthesis, manufacture, and even therapeutic benefits were documented. In this review, said ILs are highlighted and their role in TDDS is reviewed in terms of (a) ILs as permeation enhancers (single agents or combined), (b) ILs in drug modification, and (c) ILs as active pharmaceutical ingredients. Furthermore, future combination of ILs with other chemical permeation enhancers (CPEs) is proposed and discussed.

An emerging integration between ionic liquids and nanotechnology: general uses and future prospects in drug delivery

There is a growing need to develop drug-delivery systems that overcome drawbacks such as poor drug solubility/loading/release, systemic side effects and limited stability. Ionic liquids (ILs) offer many advantages and their tailoring represents a valuable tuning tool. Nano-based systems are also prized materials that prevent drug degradation, enhance their transport/distribution and extend their release. Consequently, structures containing ILs and nanoparticles (NPs) have been developed to attain synergistic effects. This overview on the properties of ILs, NPs and of their combined structures, reveals the recent advances in these areas through a review of pertinent literature. The IL-NP structures present enhanced properties and the subsequent performance upgrade proves to be useful in drug delivery, although much is yet to be done.

Evaluation of anionic surfactants effects on the skin barrier function based on skin permeability

Anionic surfactants are often used for cleaning and pharmaceutical purposes because of their strong surfactancy and foaming property. However, they are rarely ingested orally, the skin is a part of the human body most affected by surfactants. Barrier function of the skin is very strong, but the anionic surfactants can cause serious damages to it. Recently, amino acid-based surfactants have attracted attention as a safer option owing to their biocompatibility. Cytotoxicity examinations revealed that the amino acid-based surfactants are superior to sulfate-based surfactants. However, a systematical and comprehensive study related to the effect of these surfactants on skin barrier function has not yet been reported. In this work, skin permeation test using the skin of hairless mice and HPLC method is carried out. The material transmission speed through skin in a steady state was different between each surfactant treatment. We performed a comprehensive analysis of the effect of surfactants on skin barrier function and defined Transmission Index as an index for the degree of effect of surfactants. Glutamate series amino acid-based surfactant were effective to Transmission Index and we guessed the cause was due to adsorption. Based on the finding this study, we suggest using adsorptive property as a measure to the effect on the skin barrier function.

Ionic liquids for addressing unmet needs in healthcare

Advances in the field of ionic liquids have opened new applications beyond their traditional use as solvents into other fields especially healthcare. The broad chemical space, rich with structurally diverse ions, and coupled with the flexibility to form complementary ion pairs enables task-specific optimization at the molecular level to design ionic liquids for envisioned functions. Consequently, ionic liquids now are tailored as innovative solutions to address many problems in medicine. To date, ionic liquids have been designed to promote dissolution of poorly soluble drugs and disrupt physiological barriers to transport drugs to targeted sites. Also, their antimicrobial activity has been demonstrated and could be exploited to prevent and treat infectious diseases. Metal-containing ionic liquids have also been designed and offer unique features due to incorporation of metals. Here, we review application-driven investigations of ionic liquids in medicine with respect to current status and future potential.

Influence of bile salt on vitamin E derived vesicles involving a surface active ionic liquid and conventional cationic micelle

This study has been actually performed with the aim to develop vitamin E derived vesicles individually from a surface active ionic liquid (1-Hexadecyl-3-Methylimidazolium chloride ([C₁₆mim]Cl)) and a common cationic amphiphile (benzyldimethylhexadecylammonium chloride (BHDC)) and also to investigate their consequent breakdown in presence of bile salt molecule. From this study, it is revealed that the rotational motion of coumarin 153 (C153) molecule is hindered as the vitamin E content is increased in the individual micellar solution of [C₁₆mim]Cl and BHDC. The extent of enhancement in rotational relaxation time is more pronounced in case of [C₁₆mim]Cl-vitamin E solutions than in the BHDC-vitamin E vesicular aggregates which confirms the greater rigidity of the former vesicular system than the later one. Moreover, the effect of bile salt in the vitamin E forming vesicular assemblies have also been unravelled. It is found that the large area occupancy by the steroidal backbone of the bile salt plays a crucial role towards the enlargement of the average surfactant head group area. This results in disintegration of the vesicles composed of vitamin E and consequently, vesicles are transformed into mixed micellar aggregates. From the anisotropy measurement it is found that the rotational motion of C153 is more hindered in the [C₁₆mim]Cl/BHDC-NaCh mixed micelles compared to that inside the individual vesicles. The fluorescence correlation spectroscopic (FCS) study also confirms that the mixed micelles have a more compact structure than that of the [C₁₆mim]Cl-vitamin E and BHDC-vitamin E vesicles. Altogether, the micelle to vesicle transition involving any vitamin and their disruption by bile salt would be an interesting investigation both from the view point of basic colloidal chemistry and towards the generation of new drug delivery vehicle due to their unique microenvironment. Therefore, in future, these systems can be utilised as vehicle for the transport and as well as delivery of drugs and as probable reactor in nanomaterial synthesis.

Hydroxycinnamic Acids and Their Derivatives: Cosmeceutical Significance, Challenges and Future Perspectives, a Review

Bioactive compounds from natural sources, due to their widely-recognized benefits, have been exploited as cosmeceutical ingredients. Among them, phenolic acids emerge with a very interesting potential. In this context, this review analyzes hydroxycinnamic acids and their derivatives as multifunctional ingredients for topical application, as well as the limitations associated with their use in cosmetic formulations. Hydroxycinnamic acids and their derivatives display antioxidant, anti-collagenase, anti-inflammatory, antimicrobial and anti-tyrosinase activities, as well as ultraviolet (UV) protective effects, suggesting that they can be exploited as anti-aging and anti-inflammatory agents, preservatives and hyperpigmentation-correcting ingredients. Due to their poor stability, easy degradation and oxidation, microencapsulation techniques have been employed for topical application, preventing them from degradation and enabling a sustained release. Based on the above findings, hydroxycinnamic acids present high cosmetic potential, but studies addressing the validation of their benefits in cosmetic formulations are still scarce. Furthermore, studies dealing with skin permeation are scarcely available and need to be conducted in order to predict the topical bioavailability of these compounds after application.

Biological Activity of Ionic Liquids and Their Application in Pharmaceutics and Medicine

Ionic liquids are remarkable chemical compounds, which find applications in many areas of modern science. Because of their highly tunable nature and exceptional properties, ionic liquids have become essential players in the fields of synthesis and catalysis, extraction, electrochemistry, analytics, biotechnology, etc. Apart from physical and chemical features of ionic liquids, their high biological activity has been attracting significant attention from biochemists, ecologists, and medical scientists. This Review is dedicated to biological activities of ionic liquids, with a special emphasis on their potential employment in pharmaceutics and medicine. The accumulated data on the biological activity of ionic liquids, including their antimicrobial and cytotoxic properties, are discussed in view of possible applications in drug synthesis and drug delivery systems. Dedicated attention is given to a novel active pharmaceutical ingredient-ionic liquid (API-IL) concept, which suggests using traditional drugs in the form of ionic liquid species. The main aim of this Review is to attract a broad audience of chemical, biological, and medical scientists to study advantages of ionic liquid pharmaceutics. Overall, the discussed data highlight the importance of the research direction defined as "Ioliomics", studies of ions in liquids in modern chemistry, biology, and medicine.