Topical drug delivery systems: a patent review

Comprehensive Insight into Cutaneous Application of Hemp

Known for its natural bio-compounds and therapeutic properties, hemp is being utilized in the development of skin products. These products offer a wide range of applications and benefits in the fields of natural bio-compounds, pharmaceutical technology, topical delivery systems, and cosmeceuticals. This manuscript deals with hemp actives, such as cannabinoids, terpenes, and flavonoids, and their diverse biological properties relative to topical application, including anti-inflammatory, antimicrobial, and antioxidant effects. Also, the paper reviews strategies to overcome poor penetration of hemp actives, as well as the integration of hemp actives in cosmeceuticals that provide natural and sustainable alternatives to traditional skincare products offering a range of benefits, including anti-aging, moisturizing, and soothing properties. The review aims to provide a comprehensive understanding of the development and manufacturing processes of skin products containing hemp actives. By delving into the science behind hemp-based products, the paper provides valuable insights into the potential of hemp as a versatile ingredient in the pharmaceutical and cosmetic industries. The utilization of hemp in these innovative products not only offers therapeutic benefits but also promotes natural and sustainable approaches to skincare.

Revolutionizing transdermal drug delivery: unveiling the potential of cubosomes and ethosomes

The area of drug delivery systems has witnessed significant advancements in recent years, with a particular focus on improving efficacy, stability, and patient compliance. Transdermal drug delivery offers numerous benefits compared to conventional methods of drug administration through the skin. It helps in avoiding gastric irritation, hepatic first-pass metabolism, and gastric degradation of the drug. It bypasses the gastrointestinal tract, eliminating the risk of first-pass metabolism and allowing drugs to be administered without being affected by pH, enzymes, or intestinal bacteria. Additionally, it allows for sustained release of the drug, is noninvasive, and enhances patient adherence to the treatment regimen. The transdermal drug delivery system (TDDS) can serve as an alternative route for drug administration in individuals who cannot tolerate oral medications, experience nausea, or are unconscious. When compared to intravenous, hypodermic, and other parenteral routes, TDDS stands out due to its ability to eliminate pain, reduce the risk of infection, and prevent disease transmission associated with needle reuse. Consequently, the overall patient compliance is significantly improved with the utilization of TDDS. Among the noteworthy developments are cubosomes and ethosomes, two distinct yet promising carriers that have garnered attention for their unique properties. In conclusion, this review synthesizes the current knowledge on cubosomes and ethosomes, shedding light on their individual strengths and potential synergies. The exploration of their application in various therapeutic areas underscores their versatility and establishes them as key players in the evolving landscape of drug delivery systems.

Preparation and Characterization of Ferulic Acid Hydrogel and Its Application as a Local Drug Delivery Agent in Periodontitis

Introduction Periodontitis, a persistent inflammatory condition, impacts the tissues supporting teeth. Beyond mechanically eradicating the biofilm, additional host-modulating agents can aid in the treatment of periodontitis. Among these, gels are a very popular choice for use in the field of dentistry as these systems boast high biocompatibility and bioadhesiveness. These qualities make them easily administered and fabricated. They are typically placed into the periodontal site via wide-port needle syringes. Many investigations have demonstrated that hydrogels possess the ability for controlled drug release and aid in periodontal wound healing. Hence, this study aimed to develop a ferulic acid hydrogel and assess its effectiveness for managing periodontitis. Materials and methods Ferulic acid hydrogel was prepared followed by haemolysis assay and biocompatibility assay. After the in vitro analysis, a clinical trial was conducted: 20 patients were divided into Group A (comprising patients in whom scaling and root planing (SRP) was done) and Group B (comprising patients in whom SRP along with hydrogel application was done). Each patient's pocket depth (PD), clinical attachment loss (CAL), gingival index (GI), and plaque index (PI) were recorded at baseline and at three months. Intergroup and intragroup comparisons of the parameters were made. Results Ferulic acid hydrogels exhibit a minimal ratio of red blood cell destruction, indicating their low haemolytic activity. Beyond 94 hours, ferulic acid hydrogel demonstrates minimal toxicity towards human fibroblasts, suggesting it has good biocompatibility. When clinical parameters were compared after three months of treatment with SRP alone, significant reductions were observed in all parameters. However, when hydrogel application was done along with SRP, greater reduction was seen in terms of all clinical parameters indicating the efficacy of the ferulic acid hydrogel as an adjunct.  Conclusion Ferulic acid has distinct haemolytic activity as well as good biocompatibility. Its use also led to a considerable reduction in all clinical parameters, necessitating its role as a local drug delivery agent in the treatment of periodontitis.

Enhancing the Topical Antibacterial Activity of Fusidic Acid via Embedding into Cinnamon Oil Nano-Lipid Carrier

Presently, antimicrobial resistance is of great risk to remarkable improvements in health conditions and infection management. Resistance to various antibiotics has been considered a great obstacle in their usage, necessitating alternative strategies for enhancing the antibacterial effect. Combination therapy has been recognized as a considerable strategy that could improve the therapeutic influence of antibacterial agents. Therefore, the aim of this study was to combine the antibacterial action of compounds of natural origin like fusidic acid (FA) and cinnamon essential oil (CEO) for synergistic effects. A distinctive nanoemulsion (NE) was developed using cinnamon oil loaded with FA. Applying the Box-Behnken design (BBD) approach, one optimized formula was selected and integrated into a gel base to provide an FA-NE-hydrogel for optimal topical application. The FA-NE-hydrogel was examined physically, studied for in vitro release, and investigated for stability upon storage at different conditions, at room (25 °C) and refrigerator (4 °C) temperatures, for up to 3 months. Ultimately, the NE-hydrogel preparation was inspected for its antibacterial behavior using multidrug-resistant bacteria and checked by scanning electron microscopy. The FA-NE-hydrogel formulation demonstrated a pH (6.32), viscosity (12,680 cP), and spreadability (56.7 mm) that are acceptable for topical application. The in vitro release could be extended for 6 h, providing 52.0%. The formulation was stable under both test conditions for up to 3 months of storage. Finally, the FA-NE-hydrogel was found to inhibit the bacterial growth of not only Gram-positive but also Gram-negative bacteria. The inhibition was further elucidated by a scanning electron micrograph, indicating the efficiency of CEO in enhancing the antibacterial influence of FA when combined in an NE system.

Advances in Hydrogel-Based Drug Delivery Systems

Hydrogels, with their distinctive three-dimensional networks of hydrophilic polymers, drive innovations across various biomedical applications. The ability of hydrogels to absorb and retain significant volumes of water, coupled with their structural integrity and responsiveness to environmental stimuli, renders them ideal for drug delivery, tissue engineering, and wound healing. This review delves into the classification of hydrogels based on cross-linking methods, providing insights into their synthesis, properties, and applications. We further discuss the recent advancements in hydrogel-based drug delivery systems, including oral, injectable, topical, and ocular approaches, highlighting their significance in enhancing therapeutic outcomes. Additionally, we address the challenges faced in the clinical translation of hydrogels and propose future directions for leveraging their potential in personalized medicine and regenerative healthcare solutions.

Formulating biopharmaceuticals using three-dimensional printing

Additive manufacturing, commonly referred to as three-dimensional (3D) printing, has the potential to initiate a paradigm shift in the field of medicine and drug delivery. Ever since the advent of the first-ever United States Food and Drug Administration (US FDA)-approved 3D printed tablet, there has been an increased interest in the application of this technology in drug delivery and biomedical applications. 3D printing brings us one step closer to personalized medicine, hence rendering the "one size fits all" concept in drug dosing obsolete. In this review article, we focus on the recent developments in the field of modified drug delivery systems in which various types of additive manufacturing technologies are applied.

Novel Therapeutic Hybrid Systems Using Hydrogels and Nanotechnology: A Focus on Nanoemulgels for the Treatment of Skin Diseases

Topical and transdermal drug delivery are advantageous administration routes, especially when treating diseases and conditions with a skin etiology. Nevertheless, conventional dosage forms often lead to low therapeutic efficacy, safety issues, and patient noncompliance. To tackle these issues, novel topical and transdermal platforms involving nanotechnology have been developed. This review focuses on the latest advances regarding the development of nanoemulgels for skin application, encapsulating a wide variety of molecules, including already marketed drugs (miconazole, ketoconazole, fusidic acid, imiquimod, meloxicam), repurposed marketed drugs (atorvastatin, omeprazole, leflunomide), natural-derived compounds (eucalyptol, naringenin, thymoquinone, curcumin, chrysin, brucine, capsaicin), and other synthetic molecules (ebselen, tocotrienols, retinyl palmitate), for wound healing, skin and skin appendage infections, skin inflammatory diseases, skin cancer, neuropathy, or anti-aging purposes. Developed formulations revealed adequate droplet size, PDI, viscosity, spreadability, pH, stability, drug release, and drug permeation and/or retention capacity, having more advantageous characteristics than current marketed formulations. In vitro and/or in vivo studies established the safety and efficacy of the developed formulations, confirming their therapeutic potential, and making them promising platforms for the replacement of current therapies, or as possible adjuvant treatments, which might someday effectively reach the market to help fight highly incident skin or systemic diseases and conditions.

Nanocomposite of starch, gelatin and itaconic acid-based biodegradable hydrogel and ZnO/cellulose nanofiber: A pH-sensitive sustained drug delivery vehicle

In recent years, hydrogels as drug carriers have been receiving great interest due to their ability to change their behavior in response to one or more external stimuli. However, their initial burst release profile limits their practical applications. Therefore, we prepared a bio-based hydrogel nanocomposite (HNC) using starch, itaconic acid, acrylic acid and gelatin in the presence of CNF/ZnO-based nanohybrid (ZONH) and used it to evaluate the pH-sensitive drug release properties in different pH solutions. The prepared HNCs were analyzed using various spectroscopic and microscopic techniques. The BET analysis and swelling test of the HNC indicated improved porosity and swelling capacity due to the addition of ZONH. From the drug release study, sustained drug release rate was observed at pH 4 than those at pH 7.4 and 9, indicating controlled release as well as pH responsive behavior of the HNC. Moreover, the drug released HNC was reused as a photocatalyst for dye degradation and achieved good degradation (%). The antibacterial activity of ZONH and HNC was observed against EC and SA bacterial strains from the antibacterial test. In summary, the prepared HNC can be considered as a potential sustainable DDS for biomedical applications as well as a photocatalyst for dye contaminated water treatment.

Topical delivery of seriniquinone for treatment of skin cancer and fungal infections is enabled by a liquid crystalline lamellar phase

Seriniquinone (SQ) was initially described by our group as an antimelanoma drug candidate and now also as an antifungal drug candidate. Despite its promising in vitro effects, SQ translation has been hindered by poor water-solubility. In this paper, we described the challenging nanoformulation process of SQ, which culminated in the selection of a phosphatidylcholine-based lamellar phase (PLP1). Liposomes and nanostructured lipid carriers were also evaluated but failed to encapsulate the compound. SQ-loaded PLP1 (PLP1-SQ) was characterized for the presence of sedimented or non-dissolved SQ, rheological and thermal behavior, and irritation potential with hen's egg test on the chorioallantoic membrane (HET-CAM). PLP1 influence on transepidermal water loss (TEWL) and skin penetration of SQ was assessed in a porcine ear skin model, while biological activity was evaluated against melanoma cell lines (SK-MEL-28 and SK-MEL-147) and C. albicans SC5314. Despite the presence of few particles of non-dissolved SQ (observed under the microscope 2 days after formulation obtainment), PLP1 tripled SQ retention in viable skin layers compared to SQ solution at 12 h. This effect did not seem to relate to formulation-induced changes on the barrier function, as no increases in TEWL were observed. No sign of vascular toxicity in the HET-CAM model was observed after cutaneous treatment with PLP1. SQ activity was maintained on melanoma cells after 48 h-treatment (IC50 values of 0.59-0.98 µM) whereas the minimum inhibitory concentration (MIC) against C. albicans after 24 h-treatment was 32-fold higher. These results suggest that a safe formulation for SQ topical administration was developed, enabling further in vivo studies.

Implantable magnetically-actuated capsule for on-demand delivery

Many implantable drug delivery systems (IDDS) have been developed for long-term, pulsatile drug release. However, they are often limited by bulky size, complex electronic components, unpredictable drug delivery, as well as the need for battery replacement and consequent replacement surgery. Here, we develop an implantable magnetically-actuated capsule (IMAC) and its portable magnetic actuator (MA) for on-demand and robust drug delivery in a tether-free and battery-free manner. IMAC utilizes the bistable mechanism of two magnetic balls inside IMAC to trigger drug delivery under a strong magnetic field (|Ba| > 90 mT), ensuring precise and reproducible drug delivery (9.9 ± 0.17 μg per actuation, maximum actuation number: 180) and excellent anti-magnetic capability (critical trigger field intensity: ∼90 mT). IMAC as a tetherless robot can navigate to and anchor at the lesion sites driven by a gradient magnetic field (∇ Bg = 3 T/m, |Bg| < 60 mT), and on-demand release drug actuated by a uniform magnetic field (|Ba| = ∼100 mT) within the gastrointestinal tract. During a 15-day insulin administration in vivo, the diabetic rats treated with IMAC exhibited highly similar pharmacokinetic and pharmacodynamic profiles to those administrated via subcutaneous injection, demonstrating its robust and on-demand drug release performance. Moreover, IMAC is biocompatible, batter-free, refillable, miniature (only Φ 6.3 × 12.3 mm3), and lightweight (just 0.8 g), making it an ideal alternative for precise implantable drug delivery and friendly patient-centered drug administration.

Nano-composite system of traditional Chinese medicine for ocular applications: molecular docking and three-dimensional modeling insight for intelligent drug evaluation

The absorption of drugs was impeded in the posterior part of the eye due to the special structure. In addition, it was crucial to comprehend transport laws of molecules in ocular drug delivery for designing effective strategies. However, the current quality evaluation methods of the eye were backward and lack of dynamic monitoring of drug processes in vivo. Herein, nano-drug delivery system and three-dimensional (3D) model were combined to overcome the problems of low bioavailability and diffusion law. The model drugs were screened by molecular docking. The flexible nano-liposome (FNL) and temperature-sensitive gel (TSG) composite formulation was characterized through comprehensive evaluation. COMSOL software was utilized to build 3D eyeball to predict the bioavailability of drugs. The size of the preparation was about 98.34 nm which is relatively optimal for the enhanced permeability of the eyes. The formulation showed a stronger safety and non-irritant. The pharmacokinetics results of aqueous humor showed that the AUC of two drugs in this system increased by 3.79 and 3.94 times, respectively. The results of 3D calculation model proved that the concentrations of drugs reaching the retina were 1.90×10-5 mol/m3 and 6.37×10-6 mol/m3. In conclusion, the FNL-TSG markedly improved the bioavailability of multiple components in the eye. More importantly, a simplified 3D model was developed to preliminarily forecast the bioavailability of the retina after drug infusion, providing technical support for the accurate evaluation of ocular drug delivery. It provided new pattern for the development of intelligent versatile ophthalmic preparations.

Transdermal Delivery of Photosensitizer-Catalase Conjugate by Fluorinated Polyethylenimine for Enhanced Topical Photodynamic Therapy of Bacterial Infections

Pathogenic bacteria induce subcutaneous infections pose serious threats to global public health. Recently, photodynamic therapy (PDT) has been proposed as a non-invasive approach for anti-microbial treatment without the risk to induce drug resistance. However, due to the hypoxic environment of most anaerobiont-infected sites, the therapeutic efficacy of oxygen consuming PDT has been limited. Herein, a transdermal delivery system is reported to allow effective delivery of photosensitizers into infected skin for PDT treatment of skin infections by bacteria. Considering the overproduction of hydrogen peroxide (H2 O2 ) in the abscess area, catalase (CAT), an enzyme that triggers H2 O2 decomposition to generate O2 , is conjugated with chlorine e6 (Ce6) to form a photosensitizer conjugate (Ce6-CAT) as an enhanced PDT agent against Staphylococcus Aureus. After screening a series of fluorinated low molecular weight polyethylenimine (F-PEI) with different fluorination degrees, the optimized F-PEI formulation is identified with the best transdermal delivery ability system. Upon mixing, the formed Ce6-CAT@F-PEI nanocomplex shows effective transdermal penetration after being applied to the skin surface. With light exposure of the infected skin, highly effective in vivo anti-bacterial PDT therapeutic effect with Ce6-CAT@F-PEI is observed. This work proposes a transdermal PDT therapeutic nanomedicine particularly promising for the anti-bacterial treatment of skin infections.

Advance and Challenges in the Treatment of Skin Diseases with the Transdermal Drug Delivery System

Skin diseases are among the most prevalent non-fatal conditions worldwide. The transdermal drug delivery system (TDDS) has emerged as a promising approach for treating skin diseases, owing to its numerous advantages such as high bioavailability, low systemic toxicity, and improved patient compliance. However, the effectiveness of the TDDS is hindered by several factors, including the barrier properties of the stratum corneum, the nature of the drug and carrier, and delivery conditions. In this paper, we provide an overview of the development of the TDDS from first-generation to fourth-generation systems, highlighting the characteristics of each carrier in terms of mechanism composition, penetration method, mechanism of action, and recent preclinical studies. We further investigated the significant challenges encountered in the development of the TDDS and the crucial significance of clinical trials.

Drug Delivery through Epidermal Tissue Cells by Functionalized Biosilica from Diatom Microalgae

Diatom microalgae are a natural source of fossil biosilica shells, namely the diatomaceous earth (DE), abundantly available at low cost. High surface area, mesoporosity and biocompatibility, as well as the availability of a variety of approaches for surface chemical modification, make DE highly profitable as a nanostructured material for drug delivery applications. Despite this, the studies reported so far in the literature are generally limited to the development of biohybrid systems for drug delivery by oral or parenteral administration. Here we demonstrate the suitability of diatomaceous earth properly functionalized on the surface with n-octyl chains as an efficient system for local drug delivery to skin tissues. Naproxen was selected as a non-steroidal anti-inflammatory model drug for experiments performed both in vitro by immersion of the drug-loaded DE in an artificial sweat solution and, for the first time, by trans-epidermal drug permeation through a 3D-organotypic tissue that better mimics the in vivo permeation mechanism of drugs in human skin tissues. Octyl chains were demonstrated to both favour the DE adhesion onto porcine skin tissues and to control the gradual release and the trans-epidermal permeation of Naproxen within 24 h of the beginning of experiments. The evidence of the viability of human epithelial cells after permeation of the drug released from diatomaceous earth, also confirmed the biocompatibility with human skin of both Naproxen and mesoporous biosilica from diatom microalgae, disclosing promising applications of these drug-delivery systems for therapies of skin diseases.

New Insights in Topical Drug Delivery for Skin Disorders: From a Nanotechnological Perspective

Skin, the largest organ in humans, is an efficient route for the delivery of drugs as it circumvents several disadvantages of the oral and parenteral routes. These advantages of skin have fascinated researchers in recent decades. Drug delivery via a topical route includes moving the drug from a topical product to a locally targeted region with dermal circulation throughout the body and deeper tissues. Still, due to the skin's barrier function, delivery through the skin can be difficult. Drug delivery to the skin using conventional formulations with micronized active components, for instance, lotions, gels, ointments, and creams, results in poor penetration. The use of nanoparticulate carriers is one of the promising strategies, as it provides efficient delivery of drugs through the skin and overcomes the disadvantage of traditional formulations. Nanoformulations with smaller particle sizes contribute to improved permeability of therapeutic agents, targeting, stability, and retention, making nanoformulations ideal for drug delivery through a topical route. Achieving sustained release and preserving a localized effect utilizing nanocarriers can result in the effective treatment of numerous infections or skin disorders. This article aims to evaluate and discuss the most recent developments of nanocarriers as therapeutic agent vehicles for skin conditions with patent technology and a market overview that will give future directions for research. As topical drug delivery systems have shown great preclinical results for skin problems, for future research directions, we anticipate including in-depth studies of nanocarrier behavior in various customized treatments to take into account the phenotypic variability of the disease.

Local Delivery and Controlled Release Drugs Systems: A New Approach for the Clinical Treatment of Periodontitis Therapy

Periodontitis is an inflammatory disease of the gums characterized by the degeneration of periodontal ligaments, the formation of periodontal pockets, and the resorption of the alveolar bone, which results in the destruction of the teeth's supporting structure. Periodontitis is caused by the growth of diverse microflora (particularly anaerobes) in the pockets, releasing toxins and enzymes and stimulating the immune system. Various approaches, both local and systemic, have been used to treat periodontitis effectively. Successful treatment depends on reducing bacterial biofilm, bleeding on probing (BOP), and reducing or eliminating pockets. Currently, the use of local drug delivery systems (LDDSs) as an adjunctive therapy to scaling and root planing (SRP) in periodontitis is a promising strategy, resulting in greater efficacy and fewer adverse effects by controlling drug release. Selecting an appropriate bioactive agent and route of administration is the cornerstone of a successful periodontitis treatment plan. In this context, this review focuses on applications of LDDSs with varying properties in treating periodontitis with or without systemic diseases to identify current challenges and future research directions.

Plaster Gel Loaded with Silver Nanoparticle-Mediated Ganoderma applanatum: from Fabrication to Evaluation

Traditional Asian remedies have mainly employed the macrofungus Ganoderma applanatum, which belongs to the family Ganodermataceae, as a medicinal mushroom due to its high antibacterial and antioxidant activity. Extracts of the fungus can be synthesized into nanoparticles, which are subsequently produced as plaster gels. Synthesized silver nanoparticle-mediated G. applanatum was discovered to have the greatest ability to inhibit bacterial growth in S. epidermidis. When applied to the skin, the prepared plaster gel converted from a gel to a film; thus, both gel and film generation are characteristic of its formulation. The plaster gel that was made was found to be consistent and attractive, and the yellow color had darkened. Its viscosity and pH were appropriate for the application and allowed it to remain on the skin without dripping or reacting with the skin until it dried. A shorter duration for film formation is possible. The film's tensile was slightly reduced, and it exhibited excellent thermal stability. Decomposition of the generated film occurred at a slower rate, which constrained the polymer chain's ability to move. The semi-crystalline structure was characteristic of the film. It was found that particles were distributed in the film. Rapid release from plaster gel within 4 h was seen, and this was followed by a period of a slowly declining release rate over 12 h. The accurate first-order kinetic used to estimate the release rate of the formulation. The plaster gel demonstrated greater antibacterial activity than the MIC value indicated. The in vivo evaluation was positive and showed no skin irritation. The formulation showed good stability. Therefore, this indicated that the prepared plaster gel is appropriate for topical pharmaceutical delivery and safe for skin application.

Overcoming Treatment Challenges in Posterior Segment Diseases with Biodegradable Nano-Based Drug Delivery Systems

Posterior segment eye diseases present a challenge in treatment due to the complex structures in the eye that serve as robust static and dynamic barriers, limiting the penetration, residence time, and bioavailability of topical and intraocular medications. This hinders effective treatment and requires frequent dosing, such as the regular use of eye drops or visits to the ophthalmologist for intravitreal injections, to manage the disease. Moreover, the drugs must be biodegradable to minimize toxicity and adverse reactions, as well as small enough to not affect the visual axis. The development of biodegradable nano-based drug delivery systems (DDSs) can be the solution to these challenges. First, they can stay in ocular tissues for longer periods of time, reducing the frequency of drug administration. Second, they can pass through ocular barriers, offering higher bioavailability to targeted tissues that are otherwise inaccessible. Third, they can be made up of polymers that are biodegradable and nanosized. Hence, therapeutic innovations in biodegradable nanosized DDS have been widely explored for ophthalmic drug delivery applications. In this review, we will present a concise overview of DDSs utilized in the treatment of ocular diseases. We will then examine the current therapeutic challenges faced in the management of posterior segment diseases and explore how various types of biodegradable nanocarriers can enhance our therapeutic arsenal. A literature review of the pre-clinical and clinical studies published between 2017 and 2023 was conducted. Through the advances in biodegradable materials, combined with a better understanding of ocular pharmacology, the nano-based DDSs have rapidly evolved, showing great promise to overcome challenges currently encountered by clinicians.

Topical Drug Delivery in the Treatment of Skin Wounds and Ocular Trauma Using the Platform Wound Device

Topical treatment of injuries such as skin wounds and ocular trauma is the favored route of administration. Local drug delivery systems can be applied directly to the injured area, and their properties for releasing therapeutics can be tailored. Topical treatment also reduces the risk of adverse systemic effects while providing very high therapeutic concentrations at the target site. This review article highlights the Platform Wound Device (PWD) (Applied Tissue Technologies LLC, Hingham, MA, USA) for topical drug delivery in the treatment of skin wounds and eye injuries. The PWD is a unique, single-component, impermeable, polyurethane dressing that can be applied immediately after injury to provide a protective dressing and a tool for precise topical delivery of drugs such as analgesics and antibiotics. The use of the PWD as a topical drug delivery platform has been extensively validated in the treatment of skin and eye injuries. The purpose of this article is to summarize the findings from these preclinical and clinical studies.

Lipid-core nanoparticles: Classification, preparation methods, routes of administration and recent advances in cancer treatment

Nanotechnological drug delivery platforms represent a new paradigm for cancer therapeutics as they improve the pharmacokinetic profile and distribution of chemotherapeutic agents over conventional formulations. Among nanoparticles, lipid-based nanoplatforms possessing a lipid core, that is, lipid-core nanoparticles (LCNPs), have gained increasing interest due to lipid properties such as high solubilizing potential, versatility, biocompatibility, and biodegradability. However, due to the wide spectrum of morphologies and types of LCNPs, there is a lack of consensus regarding their terminology and classification. According to the current state-of-the-art in this critical review, LCNPs are defined and classified based on the state of their lipidic components in liquid lipid nanoparticles (LLNs). These include lipid nanoemulsions (LNEs) and lipid nanocapsules (LNCs), solid lipid nanoparticles (SLNs) and nanostructured lipid nanocarriers (NLCs). In addition, we present a comprehensive and comparative description of the methods employed for their preparation, routes of administration and the fundamental role of physicochemical properties of LCNPs for efficient antitumoral drug-delivery application. Market available LCNPs, clinical trials and preclinical in vivo studies of promising LCNPs as potential treatments for different cancer pathologies are summarized.

Synthesis of Bio-Based Polyester from Microbial Lipidic Residue Intended for Biomedical Application

In the last decade, selectively tuned bio-based polyesters have been increasingly used for their clinical potential in several biomedical applications, such as tissue engineering, wound healing, and drug delivery. With a biomedical application in mind, a flexible polyester was produced by melt polycondensation using the microbial oil residue collected after the distillation of β-farnesene (FDR) produced industrially by genetically modified yeast, Saccharomyces cerevisiae. After characterization, the polyester exhibited elongation up to 150% and presented T_g of -51.2 °C and T_m of 169.8 °C. In vitro degradation revealed a mass loss of about 87% after storage in PBS solution for 11 weeks under accelerated conditions (40 °C, RH = 75%). The water contact angle revealed a hydrophilic character, and biocompatibility with skin cells was demonstrated. 3D and 2D scaffolds were produced by salt-leaching, and a controlled release study at 30 °C was performed with Rhodamine B base (RBB, 3D) and curcumin (CRC, 2D), showing a diffusion-controlled mechanism with about 29.3% of RBB released after 48 h and 50.4% of CRC after 7 h. This polymer offers a sustainable and eco-friendly alternative for the potential use of the controlled release of active principles for wound dressing applications.

Biocompatible phospholipid-based nanovesicular drug delivery system of ketoprofen: Systematic development, optimization, and preclinical evaluation

The present work involved development of phospholipid-based permeation enhancing nanovesicles (PENVs) for topical delivery of ketoprofen. Screening of phospholipids and process parameters was performed. Central composite design was used for optimization of factors, that is, amount (%, w/w) of phospholipid and ethanol at three levels. The optimized nanovesicles (NVs) were loaded with different terpenes and then incorporated into a gel base. Optimized NVs exhibited 69% entrapment efficiency, 51% transmittance, 328 nm mean vesicle size, and polydispersity index of 0.25. In vitro release kinetics evaluation indicated best fitting as per Korsemeyer-Peppa's model and drug release via Fickian-diffusion mechanism. The optimized NVs loaded with mint terpene showed minimal degree of deformability and maximal elasticity as compared with the conventional NVs and liposomes. Rheology and texture analysis indicated pseudoplastic flow and smooth texture of the vesicle gel formulation. Ex vivo permeation studies across Wistar rat skin indicated low penetration (0.43-fold decrease) and high skin retention (4.26-fold increase) of ketoprofen from the optimized PENVs gel vis-à-vis the conventional gel. Skin irritancy study indicated lower scores for PENVs gel construing its biocompatible nature. Stability studies confirmed cold storage is best suitable for vesicle gel, and optimized PENVs were found to be suitable for topical delivery of ketoprofen.

The Assessment of Skin Homeostasis Changes after Using Different Types of Excipients in Healthy Individuals

Excipients are used as vehicles for topical treatments; however, there are not many studies that evaluate the impact of different excipients themselves. The aim of this research is to assess skin homeostasis changes in healthy individuals after using water/oil (W/O), oil/water (O/W), Beeler base, foam and Vaseline excipients. A within-person randomized trial was conducted that included healthy individuals without previous skin diseases. Skin barrier function parameters, including stratum corneum hydration (SCH), transepidermal water loss (TEWL), pH, temperature, erythema, melanin and elasticity (R0, R2, R5 and R7), were measured on the volar forearm before and after using each excipient. Sixty participants were included in the study, with a mean age of 32 years. After applying w/o excipient erythema decreased by 25 AU, (p < 0.001) and elasticity increased by 6%. After using the o/w excipient, erythema decreased by 39.36 AU (p < 0.001) and SCH increased by 6.85 AU (p = 0.009). When applying the Beeler excipient, erythema decreased by 41.23 AU (p < 0.001) and SCH increased by 15.92 AU (p < 0.001). Foam and Vaseline decreased TEWL and erythema. Excipients have a different impact on skin barrier function. Knowing the effect of excipients on the skin could help to develop new topical treatments and help specialists to choose the best excipient according to the pathology.

A Biocompatible Liquid Pillar[n]arene-Based Drug Reservoir for Topical Drug Delivery

Advanced external preparations that possess a sustained-release effect and integrate few irritant elements are urgently needed to satisfy the special requirements of topical administration in the clinic. Here, a series of liquid pillar[n]arene-bearing varying-length oligoethylene oxide chains (OEPns) were designed and synthesized. Following rheological property and biocompatibility investigations, pillar[6]arene with triethylene oxide substituents (TEP6) with satisfactory cavity size were screened as optimal candidate compounds. Then, a supramolecular liquid reservoir was constructed from host-guest complexes between TEP6 and econazole nitrate (ECN), an external antimicrobial agent without additional solvents. In vitro drug-release studies revealed that complexation by TEP6 could regulate the release rate of ECN and afford effective cumulative amounts. In vivo pharmacodynamic studies confirmed the formation of a supramolecular liquid reservoir contributed to the accelerated healing rate of a S. aureus-infected mouse wound model. Overall, these findings have provided the first insights into the construction of a supramolecular liquid reservoir for topical administration.

Microneedles-based drug delivery strategies: A breakthrough approach for the management of pain

Pain is a personalized event or body alarm system that can limit a patient's activities and lead to negative repercussions. The commercially available conventional treatment strategies like oral, parenteral, and topical drug delivery systems for pain management are associated with side effects and poor patient compliance. The transdermal route is eminent for its painless distribution. Among transdermal drug delivery system, microneedles (MNs) are gaining attention for their application with delivery at the deeper dermal layer because it bypasses the major barrier of the skin, easily accesses the skin dermal microcirculation, prevents damage to dermal blood vessels, and can be simply inserted into the skin without utilizing any additional applicator devices. Hence, considered a promising drug delivery strategy with high patient compliance. This review highlights the recent advancements of MNs in pain management. The present work mainly emphasizes all the case studies reported from the past 10 years that utilize MNs containing therapeutics in the treatment of chronic pain-associated diseases like rheumatoid arthritis, neuropathic pain, osteoarthritis, psoriatic arthritis, and atopic dermatitis. These studies have proven the efficacious application of MNs in the management of chronic pain and inflammation. The review also covered the clinical trials, patents, and future goals of pain management by using MNs.

Adapting Clofazimine for Treatment of Cutaneous Tuberculosis by Using Self-Double-Emulsifying Drug Delivery Systems

Although chemotherapeutic treatment regimens are currently available, and considerable effort has been lavished on the development of new drugs for the treatment of tuberculosis (TB), the disease remains deeply intractable and widespread. This is due not only to the nature of the life cycle and extraordinarily disseminated habitat of the causative pathogen, principally Mycobacterium tuberculosis (Mtb), in humans and the multi-drug resistance of Mtb to current drugs, but especially also to the difficulty of enabling universal treatment of individuals, immunocompromised or otherwise, in widely differing socio-economic environments. For the purpose of globally eliminating TB by 2035, the World Health Organization (WHO) introduced the "End-TB" initiative by employing interventions focusing on high impact, integrated and patient-centered approaches, such as individualized therapy. However, the extraordinary shortfall in stipulated aims, for example in actual treatment and in TB preventative treatments during the period 2018-2022, latterly and greatly exacerbated by the COVID-19 pandemic, means that even greater pressure is now placed on enhancing our scientific understanding of the disease, repurposing or repositioning old drugs and developing new drugs as well as evolving innovative treatment methods. In the specific context of multidrug resistant Mtb, it is furthermore noted that the incidence of extra-pulmonary TB (EPTB) has significantly increased. This review focusses on the potential of utilizing self-double-emulsifying drug delivery systems (SDEDDSs) as topical drug delivery systems for the dermal route of administration to aid in treatment of cutaneous TB (CTB) and other mycobacterial infections as a prelude to evaluating related systems for more effective treatment of CTB and other mycobacterial infections at large. As a starting point, we consider here the possibility of adapting the highly lipophilic riminophenazine clofazimine, with its potential for treatment of multi-drug resistant TB, for this purpose. Additionally, recently reported synergism achieved by adding clofazimine to first-line TB regimens signifies the need to consider clofazimine. Thus, the biological effects and pharmacology of clofazimine are reviewed. The potential of plant-based oils acting as emulsifiers, skin penetration enhancers as well as these materials behaving as anti-microbial components for transporting the incorporated drug are also discussed.

Iontophoretic ocular delivery of latanoprost-loaded nanoparticles via skin-attached electrodes

Prolonged drug efficacy to reduce the number of administrations is a key factor in the successful treatment of glaucoma through topical drug delivery to the eye. Therefore, we propose a new strategy for iontophoretic ocular delivery of drug-loaded nanoparticles. Considering safety and convenience, our strategy is involved with topical administration of the drug-loaded nanoparticles followed by their permeation into the eye tissues via noninvasive iontophoresis, using the skin-attached electrodes. Thus, those nanoparticles stayed longer in the eye, and during this period, the drug was released in a sustained manner, thereby prolonging drug exposure even with one-time treatment. The nanoparticles were made of poly(lactic-co-glycolic acid) (PLGA), which were loaded with a glaucoma drug, latanoprost. We varied the size of the nanoparticles at 100, 200, 300, and 500 nm and sought to find the optimum size under the fixed conditions for iontophoresis proposed in this work (4 mA; 30 min). Even with iontophoresis through the skin-attached electrodes, the nanoparticles were indeed deposited in the eye tissues, where with an increase in particle size, drug release was more sustained, but fewer particles could permeate into the eye tissues. Because of these two competing factors, iontophoretic delivery of the 300-nm particles exhibited the most prolonged drug efficacy in vivo for more than 7 days, and showed an approximately 23-fold increase in drug efficacy compared with that of Xalatan®, a commercially available eye drop of latanoprost developed for once-a-day administration every day. STATEMENT OF SIGNIFICANCE: To treat glaucoma, conventional eye drops are often prescribed; however, they often require multiple daily administrations due to rapid preocular clearance. To resolve this, we suggest a noninvasive iontophoretic ocular delivery of latanoprost-loaded PLGA nanoparticles using the skin-attached electrodes. Even with iontophoresis via the skin-attached electrodes, the nanoparticles can indeed be deposited into the eye tissues. However, with an increase in particle size, fewer particles can permeate into the eye tissues, although drug release is more sustained. Therefore, the particles with a size of 300 nm show the optimal in vivo delivery profile in this work, where the drug efficacy can be extended for more than 7 days with a single administration.

Mechanism and Application of Chitosan and Its Derivatives in Promoting Permeation in Transdermal Drug Delivery Systems: A Review

The mechanisms and applications of chitosan and its derivatives in transdermal drug delivery to promote drug permeation were reviewed in this paper. Specifically, we summarized the permeation-promoting mechanisms of chitosan and several of its derivatives, including changing the structure of stratum corneum proteins, acting on the tight junction of granular layers, affecting intercellular lipids, and increasing the water content of stratum corneum. These mechanisms are the reason why chitosan and its derivatives can increase the transdermal permeation of drugs. In addition, various transdermal preparations containing chitosan and its derivatives were summarized, and their respective advantages were expounded, including nanoparticles, emulsions, transdermal microneedles, nanocapsules, transdermal patches, transdermal membranes, hydrogels, liposomes, and nano-stents. The purpose of this review is to provide a theoretical basis for the further and wider application of chitosan in transdermal drug delivery systems. In the future, research results of chitosan and its derivatives in transdermal drug delivery need more support from in vivo experiments, as well as good correlation between in vitro and in vivo experiments. In conclusion, the excellent permeability-promoting property, good biocompatibility, and biodegradability of chitosan and its derivatives make them ideal materials for local transdermal drug delivery.

Development of rapamycin-encapsulated exosome-mimetic nanoparticles-in-PLGA microspheres for treatment of hemangiomas

We have previously developed several kinds of rapamycin-encapsulated nanoparticles to achieve sustained release of rapamycin to treat hemangioma. However, lack of intrinsic targeting and easy clearance by the immune system are major hurdles that artificial fabricated nanoparticles must overcome. We constructed rapamycin-encapsulated macrophage-derived exosomes mimic nanoparticles-in-microspheres (RNM), to achieve the goal of continuous targeted therapy of hemangiomas. The rapamycin-encapsulated exosome mimic nanoparticles (RN) were firstly prepared by the extrusion-based method from the U937 cells (the human macrophage cell line). After then, RN was encapsulated with PLGA (poly(lactic-co-glycolic acid)) microspheres to obtain RNM. The release profile, targeting activity, and biological activity of RN and RNM were investigated on hemangioma stem cells (HemSCs). RN has a size of 100 nm in diameter, with a rapamycin encapsulation efficacy (EE) of 83%. The prepared microspheres RNM have a particle size of ~30 µm), and the drug EE of RNM is 34%. The sustained release of RNM can remarkably be achieved for 40 days. As expected, RN and RNM showed effective inhibition of cellular proliferation, significant cellular apoptosis, and remarkable repressed expression of angiogenesis factors in HemSCs. Our results showed that RNM is an effective approach for prolonged and effective delivery of rapamycin to hemangiomas.

Novel Hydrogels for Topical Applications: An Updated Comprehensive Review Based on Source

Active pharmaceutical ingredients (API) or drugs are normally not delivered as pure chemical substances (for the prevention or the treatment of any diseases). APIs are still generally administered in prepared formulations, also known as dosage forms. Topical administration is widely used to deliver therapeutic agents locally because it is convenient and cost-effective. Since earlier civilizations, several types of topical semi-solid dosage forms have been commonly used in healthcare society to treat various skin diseases. A topical drug delivery system is designed primarily to treat local diseases by applying therapeutic agents to surface level parts of the body such as the skin, eyes, nose, and vaginal cavity. Nowadays, novel semi-solids can be used safely in pediatrics, geriatrics, and pregnant women without the possibility of causing any allergy reactions. The novel hydrogels are being used in a wide range of applications. At first, numerous hydrogel research studies were carried out by simply adding various APIs in pure form or dissolved in various solvents to the prepared hydrogel base. However, numerous research articles on novel hydrogels have been published in the last five to ten years. It is expected that novel hydrogels will be capable of controlling the APIs release pattern. Novel hydrogels are made up of novel formulations such as nanoparticles, nanoemulsions, microemulsions, liposomes, self-nano emulsifying drug delivery systems, cubosomes, and so on. This review focus on some novel formulations incorporated in the hydrogel prepared with natural and synthetic polymers.

Polymeric Nanoparticles-Loaded Hydrogels for Biomedical Applications: A Systematic Review on In Vivo Findings

Clinically available medications face several hurdles that limit their therapeutic activity, including restricted access to the target tissues due to biological barriers, low bioavailability, and poor pharmacokinetic properties. Drug delivery systems (DDS), such as nanoparticles (NPs) and hydrogels, have been widely employed to address these issues. Furthermore, the DDS improves drugs’ therapeutic efficacy while reducing undesired side effects caused by the unspecific distribution over the different tissues. The integration of NPs into hydrogels has emerged to improve their performance when compared with each DDS individually. The combination of both DDS enhances the ability to deliver drugs in a localized and targeted manner, paired with a controlled and sustained drug release, resulting in increased drug therapeutic effectiveness. With the incorporation of the NPs into hydrogels, it is possible to apply the DDS locally and then provide a sustained release of the NPs in the site of action, allowing the drug uptake in the required location. Additionally, most of the materials used to produce the hydrogels and NPs present low toxicity. This article provides a systematic review of the polymeric NPs-loaded hydrogels developed for various biomedical applications, focusing on studies that present in vivo data.

Design of Novel Nanoemulsion Formulations for Topical Ocular Delivery of Itraconazole: Development, Characterization and In Vitro Bioassay

Purpose: The objective of this study was to design and develop nanoemulsion formulations of Itraconazole (ITZ), a water-insoluble, potent antifungal drug using the spontaneous emulsification method, to improve the ocular delivery and achieve a sustained release of the drug. Methods: The oil was selected on the basis of the ITZ solubility while the surfactant and co-surfactant were selected based on the thermodynamic stability and globule size. Following the selection of components, a pseudo-ternary phase diagram was constructed for the most promising formulation (F11) using benzyl benzoate (BB) as the oil, Eumulgin CO40 as the surfactant, and propylene glycol as the co-surfactant, by the design of experiments (DoE). Results: F7 and F11 formulations were found to have an average globule size of 223.5 ± 10.7 nm and 157.5 ± 14.2 nm, besides thermodynamic stability and suitable physicochemical properties. F11 possessed an almost seven-fold higher cumulative percentage of in vitro released ITZ, in comparison to ITZ aqueous suspension after 24 hours. The release data suggested that the best fitted kinetical model for F11 and F7 was the Higuchi and Korsmeyer-Peppas model. Conclusion: The extended-release of the drug beside an acceptable amount of loaded ITZ suggested that nanoemulsion is suitable for the delivery of the ITZ.

Microemulsified Gel Formulations for Topical Delivery of Clotrimazole: Structural and In Vitro Evaluation

Microemulsified gels (μEGs) with fascinating functions have become indispensable as topical drug delivery systems due to their structural flexibility, high stability, and facile manufacturing process. Topical administration is an attractive alternative to traditional methods because of advantages such as noninvasive administration, bypassing first-pass metabolism, and improving patient compliance. In this article, we report on the new formulations of microemulsion-based gels suitable for topical pharmaceutical applications using biocompatible and ecological ingredients. For this, two biocompatible μE formulations comprising clove oil/Brij-35/water/ethanol (formulation A) and clove oil/Brij-35/water/1-propanol (formulation B) were developed to encapsulate and improve the load of an antimycotic drug, Clotrimazole (CTZ), and further gelatinized to control the release of CTZ through skin barriers. By delimiting the pseudo-ternary phase diagram, optimum μE formulations with clove oil (∼15%) and Brij-35 (∼30%) were developed, keeping constant surfactant/co-surfactant ratio (1:1), to upheld 2.0 wt % CTZ. The as-developed formulations were further converted into smart gels by adding 2.0 wt % carboxymethyl cellulose (CMC) as a cross-linker to adhere to the controlled release of CTZ through complex skin barriers. Electron micrographs show a fine, monodispersed collection of CTZ-μE nanodroplets (∼60 nm), which did not coalesce even after gelation, forming spherical CTZ-μEG (∼90 nm). However, the maturity of CTZ nanodroplets observed by dynamic light scattering suggests the affinity of CTZ for the nonpolar microenvironment, which was further supported by the peak-to-peak correlation of Fourier transform infrared (FTIR) analysis and fluorescence measurement. In addition, HPLC analysis showed that the in vitro permeation release of CTZ-μEG from rabbit skin in the ethanolic phosphate buffer (pH = 7.4) was significantly increased by >98% within 6.0 h. This indicates the sustained release of CTZ in μEBG and the improvement in transdermal therapeutic efficacy of CTZ over its traditional topical formulations.

3D-Printed Products for Topical Skin Applications: From Personalized Dressings to Drug Delivery

3D printing has been widely used for the personalization of therapies and on-demand production of complex pharmaceutical forms. Recently, 3D printing has been explored as a tool for the development of topical dosage forms and wound dressings. Thus, this review aims to present advances related to the use of 3D printing for the development of pharmaceutical and biomedical products for topical skin applications, covering plain dressing and products for the delivery of active ingredients to the skin. Based on the data acquired, the important growth in the number of publications over the last years confirms its interest. The semisolid extrusion technique has been the most reported one, probably because it allows the use of a broad range of polymers, creating the most diverse therapeutic approaches. 3D printing has been an excellent field for customizing dressings, according to individual needs. Studies discussed here imply the use of metals, nanoparticles, drugs, natural compounds and proteins and peptides for the treatment of wound healing, acne, pain relief, and anti-wrinkle, among others. The confluence of 3D printing and topical applications has undeniable advantages, and we would like to encourage the research groups to explore this field to improve the patient's life quality, adherence and treatment efficacy.

Transfersomes as alternative topical nanodosage forms for the treatment of skin disorders

Topical drug delivery is a promising approach to treat different skin disorders. However, it remains a challenge mainly due to the nature and rigidity of the nanosystems, which limit deep skin penetration, and the unsuccessful demonstration of clinical benefits; greater penetration by itself, does not ensure pharmacological success. In this context, transfersomes have appeared as promising nanosystems; deformability, their unique characteristic, allows them to pass through the epidermal microenvironment, improving the skin drug delivery. This review focuses on the comparison of transfersomes with other nanosystems (e.g., liposomes), discusses recent therapeutic applications for the topical treatment of different skin disorders and highlights the need for further studies to demonstrate significant clinical benefits of transfersomes compared with conventional therapies.

Advances and challenges in the nanoparticles-laden contact lenses for ocular drug delivery

The delivery of drugs that target ocular tissues is challenging due to the physiological barriers of the eye like tear dilution, nasolacrimal drainage, blinking, tear turnover rate and low residence time Drug-laden contact lenses can be a possible solution to overcome some of these challenges. Nanoparticles are being extensively studied as novel systems for loading drugs into therapeutic contact lenses. The versatile features of the organic and inorganic nanoparticles and their diverse physicochemical properties make it possible to load and sustain drug release from the contact lenses. Nevertheless, several issues remains to be solved before its clinical application and commercialization such as changes in contact lens swelling (water content), transmittance, protein adherence, surface roughness, tensile strength, ion and oxygen permeability and drug leaching during contact lens manufacture. However, clinical studies demonstrated the potential of therapeutic contact lenses to manage the scientific, commercial and regulatory challenges to make its place in the market. This review highlights the different methodologies used to fabricate nanoparticle-laden contact lenses and highlights the major advances and challenges to commercialization.

Recent advances in ophthalmic preparations: Ocular barriers, dosage forms and routes of administration

The human eye is a complex organ with unique anatomy and physiology that restricts the delivery of drugs to target ocular tissues/sites. Recent advances in the field of pharmacy, biotechnology and material science have led to development of novel ophthalmic dosage forms which can provide sustained drug delivery, reduce dosing frequency and improve the ocular bioavailability of drugs. This review highlights the different anatomical and physiological factors which affect ocular bioavailability of drugs and explores advancements from 2016 to 2020 in various ophthalmic preparations. Different routes of drug administration such as topical, intravitreal, intraocular, juxtascleral, subconjunctival, intracameral and retrobulbar are discussed with their advances and limitations.

Emulgel: an effective drug delivery system

BACKGROUND

Emulgels are the emerging drug delivery system nowadays that has become popular for the delivery of hydrophobic drugs. This formulation is considered a novel type of drug delivery system and a mixture of emulsion and gel.

OBJECTIVE

The objective of this review is to throw light on the preparation of emulgels and their evaluation which will conclude how important these dosage forms are. In the coming years, it will be most commonly used because it is easy to use and enhances patient compliance.

CONCLUSION

Emulgels are easily removable, spreadable, thixotropic, greaseless, have a pleasing appearance, emollient, long shelf life, and transparent. In the present era, the emulgels are being used for the delivery of many drugs like analgesics, anti-inflammatory, anti-acne and anti-fungal. Hence, it is of great pharmacological importance and is relatively free of side effects.

Improving the Antitumor Activity and Bioavailability of Sonidegib for the Treatment of Skin Cancer

Throughout the United States and the world, skin cancer is the most frequent form of cancer. Sonidegib (SNG) is a hedgehog inhibitor that has been used for skin cancer treatment. However, SNG has low bioavailability and is associated with resistance. The focus of this work is to enhance bioavailability, anti-tumor efficacy and targeting of SNG via developing ethosome gel as a potential treatment for skin cancer. SNG-loaded ethosomes formulation was prepared and characterized in vitro by %entrapment efficiency (%EE), vesicle size, morphology, %release and steady-state flux. The results showed that the prepared formulation was spherical nanovesicles with a %EE of 85.4 ± 0.57%, a particle size of 199.53 ± 4.51 nm and a steady-state flux of 5.58 ± 0.08 µg/cm2/h. In addition, SNG-loaded ethosomes formulation was incorporated into carbopol gel to study the anti-tumor efficacy, localization and bioavailability in vivo. Compared with oral SNG, the formulation showed 3.18 times higher relative bioavailability and consequently significant anti-tumor activity. In addition, this formulation showed a higher rate of SNG penetration in the skin's deep layers and passive targeting in tumor cells. Briefly, SNG-loaded ethosome gel can produce desirable therapeutic benefits for treatment of skin cancer.

Why do few drug delivery systems to combat neglected tropical diseases reach the market? An analysis from the technology's stages

INTRODUCTION

Many drugs used to combat schistosomiasis, Chagas disease, and leishmaniasis (SCL) have clinical limitations such as: high toxicity to the liver, kidneys and spleen; reproductive, gastrointestinal, and heart disorders; teratogenicity. In this sense, drug delivery systems (DDSs) have been described in the literature as a viable option for overcoming the limitations of these drugs. An analysis of the level of development (TRL) of patents can help in determine the steps that must be taken for promising technologies to reach the market.

AREAS COVERED

This study aimed to analyze the stage of development of DDSs for the treatment of SCL described in patents. In addition, we try to understand the main reasons why many DDSs do not reach the market. In this study, we examined DDSs for drugs indicated by WHO and treatment of SCL, by performing a search for patents.

EXPERT OPINION

In this present work we provide arguments that support the hypothesis that there is a lack of integration between academia and industry to finance and continue research, especially the development of clinical studies. We cite the translational research consortia as the potential alternative for developing DDSs to combat NTDs.