Delivering drugs by the transdermal route: review and comment

Chitosan Nanoparticles: Approaches to Preparation, Key Properties, Drug Delivery Systems, and Developments in Therapeutic Efficacy

The integration of nanotechnology into drug delivery systems holds great promise for enhancing pharmaceutical effectiveness. This approach enables precise targeting, controlled release, improved patient compliance, reduced side effects, and increased bioavailability. Nanoparticles are vital for transporting biomolecules-such as proteins, enzymes, genes, and vaccines-through various administration routes, including oral, intranasal, vaginal, buccal, and pulmonary. Among biodegradable polymers, chitosan, a linear polysaccharide derived from chitin, stands out due to its biocompatibility, safety, biodegradability, mucoadhesive properties, and ability to enhance permeation. Its cationic nature supports strong molecular interactions and provides antimicrobial, anti-inflammatory, and hemostatic benefits. However, its solubility, influenced by pH and ionic sensitivity, poses challenges requiring effective solutions. This review explores chitosan, its modified derivatives and chitosan nanoparticles mainly, focusing on nanoparticles physicochemical properties, drug release mechanisms, preparation methods, and factors affecting their mean hydrodynamic diameter (particle size). It highlights their application in drug delivery systems and disease treatments across various routes. Key considerations include drug loading capacity, zeta potential, and stability, alongside the impact of molecular weight, degree of deacetylation, and drug solubility on nanoparticle properties. Recent advancements and studies underscore chitosan's potential, emphasizing its modified derivatives'versatility in improving therapeutic outcomes.

Chitosan, derivatives, and its nanoparticles: Preparation, physicochemical properties, biological activities, and biomedical applications - A comprehensive review

Chitosan, derived from the deacetylation of chitin, is the second most widely used natural polymer, valued for its nontoxic, biocompatible, and biodegradable properties. These attributes have driven extensive research into diverse applications of chitosan and various derivatives. The key characteristics of chitosan muco-adhesion, permeability enhancement, drug release modulation, and antimicrobial activity are primarily due to its amino and hydroxyl groups. However, the limited solubility of raw chitosan in water and most organic solvents has posed challenges for broader application. Numerous chemically modified derivatives have been developed to address these inadequacies with improved physical and chemical properties. Among these derivatives, chitosan nanoparticles have emerged as versatile drug carriers with precise release kinetics and the capacity for targeted delivery, greatly enhancing drug efficacy and safety profiles for therapeutic applications. Due to these unique physicochemical properties, chitosan and chitosan nanoparticles are promising for improved drug delivery, vaccine administration, transplantation, gene therapy, and diagnostics. This review examines the physicochemical properties and bioactivities of chitosan and chitosan nanoparticles, emphasizing their broad-ranging biomedical applications.

Dimethysiloxane polymer for the effective transdermal delivery of donepezil in Alzheimer's disease treatment

Donepezil (DNZ) has been used to treat dementia associated with mild, moderate, or severe Alzheimer's disease (AD). DNZ uptake can alleviate cognitive symptoms in AD patients via acetylcholinesterase (AChE) inhibition. However, oral administration of DNZ has limitations, including first-pass metabolism, difficulties with swallowing, and low patient compliance. In this work, we disclose a novel transdermal DNZ delivery system utilizing T2 polymer, synthesized via the ring-opening polymerization of 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentane with trifluoroacetic acid (TFA). In the in vivo studies in an AD animal model, the DNZ-loaded T2 polymer (DNZ@T2) facilitated efficient transdermal DNZ delivery to the bloodstream and improved spatial working memory and long-term memory of the AD mouse model. Both the T2 polymer and DNZ@T2 exhibited low cytotoxicity and non-significant in vivo toxicity. This research highlights a promising transdermal delivery strategy for AD treatment, potentially enhancing therapeutic efficacy and patient compliance.

Transethosomes: A Comprehensive Review of Ultra-Deformable Vesicular Systems for Enhanced Transdermal Drug Delivery

The transdermal route is one of the effective routes for delivering drugs. It also overcomes many limitations associated with oral delivery. One of the limitations of this route is the drug's poor skin permeability-stratum corneum, the skin's outermost layer that also acts as a barrier for the drug to penetrate. Traditional liposomal formulation is utilized to overcome these limitations. However, these liposomes also have certain difficulty in delivering drugs across the barriers. Ultra-deformable vesicles are novel vesicular structures that are flexible and stable, they can easily bypass the skin barriers more efficiently and thus enhance bioavailability. These vesicles consist of ethosomes, transethosomes, and transferosomes. Transethosomes are more advanced than other vesicular systems because they contain ethanol, phospholipids, and edge activators, making them more deformable and easier to penetrate deeper skin membranes. These vesicular systems can be prepared by various methods, such as cold, hot, and thin film hydration. Characterization of transethosomes includes vesicular size, zeta potential, polydispersity index and encapsulation efficiency, stability, and drug release studies. These vesicular systems can be utilized to deliver a variety of medications transdermally, including analgesics, antibiotics, and arthritis medications. Despite their promising potential, ethanol-based formulations present several problems requiring additional study. This review aims to describe various vesicular structures that have been used to overcome the barrier for the transdermal delivery of drugs and also describe brief composition, method of preparation, characterization, mechanism of penetration of transethosomes, as well as highlighted various applications of transethosomes in medicine, clinical trials and patents.

Beyond Needles: Immunomodulatory Hydrogel-Guided Vaccine Delivery Systems

Vaccines are critical for combating infectious diseases, saving millions of lives worldwide each year. Effective immunization requires precise vaccine delivery to ensure proper antigen transport and robust immune activation. Traditional vaccine delivery systems, however, face significant challenges, including low immunogenicity and undesirable inflammatory reactions, limiting their efficiency. Encapsulating or binding vaccines within biomaterials has emerged as a promising strategy to overcome these limitations. Among biomaterials, hydrogels have gained considerable attention for their biocompatibility, ability to interact with biological systems, and potential to modulate immune responses. Hydrogels offer a materials science-driven approach for targeted vaccine delivery, addressing the shortcomings of conventional methods while enhancing vaccine efficacy. This review examines the potential of hydrogel-based systems to improve immunogenicity and explores their dual role as immunomodulatory adjuvants. Innovative delivery methods, such as microneedles, patches, and inhalable systems, are discussed as minimally invasive alternatives to traditional administration routes. Additionally, this review addresses critical challenges, including safety, scalability, and regulatory considerations, offering insights into hydrogel-guided strategies for eliciting targeted immune responses and advancing global immunization efforts.

Synthesis of vitamin D3 loaded ethosomes gel to cure chronic immune-mediated inflammatory skin disease: physical characterization, in vitro and ex vivo studies

The purpose of the current work was to develop and characterize ethosomes of vitamin D3 gel that could more effectively work against psoriasis. Psoriasis is a chronic immune-mediated inflammatory skin disease. Due to vitamin D3 role in proliferation and maturation of keratinocytes, it has become an important local therapeutic option in the treatment of psoriasis. In this research we have initiated worked on ethosomes gels containing vitamin D3 to treat psoriasis. Soya lecithin 1-8% (w/v), propylene glycol and ethanol were used to create the formulations, which were then tested for vesicle size, shape, surface morphology, entrapment effectiveness, and in vitro drug permeation. The drug encapsulation efficiency of ethosomes was 96.25% ± 0.3. The particle sizes of the optimized ethosomes was 148 and 657 nm, and the PDI value was 0.770 ± 0.12 along with negative charge - 14 ± 3. Fourier transform infrared (FT-IR) spectroscopy and differential scanning calorimetry (DSC) along with thermogravimetric analysis (TGA) studies confirmed the absence of interactions between vitamin D3 and other ingredients. It was determined that the total amount of medication that penetrated the membrane was 95.34% ± 3. Percentage lysis was very negligible for all strengths which were found less than 15%. Based on our research, ethosomes appear to be safe for use. The vitamin D3 ethosomal gel order, description, pH, and viscosity were all within the specified ranges, according to the findings of a 6-month investigation into the stability profile of the completed system. In this research, we successfully prepared ethosomes loaded with vitamin D3 and then converted it into gel for patients' easy applications.

Advances in Transdermal Delivery of Antimicrobial Peptides for Wound Management: Biomaterial-Based Approaches and Future Perspectives

Antimicrobial peptides (AMPs), distinguished by their cationic and amphiphilic nature, represent a critical frontier in the battle against antimicrobial resistance due to their potent antimicrobial activity and a broad spectrum of action. However, the clinical translation of AMPs faces hurdles, including their susceptibility to degradation, limited bioavailability, and the need for targeted delivery. Transdermal delivery has immense potential for optimizing AMP administration for wound management. Leveraging the skin's accessibility and barrier properties, transdermal delivery offers a noninvasive approach that can circumvent systemic side effects and ensure sustained release. Biomaterial-based delivery systems, encompassing nanofibers, hydrogels, nanoparticles, and liposomes, have emerged as key players in enhancing the efficacy of transdermal AMP delivery. These biomaterial carriers not only shield AMPs from enzymatic degradation but also provide controlled release mechanisms, thereby elevating stability and bioavailability. The synergistic interaction between the transdermal approach and biomaterial-facilitated formulations presents a promising strategy to overcome the multifaceted challenges associated with AMP delivery. Integrating advanced technologies and personalized medicine, this convergence allows the reimagining of wound care. This review amalgamates insights to propose a pathway where AMPs, transdermal delivery, and biomaterial innovation harmonize for effective wound management.

Navigating Skin Delivery Horizon: An Innovative Approach in Pioneering Surface Modification of Ultradeformable Vesicles

In the dynamic landscape of pharmaceutical advancements, the strategic application of active pharmaceutical ingredients to the skin through topical and transdermal routes has emerged as a compelling avenue for therapeutic interventions. This non-invasive approach has garnered considerable attention in recent decades, with numerous attempts yielding approaches and demonstrating substantial clinical potential. However, the formidable barrier function of the skin, mainly the confinement of drugs on the upper layers of the stratum corneum, poses a substantial hurdle, impeding successful drug delivery via this route. Ultradeformable vesicles/carriers (UDVs), positioned within the expansive realm of nanomedicine, have emerged as a promising tool for developing advanced dermal and transdermal therapies. The current review focuses on improving the passive dermal and transdermal targeting capacity by integrating functionalization groups by strategic surface modification of drug-loaded UDV nanocarriers. The present review discusses the details of case studies of different surface-modified UDVs with their bonding strategies and covers the recent patents and clinical trials. The design of surface modifications holds promise for overcoming existing challenges in drug delivery by marking a significant leap forward in the field of pharmaceutical sciences.

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.

Systemic Anti-Inflammatory Agents in the Prevention of Chemoradiation-Induced Mucositis: A Review of Randomised Controlled Trials

Mucositis is a pathological condition characterised by inflammation and ulceration of the mucous membranes lining the alimentary canal, particularly in the mouth (oral mucositis) and the gastrointestinal tract. It is a common side effect of cancer treatments, including chemotherapy and radiotherapy, and it is sometimes responsible for treatment interruptions. Preventing mucositis throughout the alimentary tract is therefore crucial. However, current interventions mainly target either oral or gastrointestinal side effects. This review aimed to investigate the use of systemically administered anti-inflammatory agents to prevent mucositis in cancer patients undergoing cancer treatment. PubMed, Ovid, Scopus, Web of Science, WHO ICTRP and ClinicalTrials.gov were screened to identify eligible randomised controlled trials (RCTs). The published literature on anti-inflammatory agents provides mixed evidence regarding the degree of efficacy in preventing/reducing the severity of mucositis in most anticancer treatments; however, sample size continued to be a significant limitation, alongside others discussed. Our review yielded a list of several anti-inflammatory agents that exhibit potential mucositis-preventive effects in cancer patients undergoing cancer treatment, which can be used to inform clinical practice.

Tailoring of Bilosomal Nanogel for Augmenting the Off-Label Use of Sildenafil Citrate in Pediatric Pulmonary Hypertension

Pediatric pulmonary hypertension is a serious syndrome with significant morbidity and mortality. Sildenafil is widely used off-label in pediatric patients with pulmonary arterial hypertension. In this study, bile salt-stabilized nanovesicles (bilosomes) were screened for their efficacy to enhance the transdermal delivery of the phosphodiesterase type 5 inhibitor, sildenafil citrate, in an attempt to augment its therapeutic efficacy in pediatric pulmonary hypertension. A response surface methodology was implemented for fabricating and optimizing a bilosomal formulation of sildenafil (SDF-BS). The optimized SDF-BS formulation was characterized in terms of its entrapment efficiency (EE), zeta potential, vesicle size, and in vitro release profile. The optimized formula was then loaded onto hydroxypropyl methyl cellulose (HPMC) hydrogel and assessed for skin permeation, in vivo pharmacokinetics, and pharmacodynamic studies. The optimized SDF-BS showed the following characteristic features; EE of 88.7 ± 1.1%, vesicle size of 185.0 + 9.2 nm, zeta potential of -20.4 ± 1.1 mV, and efficiently sustained SDF release for 12 h. Skin permeation study revealed a remarkable improvement in SDF penetration from bilosomal gel compared to plain SDF gel. In addition, pharmacokinetic results revealed that encapsulating SDF within bilosomal vesicles significantly enhanced its systemic bioavailability (∼3 folds), compared to SDF oral suspension. In addition, pharmacodynamic investigation revealed that, compared to plain SDF gel or oral drug suspension, SDF-BS gel applied topically triggered a significant elevation (p < 0.05) in cGMP serum levels, underscoring the superior therapeutic efficacy of SDF-BS gel. Conclusively, bilosomes can be viewed as a promising nanocarrier for transdermal delivery of SDF that would grant higher therapeutic efficiency while alleviating the limitations encountered with SDF oral administration.

Bioinspired and Multifunctional Tribological Materials for Sliding, Erosive, Machining, and Energy-Absorbing Conditions: A Review

Friction, wear, and the consequent energy dissipation pose significant challenges in systems with moving components, spanning various domains, including nanoelectromechanical systems (NEMS/MEMS) and bio-MEMS (microrobots), hip prostheses (biomaterials), offshore wind and hydro turbines, space vehicles, solar mirrors for photovoltaics, triboelectric generators, etc. Nature-inspired bionic surfaces offer valuable examples of effective texturing strategies, encompassing various geometric and topological approaches tailored to mitigate frictional effects and related functionalities in various scenarios. By employing biomimetic surface modifications, for example, roughness tailoring, multifunctionality of the system can be generated to efficiently reduce friction and wear, enhance load-bearing capacity, improve self-adaptiveness in different environments, improve chemical interactions, facilitate biological interactions, etc. However, the full potential of bioinspired texturing remains untapped due to the limited mechanistic understanding of functional aspects in tribological/biotribological settings. The current review extends to surface engineering and provides a comprehensive and critical assessment of bioinspired texturing that exhibits sustainable synergy between tribology and biology. The successful evolving examples from nature for surface/tribological solutions that can efficiently solve complex tribological problems in both dry and lubricated contact situations are comprehensively discussed. The review encompasses four major wear conditions: sliding, solid-particle erosion, machining or cutting, and impact (energy absorbing). Furthermore, it explores how topographies and their design parameters can provide tailored responses (multifunctionality) under specified tribological conditions. Additionally, an interdisciplinary perspective on the future potential of bioinspired materials and structures with enhanced wear resistance is presented.

Assessing the Efficacy of Berberine Hydrochloride-loaded Transethosomal Gel System in Treating Dermatophytosis Caused by Trichophyton rubrum in ex-vivo, in-vitro and in-vivo Models

BACKGROUND

Dermatophytosis is the most common dermatological disorder worldwide. Many drugs are available in the market for the treatment of dermatophytosis, but they have had limited success due to the stratum corneum barrier, antifungal resistance, drug permeation, drug retention in skin layers, etc. Thus, there is a constant need for new topical compounds that are effective against dermatophytosis. Berberine-hydrochloride is an attractive candidate to become an antifungal drug, and by using nanotechnology, it achieves deeper penetration in skin layers with enhanced permeability through the stratum corneum.

METHODS

In this study, we developed an oleic acid-containing berberine-hydrochloride-loaded transethosomal gel for effective treatment of dermatophytosis by Trichophyton rubrum. Berberine- hydrochloride-loaded transethosomal gels were fabricated using the hot homogenization method, followed by the incorporation of transethosomes into the gel-based system using carbopol 934. Transethosomal gel was characterized by physicochemical properties, in vitro drug release, ex-vivo permeation studies, CLSM visualization, antifungal activity, histopathological evaluation, and dermatokinetic study.

RESULTS

Berberine-hydrochloride-loaded transethosomes seemed to be spherical and found in a range between 200-300 nm. Berberine-hydrochloride-loaded transethosomal gel formulation also exhibited controlled ex-vivo permeation of berberine-hydrochloride over 24 hr through excised rat skin, and CLSM confirmed deeper penetration into skin layers. The in vivo study revealed that transethosomal gel had a healing effect on the skin of Wistar rats infected with Trichophyton rubrum and was better than luliconazole cream. The histopathological evaluation confirmed its safety, and the dermatokinetic study showed transethosomal gel superiority over marketed cream.

CONCLUSION

Therefore, the incorporation of berberine hydrochloride-loaded transethosomal nanosystems into the gel has the potential to enhance antifungal activity and permeation through transdermal drug delivery.

Date Palm Extract (Phoenix dactylifera) Encapsulated into Palm Oil Nanolipid Carrier for Prospective Antibacterial Influence

It is worthwhile to note that using natural products today has shown to be an effective strategy for attaining the therapeutic goal with the highest impact and the fewest drawbacks. In Saudi Arabia, date palm (Phoenix dactylifera) is considered the principal fruit owing to its abundance and incredible nutritional benefits in fighting various diseases. The main objective of the study is to exploit the natural products as well as the nanotechnology approach to obtain great benefits in managing disorders. The present investigation focused on using the powder form of date palm extract (DPE) of Khalas cultivar and incorporates it into a nanolipid formulation such as a nanostructured lipid carrier (NLC) prepared with palm oil. Using the quality by design (QbD) methodology, the most optimized formula was chosen based on the number of assigned parameters. For more appropriate topical application, the optimized DP-NLC was combined with a pre-formulated hydrogel base forming the DP-NLC-hydrogel. The developed DP-NLC-hydrogel was evaluated for various physical properties including pH, viscosity, spreadability, and extrudability. Additionally, the in vitro release of the formulation as well as its stability upon storage under two different conditions of room temperature and refrigerator were investigated. Eventually, different bacterial strains were utilized to test the antibacterial efficacy of the developed formulation. The optimized DP-NLC showed proper particle size (266.9 nm) and in vitro release 77.9%. The prepared DP-NLC-hydrogel showed acceptable physical properties for topical formulation, mainly, pH 6.05, viscosity 9410 cP, spreadability 57.6 mm, extrudability 84.5 (g/cm2), and in vitro release 42.4%. Following three months storage under two distinct conditions, the formula exhibited good stability. Finally, the antibacterial activity of the developed DP-NLC-hydrogel was evaluated and proved to be efficient against various bacterial strains.

Development of a Microfluidic Formatted Ultrasound-Controlled Monodisperse Lipid Vesicles' Hydrogel Dressing Combined with Ultrasound for Transdermal Drug Delivery System

Transdermal drug delivery system (TDDS) has attracted much attention in the pharmaceutical technology area. However, the current methods are difficult to ensure penetration efficiency, controllability, and safety in the dermis, so its widespread clinical use has been limited. This work proposes an ultrasound-controlled monodisperse lipid vesicles (U-CMLVs) hydrogel dressing, which combines with ultrasound to form TDDS. Using microfluidic technology, prepare size controllable U-CMLVs with high drug encapsulation efficiency and quantitative encapsulation of ultrasonic response materials, and even uniform mix them with hydrogel to prepare the required thickness of dressings. The high encapsulation efficiency can ensure sufficient dosage of the drugs and further realize the control of ultrasonic response through quantitative encapsulation of ultrasound-responsive materials. Using high frequency (5 MHz, 0.4 W cm-2 ) and low frequency (60 kHz, 1 W cm-2 ) ultrasound to control the movement and rupture of U-CMLVs, the contents not only penetrate the stratum corneum into the epidermis but also break through the bottleneck of penetration efficiency, and deep into the dermis. These findings provide the groundwork for deep, controllable, efficient, and safe drug delivery through TDDS and lay a foundation for further expanding its application.

A shea butter-based ketamine ointment: The antidepressant effects of transdermal ketamine in rats

The delayed onset of monoaminergic antidepressants and disadvantages of traditional administration routes created the need for alternative non-invasive delivery methods with rapid onset therapeutic effect. Ketamine attracted attention as a fast-acting glutamatergic antidepressant with ideal physiochemical properties for alternative routes of administration. However, there is no sufficient data for its transdermal use in depression. In this proof-of-concept study, we investigated the antidepressant effects of transdermal ketamine delivered via a novel ointment with skin protective, emulsifying and permeation enhancing properties. A shea butter-based 5% (w/w) ketamine ointment or a drug-free vehicle ointment were applied to the shaved dorsal skin of male Wistar rats for 2 days, twice a day. Behavioral despair, locomotor activity and anxiety-like behavior were respectively assessed in the forced swim test (FST), open field test (OFT), and elevated plus maze (EPM). The pharmacokinetic profile of the ointment was analyzed with high-performance liquid chromatography. Transdermal ketamine ameliorated behavioral despair without altering general locomotor activity and anxiety-like behavior, showing that skin-friendly drug carriers like shea butter may constitute promising alternatives to current routes of delivery for ketamine. Tested transdermal method aims to provide more sustainable drug delivery for long-term treatment schedules. Future studies can investigate its long-term use, side effects and abuse liability.

Exploring the Versatility of Microemulsions in Cutaneous Drug Delivery: Opportunities and Challenges

Microemulsions are novel drug delivery systems that have garnered significant attention in the pharmaceutical research field. These systems possess several desirable characteristics, such as transparency and thermodynamic stability, which make them suitable for delivering both hydrophilic and hydrophobic drugs. In this comprehensive review, we aim to explore different aspects related to the formulation, characterization, and applications of microemulsions, with a particular emphasis on their potential for cutaneous drug delivery. Microemulsions have shown great promise in overcoming bioavailability concerns and enabling sustained drug delivery. Thus, it is crucial to have a thorough understanding of their formulation and characterization in order to optimize their effectiveness and safety. This review will delve into the different types of microemulsions, their composition, and the factors that affect their stability. Furthermore, the potential of microemulsions as drug delivery systems for skin applications will be discussed. Overall, this review will provide valuable insights into the advantages of microemulsions as drug delivery systems and their potential for improving cutaneous drug delivery.

Potential of Lipid-Based Nanocarriers against Two Major Barriers to Drug Delivery-Skin and Blood-Brain Barrier

Over the past few years, pharmaceutical and biomedical areas have made the most astounding accomplishments in the field of medicine, diagnostics and drug delivery. Nanotechnology-based tools have played a major role in this. The implementation of this multifaceted nanotechnology concept encourages the advancement of innovative strategies and materials for improving patient compliance. The plausible usage of nanotechnology in drug delivery prompts an extension of lipid-based nanocarriers with a special reference to barriers such as the skin and blood-brain barrier (BBB) that have been discussed in the given manuscript. The limited permeability of these two intriguing biological barriers restricts the penetration of active moieties through the skin and brain, resulting in futile outcomes in several related ailments. Lipid-based nanocarriers provide a possible solution to this problem by facilitating the penetration of drugs across these obstacles, which leads to improvements in their effectiveness. A special emphasis in this review is placed on the composition, mechanism of penetration and recent applications of these carriers. It also includes recent research and the latest findings in the form of patents and clinical trials in this field. The presented data demonstrate the capability of these carriers as potential drug delivery systems across the skin (referred to as topical, dermal and transdermal delivery) as well as to the brain, which can be exploited further for the development of safe and efficacious products.

Dissolvable microneedles for transdermal drug delivery showing skin pentation and modified drug release

Topical therapies for chronic skin diseases suffer from a low patient compliance due to the inconvenient treatment regimens of available products. Dissolvable microneedles (MN) with modified release offer an interesting possibility to increase the compliance by acting as a depot in the skin and thereby decreasing the dosing frequency. Furthermore, the bioavailability can be increased significantly by bypassing the barrier of the skin by the direct penetration of the MN into the skin. In this study the depot effect and skin penetration of an innovative dissolvable MN patch was assessed by insertion in ex vivo human skin and in vivo using minipigs. The MN patches are based on biodegradable polymers and the active pharmaceutical ingredients calcipotriol (Calci) and betamethasone-17-21-dipropionate (BDP) used to treat psoriasis. Using computed tomography (CT) and Coherent anti-Stokes Raman scattering (CARS) microscopy it was possible to visualize the skin penetration and follow the morphology of the MN as function of time in the skin. The depot effect was assessed by studying the modified in vitro release in an aqueous buffer and by comparing the drug release of a single application of a patch both ex vivo and in vivo to daily application of a marketed oleogel containing the same active pharmaceutical ingredients. The CT and CARS images showed efficient penetration of the MN patches into the upper dermis and a slow swelling process of the drug containing tip over a period of 8 days. Furthermore, CARS demonstrated that it can be used as a noninvasive technique with potential applicability in clinical settings. The in vitro release studies show a release of 54% over a time period of 30 days. The pharmacological relevance of MNs was confirmed in human skin explants and in vivo after single application and showed a similar response on calcipotriol and BDP mediated signaling events compared to daily application of the active oleogel. Altogether it was demonstrated that the MN can penetrate the skin and have the potential to provide a depot effect.

Preparation and Evaluation of Vitamin D3 Supplementation as Transdermal Film-Forming Solution

Vitamin D3 is available in oral and injectable dosage forms. Interest in the transdermal route as an alternative to the oral and parenteral routes has grown recently. In this study, several film-forming solutions for the transdermal delivery of vitamin D3 were prepared. They contained 6000 IU/mL of vitamin D3 that formed a dry and acceptable film in less than 5 min after application. The formulations consisted of ethanol and acetone 80:20, and one or more of the following ingredients: Eudragit L100-55, PVP, PG, limonene, oleic acid, camphor, and menthol. Vitamin D3 release was studied from both the film-forming solution and pre-dried films using a Franz diffusion cell. The film-forming solution released a significant amount of vitamin D3 compared to the dry film, which is attributed mostly to the saturation driving force due to the evaporation of volatile solvents. In vitro permeation studies through artificial skin Strat M® membrane revealed that the cumulative amount of vitamin D3 permeated after 24 h under the experimental conditions was around 800 IU across 3.14 cm2. The cumulative permeation curve showed faster permeation in earlier stages. Young's modulus, viscosity, and pH of the formulations were determined. Most of the formulations were stable for 3 weeks.

Therapeutic Potential of Controlled Delivery Systems in Asthma: Preclinical Development of Flavonoid-Based Treatments

Asthma is a chronic disease with increasing prevalence and incidence, manifested by allergic inflammatory reactions, and is life-threatening for patients with severe disease. Repetitive challenges with the allergens and limitation of treatment efficacy greatly dampens successful management of asthma. The adverse events related to several drugs currently used, such as corticosteroids and β-agonists, and the low rigorous adherence to preconized protocols likely compromises a more assertive therapy. Flavonoids represent a class of natural compounds with extraordinary antioxidant and anti-inflammatory properties, with their potential benefits already demonstrated for several diseases, including asthma. Advanced technology has been used in the pharmaceutical field to improve the efficacy and safety of drugs. Notably, there is also an increasing interest for the application of these techniques using natural products as active molecules. Flavones, flavonols, flavanones, and chalcones are examples of flavonoid compounds that were tested in controlled delivery systems for asthma treatment, and which achieved better treatment results in comparison to their free forms. This review aims to provide a comprehensive understanding of the development of novel controlled delivery systems to enhance the therapeutic potential of flavonoids as active molecules for asthma treatment.

Development of Capsaicin-Containing Analgesic Silicone-Based Transdermal Patches

Transdermal therapeutic systems (TTSs) enable convenient dosing in drug therapy. Modified silicone-polymer-based patches are well-controlled and cost-effective matrix diffusion systems. In the present study, we investigated the substance release properties, skin penetration, and analgesic effect of this type of TTS loaded with low-dose capsaicin. Release properties were measured in Franz diffusion cell and continuous flow-through cell approaches. Capsaicin was detected with HPLC-UV and UV spectrophotometry. Raman spectroscopy was conducted on human skin samples exposed to the TTS. A surgical incision or carrageenan injection was performed on one hind paw of male Wistar rats. TTSs were applied to the epilated dorsal skin. Patches were kept on the animals for 6 h. The thermal hyperalgesia and mechanical pain threshold of the hind paws were detected. Patches exhibited controlled, zero-order kinetic capsaicin release. According to the Raman mapping, capsaicin penetrated into the epidermis and dermis of human skin, where the target receptors are expressed. The thermal pain threshold drop of the operated rat paws was reversed by capsaicin treatment compared to that of animals treated with control patches. It was concluded that our modified silicone-polymer-based capsaicin-containing TTS is suitable for the relief of traumatic and inflammatory pain.

Development of a Silicone-Based Polymer Matrix as a Suitable Transdermal Therapeutic System for Diallyl Disulfide

There is an unmet need for novel therapeutic tools relieving chronic pain. Hydrogen sulfide (H₂S) is highly involved in pain processes; however, the development of ideal matrices for sulfide donor compounds remains a great pharmaceutical challenge. We aimed to establish a suitable transdermal therapeutic system (TTS) using the H₂S donor diallyl disulfide (DADS) as a model compound. After the preparation of DADS, its solubility was investigated in different liquid excipients (propylene glycol, polyethylene glycol, silicone oil) and its membrane diffusivity was assessed in silicone matrices of different compositions. Drug-releasing properties of DADS-containing patches with different silicone oil contents were determined with Franz and flow-through cells. We found a correlation between the liquid excipient content of the patch and the diffusion rate of DADS. DADS showed the best solubility in dimethyl silicone oil, and the diffusion constant was proportional to the amount of oil above the 3 m/m% threshold value. The 8-day-old patch showed a significantly lower, but better-regulated, drug release over time than the 4-day-old one. In conclusion, the silicone-based polymer matrix developed in this study is suitable for stable storage and optimal release of DADS, providing a good basis for a TTS applied in chronic pain.

Effect of Polymers and Permeation Enhancers in the Release of Quetiapine Fumarate Transdermal Patch through the Dialysis Membrane

Quetiapine Fumarate is potent, and the daily therapeutic dose can be delivered easily across the skin with the help of permeation enhancers. Quetiapine Fumarate-loaded transdermal patches were prepared by solvent evaporation technique. Various formulation parameters, excipients, and their combinations were optimized to get thin, translucent, smooth, stable, and high permeable character patches. A total number of 10 formulations were prepared. All formulations were subjected to various physicochemical evaluations. Three different formulations were prepared and F1, F2, and F3. Various physicochemical studies were carried out and found no significant difference between the three batches. The in vitro release study showed 74.29%, 82.73%, and 77.27%, respectively, up to 24 h. From the results, F2 has been selected as an optimized formulation and evaluated for skin irritation test. The results revealed that there is no irritation produced. The stability study results showed that there is no significant change from its initial nature till the period of three months in both temperatures. Quetiapine Fumarate Transdermal Patch F2 has achieved the goal of extended-release, cost-effectiveness, lowering the dose and frequency of drug administration, and thus may improve patient compliance.

Antifungal Cationic Nanoemulsion Ferrying Miconazole Nitrate with Synergism to Control Fungal Infections: In Vitro, Ex Vivo, and In Vivo Evaluations

This study aimed to deliver a cationic nanoemulsion carrying miconazole nitrate (MCN) to control fungal infections using excipients for synergism. Peceol (oil) and labrasol (surfactant) were selected based on maximum solubility and zone of inhibition values against Candida albicans and Aspergillus niger. Optimized MCNE11 was evaluated [size, zeta potential, % entrapment efficiency (%EE), % transmittance, viscosity, refractive index, extrudability, polydispersity (PDI), morphology, and pH]. An in vitro drug release study was conducted for comparison between DS (drug suspension) and MNE11. In vitro hemolysis was studied at two different concentrations (0.625 and 2.5 μg/mL). Permeation profiles were generated using rat skin. A Draize test was conducted using rabbit to negate irritability issues. Finally, a stability test of MCNE11 was conducted for 12 months. The results showed that MCNE11 (cationic) was the most optimized in term of size, %EE, and PDI. The drug release from MCNE11 was higher compared to DS but comparable to MNE11 (anionic), suggesting no impact of the imposed cationic charge on the release behavior. Moreover, permeation parameters of MCNE11 were significantly (p < 0.05) greater than MNE11, which may be attributed to the combined impact of size (low), surfactant (for reversible changes), and electrostatic interaction (nanoglobules-skin surface). Thus, stable MCN11 possessing high %EE (89.8%), low size (145 nm), maximum flux (5.7 ± 0.1 μg/cm²/h), high drug deposition (932.7 ± 41.6 μg/cm²), optimal viscosity (44.17 ± 0.8 cP), low PDI (0.21), optimal zeta potential (+28.1 mV), and low hemolysis can be promising alternatives to conventional cream to control resistant and recurring types of fungal infections.

The Transdermal Delivery of Therapeutic Cannabinoids

Recently, several studies have indicated an increased interest in the scientific community regarding the application of Cannabis sativa plants, and their extracts, for medicinal purposes. This plant of enormous medicinal potential has been legalised in an increasing number of countries globally. Due to the recent changes in therapeutic and recreational legislation, cannabis and cannabinoids are now frequently permitted for use in clinical settings. However, with their highly lipophilic features and very low aqueous solubility, cannabinoids are prone to degradation, specifically in solution, as they are light-, temperature-, and auto-oxidation-sensitive. Thus, plant-derived cannabinoids have been developed for oral, nasal-inhalation, intranasal, mucosal (sublingual and buccal), transcutaneous (transdermal), local (topical), and parenteral deliveries. Among these administrations routes, topical and transdermal products usually have a higher bioavailability rate with a prolonged steady-state plasma concentration. Additionally, these administrations have the potential to eliminate the psychotropic impacts of the drug by its diffusion into a nonreactive, dead stratum corneum. This modality avoids oral administration and, thus, the first-pass metabolism, leading to constant cannabinoid plasma levels. This review article investigates the practicality of delivering therapeutic cannabinoids via skin in accordance with existing literature.

Recent Advances in Drug Design and Delivery Across Biological Barriers using Computational Models

Abstract:

The systemic delivery of pharmacological substances generally exhibits several significant limitations associated with the bio-distribution of active drugs in the body. As per consequence, human body’s defense mechanisms become impediments to drug delivery. Various technologies to overcome these limitations have been evolved including computational approaches and advanced drug delivery. As the body of human has evolved to defend itself from hostile biological as well as chemical invaders, along with that these biological barriers such as ocular barriers, blood-brain barriers, intestinal and skin barriers also limit the passage of drugs across desired sites. Therefore, efficient delivery remains an utmost challenge for researchers and scientists. The present review focuses on the techniques to deliver the drugs with efficient therapeutic efficacy at the targeted sites. This review article considered the insights into main biological barriers along with the application of computational or numerical methods dealing with different barriers by determining the drug flow, temperature and various other parameters. It also summarizes the advanced implantable drug delivery system to circumvent the inherent resistance showed by these biological barriers and in turn to improve the drug delivery.

Layer-by-Layer Assembly of Lipid Nanobubbles on Microneedles for Ultrasound-Assisted Transdermal Drug Delivery

Microneedles as a typical device for transdermal drug delivery provide an alternative route for drug administration with minimal digestion by organs and better patient compliance. However, diffusion of passively released drug molecules within the skin tissue mainly depends on the interstitial fluid, which may be affected by different physiological conditions of individuals. Herein, we propose a nanobubble-modified microneedle patch for ultrasound-assisted drug delivery, which provides additional driving force for penetration and diffusion of the drug molecules. Layer-by-layer self-assembled drug-containing nanobubbles on the surfaces of microneedles trigger active drug release upon application of ultrasound. The concomitant microstreaming caused by cavitation effects facilitates the penetration and diffusion of drug molecules in the gelatin gel model and the ex vivo porcine skin model. The proposed drug delivery strategy holds great promise for rapid transdermal drug delivery with enhanced penetration and diffusion of the released drugs.

A Skin-Interfaced, Miniaturized Microfluidic Analysis and Delivery System for Colorimetric Measurements of Nutrients in Sweat and Supply of Vitamins Through the Skin

Nutrients play critical roles in maintaining core physiological functions and in preventing diseases. Technologies for delivering these nutrients and for monitoring their concentrations can help to ensure proper nutritional balance. Eccrine sweat is a potentially attractive class of biofluid for monitoring purposes due to the ability to capture sweat easily and noninvasively from nearly any region of the body using skin-integrated microfluidic technologies. Here, a miniaturized system of this type is presented that allows simple, rapid colorimetric assessments of the concentrations of multiple essential nutrients in sweat, simultaneously and without any supporting electronics - vitamin C, calcium, zinc, and iron. A transdermal patch integrated directly with the microfluidics supports passive, sustained delivery of these species to the body throughout a period of wear. Comparisons of measurement results to those from traditional lab analysis methods demonstrate the accuracy and reliability of this platform. On-body tests with human subjects reveal correlations between the time dynamics of concentrations of these nutrients in sweat and those of the corresponding concentrations in blood. Studies conducted before and after consuming certain foods and beverages highlight practical capabilities in monitoring nutritional balance, with strong potential to serve as a basis for guiding personalized dietary choices.

The influence of edema on the bisoprolol blood concentration after bisoprolol dermal patch application: A case-control study

BACKGROUND

Beta-blocking is important for critically ill patients. Although some patients are required to continue taking beta-blockers after they no longer need critical care, some of these patients have impaired swallowing abilities. Bisoprolol dermal patches have recently been introduced and appear to be a good alternative to oral bisoprolol tablets. However, it is still unclear whether the pharmacodynamics of such patches are affected by edema in patients who have experienced critical care. This study aimed to clarify the effects of systemic edema on beta-blocker absorption from dermal patches in critically ill patients.

METHOD

Patients who exhibited tachycardia and impaired swallowing function after critical care were included in this study. They were assigned to either the edema group (n = 6) or no edema group (n = 6) depending on the presence/absence of edema in the lower extremities. A bisoprolol dermal patch was pasted onto each subject, and the blood bisoprolol concentration was checked at 8 timepoints over the next 24 hours. The area under the serum concentration time curve, maximum concentration observed (Cmax), and time of maximum concentration observed were also examined.

RESULT

The mean blood bisoprolol concentrations of the 2 groups were not significantly different at 2, 4, 6, 8, 10, 12, 16, or 24 hours after the patch application. The area under the serum concentration time curve and maximum concentration observed were not different between the groups. The mean heart rates of the 2 groups were not significantly different at 6, 12, or 24 hours after the patch application (Student t test, P = .0588, P = .1080, and P = .2322, respectively).

CONCLUSION

In this study, the blood concentration of bisoprolol and its heart rate-reducing effects after bisoprolol dermal patch application might not be affected by systemic edema in the lower extremities.

Pharmaceutical Perspective in Wearable Drug Delivery Systems

Humans have been dealing with health problems for millions of years. Normal health services need well-trained personnel and high-cost diagnostic tests, which forces patients to go to hospitals if medical treatment is required. To address this, prototype testing has been carried out into the wearable drug delivery health care perspectives. Researchers have devised a wide variety of formulations for the treatment of various diseases at home by performing real-time monitoring of different routes of drug administration such as ocular, transdermal, intraoral, intracochlear, and several more. A comprehensive review of the different types of wearable drug delivery systems with respect to their manufacturing, mechanism of action and specifications has been done. In the pharmaceutical context, these devices are technologically well-equipped interfaces for diverse physicochemical signals. Above mentioned information with a broader perspective has also been discussed in this article. Several wearable drug delivery systems have been introduced in the market in recent years. But a lot of testing needs to be conducted to address the numerous obstacles before the wearable devices are successfully launched in the market.

Recent advances in microneedles-mediated transdermal delivery of protein and peptide drugs

Proteins and peptides have become a significant therapeutic modality for various diseases because of their high potency and specificity. However, the inherent properties of these drugs, such as large molecular weight, poor stability, and conformational flexibility, make them difficult to be formulated and delivered. Injection is the primary route for clinical administration of protein and peptide drugs, which usually leads to poor patient's compliance. As a portable, minimally invasive device, microneedles (MNs) can overcome the skin barrier and generate reversible microchannels for effective macromolecule permeation. In this review, we highlighted the recent advances in MNs-mediated transdermal delivery of protein and peptide drugs. Emphasis was given to the latest development in representative MNs design and fabrication. We also summarize the current application status of MNs-mediated transdermal protein and peptide delivery, especially in the field of infectious disease, diabetes, cancer, and other disease therapy. Finally, the current status of clinical translation and a perspective on future development are also provided.

Wearable patch delivery system for artificial pancreas health diagnostic-therapeutic application: A review

The advanced stimuli-responsive approaches for on-demand drug delivery systems have received tremendous attention as they have great potential to be integrated with sensing and multi-functional electronics on a flexible and stretchable single platform (all-in-one concept) in order to develop skin-integration with close-loop sensation for personalized diagnostic and therapeutic application. The wearable patch pumps have evolved from reservoir-based to matrix patch and drug-in-adhesive (single-layer or multi-layer) type. In this review, we presented the basic requirements of an artificial pancreas, surveyed the design and technologies used in commercial patch pumps available on the market and provided general information about the latest wearable patch pump. We summarized the various advanced delivery strategies with their mechanisms that have been developed to date and representative examples. Mechanical, electrical, light, thermal, acoustic and glucose-responsive approaches on patch form have been successfully utilized in the controllable transdermal drug delivery manner. We highlighted key challenges associated with wearable transdermal delivery systems, their research direction and future development trends.

Multimodal imaging of drug and excipients in rat lungs following an inhaled administration of controlled-release drug laden PLGA microparticles

Controlled-release formulations, in the form of micro- or nanoparticles, are increasingly attractive to the pharmaceutical industry for drug delivery. For respiratory illnesses, controlled-release microparticle formulations provide an opportunity to deliver a higher percentage of an inhaled medicament dose to the lung, thus potentially reducing the therapeutic dose, frequency of dosing, and minimising side-effects. We describe the use of a multimodal approach consisting of MALDI MS imaging, 3D depth profiling TOF-SIMS analysis, and histopathology to monitor the distribution of drug and excipients in sections taken from excised rat lungs following an inhaled administration of drug-laden microparticles. Following a single dose, the administered drug was detected in the lung via both MALDI MS and TOF-SIMS over a range of time points. Both imaging techniques enabled the characterisation of the distribution and retention of drug particles and identified differences in the capabilities of both imaging modalities. Histochemical staining of consecutive sections was used to provide biological context to the findings and will also be discussed in this presentation. We demonstrate how this multimodal approach could be used to help increase our understanding of the use of controlled release microparticles.

Microneedles in Smart Drug Delivery

Significance: In biomedical setup, at large, and drug delivery, in particular, transdermal patches, hypodermal needles, and/or dermatological creams with the topical appliance are among the most widely practiced routes for transdermal drug delivery. Owing to the stratum corneum layer of the skin, traditional drug delivery methods are inefficient, and the effect of the administered therapeutic cues is limited. Recent Advances: The current advancement at the microlevel and nanolevel has revolutionized the drug delivery sector. Particularly, various types of microneedles (MNs) are becoming popular for drug delivery applications because of safety, patient compliance, and smart action. Critical Issues: Herein, we reviewed state-of-the-art MNs as a smart and sophisticated drug delivery approach. Following a brief introduction, the drug delivery mechanism of MNs is discussed. Different types of MNs, that is, solid, hollow, coated, dissolving, and hydrogel forming, are discussed with suitable examples. The latter half of the work is focused on the applied perspective and clinical translation of MNs. Furthermore, a detailed overview of clinical applications and future perspectives is also included in this review. Future Directions: Regardless of ongoing technological and clinical advancement, the focus should be diverted to enhance the efficacy and strength of MNs. Besides, the possible immune response or interference should also be avoided for successful clinical translation of MNs as an efficient drug delivery system.

Targeted drug delivery strategies for precision medicines

Progress in the field of precision medicine has changed the landscape of cancer therapy. Precision medicine is propelled by technologies that enable molecular profiling, genomic analysis, and optimized drug design to tailor treatments for individual patients. Although precision medicines have resulted in some clinical successes, the use of many potential therapeutics has been hindered by pharmacological issues, including toxicities and drug resistance. Drug delivery materials and approaches have now advanced to a point where they can enable the modulation of a drug's pharmacological parameters without compromising the desired effect on molecular targets. Specifically, they can modulate a drug's pharmacokinetics, stability, absorption, and exposure to tumours and healthy tissues, and facilitate the administration of synergistic drug combinations. This Review highlights recent progress in precision therapeutics and drug delivery, and identifies opportunities for strategies to improve the therapeutic index of cancer drugs, and consequently, clinical outcomes.

Nanochitosan: Commemorating the Metamorphosis of an ExoSkeletal Waste to a Versatile Nutraceutical

Chitin (poly-N-acetyl-D-glucosamine) is the second (after cellulose) most abundant organic polymer. In its deacetylated form-chitosan-becomes a very interesting material for medical use. The chitosan nano-structures whose preparation is described in this article shows unique biomedical value. The preparation of nanochitosan, as well as the most vital biomedical applications (antitumor, drug delivery and other medical uses), have been discussed in this review. The challenges confronting the progress of nanochitosan from benchtop to bedside clinical settings have been evaluated. The need for inclusion of nano aspects into chitosan research, with improvisation from nanotechnological inputs has been prescribed for breaking down the limitations. Future perspectives of nanochitosan and the challenges facing nanochitosan applications and the areas needing research focus have been highlighted.

Optimization of propofol loaded niosomal gel for transdermal delivery

Propofol is an oily liquid widely used for rapid onset of anaesthesia via intravenous route, which shows major limitations of hypersensitivity, anaphylactic reactions and pain. The aim of the present work was to bypass the above issues by formulating tailored niosomal gel to deliver propofol via non-invasive transdermal route. The niosomes were prepared by film hydration method and sonication using cholesterol and Span 80. The Box Behnken design (BBD) was applied to optimize the size (93.5 nm) and the entrapment efficacy (81.5%) of the niosomes by selecting cholesterol at 139 mg, Span 80 at 0.525% and sonication time at 5.13 min. The scanning electron microscopy image showed spherical shape niosomes with smooth surface without aggregation. The ex vivo release data showed significant improvement in the propofol release (92.2% after 10 h) using niosomes in comparison to the control propofol gel (with 30% methanol) without niosomes (25.3% after 10 h). The in vivo pharmacokinetic parameters in the rat model confirmed the improvement in the relative bioavailability with optimized niosomal gel (relative bioavailability = 12.12) in comparison to the control propofol gel. In conclusion, the niosomal gel offered a potential alternative non-invasive route to deliver propofol for procedural sedation especially in pediatric population.

Biopharmaceutic study and in vivo efficacy of natural and derivatives flavanones formulations

Aim: The development and characterization of nanostructured flavanone formulations (FF) of 1 extracted from Eysenhardtia platycarpa and 1a, 1b, 1c and 1d derivatives by structural modification of 1 as anti-inflammatory candidates for topical treatment of local inflammation. Materials & methods: The FF were physicochemical characterized and the behavior release, skin permeation and, in vivo anti-inflammatory efficacy in the rat model were studied. Results: The FF revealed sustained drug release and showed slow drug penetration in human skin. The FF reduced inflammation in comparison with the standard formulation. Conclusion: The FF could be effective systems for the delivery and controlled release of flavanones on the skin, and the chemical modification of lead molecule 1 improved the efficacy.

Architectured Therapeutic and Diagnostic Nanoplatforms for Combating SARS-CoV-2: Role of Inorganic, Organic, and Radioactive Materials

Although extensive research is being done to combat SARS-CoV-2, we are yet far away from a robust conclusion or strategy. With an increased amount of vaccine research, nanotechnology has found its way into vaccine technology. Researchers have explored the use of various nanostructures for delivering the vaccines for enhanced efficacy. Apart from acting as delivery platforms, multiple studies have shown the application of inorganic nanoparticles in suppressing the growth as well as transmission of the virus. The present review gives a detailed description of various inorganic nanomaterials which are being explored for combating SARS-CoV-2 along with their role in suppressing the transmission of the virus either through air or by contact with inanimate surfaces. The review further discusses the use of nanoparticles for development of an antiviral coating that may decrease adhesion of SARS-CoV-2. A separate section has been included describing the role of nanostructures in biosensing and diagnosis of SARS-CoV-2. The role of nanotechnology in providing an alternative therapeutic platform along with the role of radionuclides in SARS-CoV-2 has been described briefly. Based on ongoing research and commercialization of this nanoplatform for a viral disease, the nanomaterials show the potential in therapy, biosensing, and diagnosis of SARS-CoV-2.

Characterization of microneedles and microchannels for enhanced transdermal drug delivery

Microneedle (MN)-based technologies are currently one of the most innovative approaches that are being extensively investigated for transdermal delivery of low molecular weight drugs, biotherapeutic agents and vaccines. Extensive research reports, describing the fabrication and applications of different types of MNs, can be readily found in the literature. Effective characterization tools to evaluate the quality and performance of the MNs as well as for determination of the dimensional and kinetic properties of the microchannels created in the skin, are an essential and critical part of MN-based research. This review paper provides a comprehensive account of all such tools and techniques.