Statistically optimized fast dissolving microneedle transdermal patch of meloxicam: A patient friendly approach to manage arthritis

Design and formulation of fast-dissolving microneedles for the rapid transdermal delivery of lorazepam

This study investigates lorazepam-loaded dissolving microneedles (LMNs) as a fast-acting and minimally invasive treatment for status epilepticus. The LMNs were developed using a micro-moulding technique with an optimised combination of PVP K30, Dextran 40 and Pullulan. Their stability was confirmed through Fourier transform infra-red (FTIR) spectroscopy and X-ray diffraction (XRD) analysis. The Parafilm® membrane insertion test demonstrated 100% penetration efficiency, verifying their ability to effectively pierce the skin. Scanning electron microscopy (SEM) imaging revealed well-defined microneedles with precise dimensions (800 µm height, 200 µm base and 500 µm pitch). The LMNs rapidly dissolved in the subdermal layer of porcine skin. An ex vivo drug diffusion study showed that 3-5% of the encapsulated lorazepam was released within 30 min, with a cumulative release of 79.3% over 24 h. An acute dermal irritation study confirmed the biocompatibility and skin tolerance of the LMNs. Additionally, an in vivo anti-convulsant efficacy study in Albino Wistar rats subjected to maximal electroshock seizures demonstrated significant anticonvulsant effects (p < .05), confirming efficient systemic delivery of lorazepam. These findings highlight LMNs as a rapid-acting, non-invasive transdermal drug delivery system for managing status epilepticus, particularly in ambulatory care settings.

Innovative nanocarriers in arthritis therapy: the role of herbal cubosomes

BACKGROUND

Both osteoarthritis (OA) and rheumatoid arthritis (RA) are long-lasting inflammatory disorders that impact the joints. While conventional treatments like NSAIDs and DMARDs are effective, they often have adverse side effects.

OBJECTIVE

The aim of this review is to explore the possibilities of using herbal treatments in treating the symptoms of arthritis, their stability and bioavailability. Traditional therapies often lead to adverse side effects, prompting a search for safer alternatives, particularly in herbal medicines. This review explores the innovative use of herbal cubosomes as advanced nanocarriers for arthritis therapy. Cubosomes, a type of self-assembled lipid nanoparticle, exhibit unique structural characteristics that enhance the delivery and bioavailability of encapsulated herbal compounds.

METHOD

Access was gained to PubMed, Scopus database, Google Scholar and Web of Science for the literature search. The results were later screened according to the titles, abstracts, and availability of full texts.

RESULTS

The expository evaluation of the literature revealed that Key herbal components, such as Withania somnifera (Ashwagandha), Curcuma longa (Turmeric) and Boswellia serrata (Frankincense) are emphasized for their anti-inflammatory characteristics and possible advantages in managing arthritis. The herbal cubosomes enhance drug absorption, retention, and release kinetics in arthritic conditions. The difficulties in delivering and maintaining herbal substances are also discussed, with a focus on how nanotechnology can help get over these obstacles.

CONCLUSION

Overall, the integration of herbal cubosomes in arthritis therapy presents a promising approach that could result in safer and more efficient treatment alternatives, warranting further research and clinical exploration.

Skin-penetrating peptides (SKPs): Enhancing skin permeation for transdermal delivery of pharmaceuticals and cosmetic compounds

Skin-penetrating peptides (SKPs) are emerging as a promising class of permeation enhancers that can facilitate macromolecule delivery across the skin. Although their pharmaceutical applications are under extensive study, SKPs are crucial for enhancing skin permeability, enabling larger molecules to penetrate the stratum corneum. This review explores the transformative role of SKPs in non-invasive transdermal drug delivery. Drawing from an extensive collection of literature, it provides insights into the current usage and application of SKPs as tools to enhance skin permeability and facilitate the delivery of larger molecules. Additionally, it highlights the opportunities, challenges, and future directions for SKP applications in transdermal drug delivery.

Polymeric Microneedles for Transdermal Delivery of Human Placental Tissue for the Treatment of Osteoarthritis

Biologics targeting matrix-degrading proteases, cartilage repair, and inflammation are emerging as promising approaches for osteoarthritis (OA) treatment. Recent research highlights biologic-human placental tissue (HPT) as a potential OA therapy due to its biocompatibility, abundant protein biofactors, and ability to reduce cartilage degradation by suppressing protease expression. Microneedles (MNs) are receiving growing attention for enhancing transdermal delivery of biologics as an alternative to conventional subcutaneous injections. The lyophilized human placental extract (LHP) loaded polymeric MNs are fabricated using a micromolding technique for transdermal delivery. Ex vivo release studies reveal that MNs exhibit a gradual and consistent release of LHP, indicating a sustained delivery profile. LHP-MNs are nontoxic and anti-inflammatory in nature against human skin cells and interleukin (IL-1β) induced synovial cells. Furthermore, the in vivo study shows that LHP-MNs substantially improve behavioral parameters in OA rat models and lower serum concentrations of tumor necrosis factor- α (TNF-α) and cartilage oligomeric matrix protein (COMP) biomarkers, thereby alleviating knee and ankle joint injuries. Histopathological analysis indicates that LHP-MNs significantly preserve cartilage integrity. The study results suggest that employing polymeric MNs for transdermal delivery of LHP can be a promising treatment approach for OA, with the added benefit of excellent patient compliance.

Transdermal delivery of resveratrol loaded solid lipid nanoparticle as a microneedle patch: a novel approach for the treatment of Parkinson's disease

Parkinson's disease (PD), affecting millions of people worldwide and expected to impact 10 million by 2030, manifests a spectrum of motor and non-motor symptoms linked to the decline of dopaminergic neurons. Current therapies manage PD symptoms but lack efficacy in slowing disease progression, emphasizing the urgency for more effective treatments. Resveratrol (RSV), recognized for its neuroprotective and antioxidative properties, encounters challenges in clinical use for PD due to limited bioavailability. Researchers have investigated lipid-based nanoformulations, specifically solid lipid nanoparticles (SLNs), to enhance RSV stability. Oral drug delivery via SLNs faces obstacles, prompting exploration into transdermal delivery using SLNs integrated with microneedles (MNs) for improved patient compliance. In this study, an RSV-loaded SLNs (RSV -SLNs) incorporated into the MN patch was developed for transdermal RSV delivery to improve its stability and patient compliance. Characterization studies demonstrated favorable physical properties of SLNs with a sustained drug release profile of 78.36 ± 0.74%. The developed MNs exhibited mechanical robustness and skin penetration capabilities. Ex vivo permeation studies displayed substantial drug permeation of 68.39 ± 1.4% through the skin. In an in vivo pharmacokinetic study, the RSV-SLNs delivered through MNs exhibited a significant increase in Cmax, Tmax, and AUC0 - t values, alongside a reduced elimination rate in blood plasma in contrast to the administration of pure RSV via MNs. Moreover, an in vivo study showcased enhanced behavioral functioning and increased brain antioxidant levels in the treated animals. In-vivo skin irritation study revealed no signs of irritation till 24 h which permits long-term MNs application. Histopathological analysis showed notable changes in the brain regions of the rat, specifically the striatum and substantia nigra, after the completion of the treatment. Based on these findings, the development of an RSV-SLN loaded MNs (RSVSNLMP) patch presents a novel approach, with the potential to enhance the drug's efficiency, patient compliance, and therapeutic outcomes for PD, offering a promising avenue for advanced PD therapy.

Dissolving microneedles: A transdermal drug delivery system for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder that impacts around 1% of the global population. Up to 20% of people become disabled within a year, which has a severely negative impact on their health and quality of life. RA has a complicated pathogenic mechanism, which initially affects small joints and progresses to larger ones over time. It can damage the skin, eyes, heart, kidney, and lung. Oral medications, intra-articular injections, and other treatments are being used; nevertheless, they have drawbacks, including low bioavailability, numerous adverse effects, and poor patient compliance. Dissolving microneedles (DMNs) are a safe and painless method for transdermal drug delivery, achieved through their ability to physically penetrate the epidermal barrier. They enable targeted drug delivery, significantly enhancing the bioavailability of medications and improving patient compliance. DMNs are particularly effective in delivering both lipophilic and high molecular weight biomolecules. The superior bioavailability of DMNs is demonstrated by the fact that low-dose DMN administration can achieve up to 25.8 times higher bioavailability compared to oral administration. This paper provides a comprehensive review of recent advancements in the use of DMNs for RA treatment, encompassing various materials (such as hyaluronic acid, chitosan, etc.), fabrication techniques (such as the two-step casting method, photopolymerization), and performance evaluations (including morphology, mechanical properties, skin penetration capability, solubility, and pharmacodynamics). Additionally, a thorough safety assessment has been conducted, revealing that DMNs cause minimal skin irritation and exhibit low cytotoxicity, ensuring their safety for clinical application. DMNs provide a highly effective and promising alternative to oral and injectable drug delivery systems, offering a novel therapeutic approach for RA patients that significantly improves treatment outcomes and enhances their quality of life.

Nano-spanlastics-loaded dissolving microneedle patches for ketotifen fumarate: advanced strategies for allergic conjunctivitis treatment and molecular insights

Allergic conjunctivitis (AC) is the most common inflammatory disease affecting the eye's ocular surface, lid, conjunctiva, and cornea. However, effective ocular drug delivery remains challenging due to physiological barriers such as the corneal barrier. Ketotifen (KF), a widely used antihistamine and mast cell stabilizer, for treating AC and atopic asthma but belongs to the Biopharmaceutical Classification System (BCS II) have poor solubility. This study developed a multiple strategies approach for the first time, utilizing the spanlastics nano-vesicular carriers' system (SP) containing KF using an ethanol injection method. The optimized KF-SP exhibited the smallest particle size, largest zeta-potential and entrapment efficiency ∼232.5 ± 1.9 nm, -28 ± 0.51 and 73 ± 0.02%, respectively were further incorporated into PVA/PVP polymeric dissolving microneedles (MNs) by using a micromolding technique. Scanning electron microscopy (SEM) analysis confirmed well-defined tips and morphology, and in vitro studies showed a controlled 93% cumulative release over 72 h, with a zero-order kinetic release profile, providing stable therapeutic levels. Pharmacodynamic evaluation using the Ovalbumin/Aluminium hydroxide-induced AC model demonstrated significant reductions in IgE, TNF-α, and IL-6 levels by 68.7%, 71.3%, and 67.6%, respectively, while TGF-β and IL-10 levels increased by 70.1% and 62.7% using ELISA (Enzyme-Linked Immunosorbent Assay). Gene expression analysis (IGF-1, Annexin A1, and Bcl2) further supported the therapeutic potential of this system. In this study, we proved the topical application of the multiple strategies approach KF-SP loaded PVA/PVP MNs patch offers a targeted, sustained release treatment for AC, with promising implications for prolonged ocular therapy.

A systematic review of microneedles technology in drug delivery through a bibliometric and patent overview

The transdermal drug delivery (TDD) route has gathered considerable attention for its potential to improve therapeutic efficacy while minimizing systemic side effects. Among transdermal technologies, microneedle (MN) devices have proven to be a promising approach that combines the advantages of traditional needle injections and non-invasive topical applications. This review provides a comprehensive analysis of progress in transdermal drug delivery systems (TDDS) via MN from 2000 to 2023, integrating bibliometric analysis and patent landscape to present a multi-faceted perspective on the evolution of this technology. The study identifies key trends, challenges, and opportunities in the research, implementation, and commercialization of MN tools through a systematic examination of scientific literature and an extensive investigation of global patent databases. The study of bibliometric trends reveals the leading experts, organizations, companies, and countries contributing to this field, collaboration networks, and the thematic evolution of research topics. The patent analysis offers insights into innovative trajectories, key players, and geographical distribution of intellectual property. This review resumes the latest advancements in MN devices and provides a strategic outlook that can guide future research directions, promote partnerships, and inform stakeholders involved in the development of TDDS.

Development and in vitro tuning of empagliflozin-containing dissolvable microneedle patch for enhanced transdermal delivery

This painless method allows drugs to penetrate the outer skin layer, offering several advantages over alternative administration routes, including ease of use and the ability to bypass enterohepatic circulation. Among transdermal drug delivery systems (TDDS), microneedle patches (MNPs) are emerging as an innovative approach for minimally invasive drug delivery, enhancing the skin permeation of substances ranging from macro to micro sizes. This study explores dissolvable microneedle patches (dMNPs) as a novel method to improve the systemic delivery of empagliflozin, an SGLT-2 inhibitor, commonly used to manage type 2 diabetes mellitus (T2DM). However, its oral administration poses challenges due to rapid absorption, variable bioavailability, and a moderate half-life that necessitates frequent dosing. The microneedle patches were manufactured using a mold-based solvent casting technique, utilizing a polymer-drug combination that dissolves upon skin application. The development of the dMNPs involved polyvinylpyrrolidone and polyvinyl alcohol. Characterization of the formulated dMNPs included scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), dissolution testing, tensile strength analysis, percentage elongation measurement, mechanical strength assessment, and skin irritation studies. The optimized dMNP formulation (MP6) exhibited notable characteristics such as sharp, uniform, pyramid-shaped needles, stability at elevated temperatures, crystalline structures of the drug and polymers, controlled weight loss upon heating, effective drug dissolution, optimal tensile strength, penetration depth, moisture content, elongation capability, and a favorable release rate. In vitro release demonstrated the enhanced properties of the dissolvable microneedle patches, with zero-order kinetics identified as the most suitable model for MP6 based on regression coefficient analysis. Overall, the characterization studies, in vitro skin irritation evaluation, confirmed the stability and biocompatibility of the optimized dMNPs, making them suitable for transdermal application.

Microneedle transdermal drug delivery as a candidate for the treatment of gouty arthritis: Material structure, design strategies and prospects

Gouty arthritis (GA) is caused by monosodium urate (MSU) crystals deposition. GA is difficult to cure because of its complex disease mechanism and the tendency to reoccur. GA patients require long-term uric acid-lowering and anti-inflammatory treatments. In the past ten years, as a painless, convenient and well-tolerated new drug transdermal delivery method, microneedles (MNs) administration has been continuously developed, which can realize various drug release modes to deal with various complex diseases. Compared with the traditional administration methods (oral and injection), MNs are more conducive to the long-term independent treatment of GA patients because of their safe, efficient and controllable drug delivery ability. In this review, the pathological mechanism of GA and common therapeutic drugs for GA are summarized. After that, MNs drug delivery mechanisms were summarized: dissolution release mechanism, swelling release mechanism and channel-assisted release mechanism. According to drug delivery patterns of MNs, the mechanisms and applications of rapid-release MNs, long-acting MNs, intelligent-release MNs and multiple-release MNs were reviewed. Additionally, existing problems and future trends of MNs in the treatment of GA were also discussed. STATEMENT OF SIGNIFICANCE: Gout is an arthritis caused by metabolic disease "hyperuricemia". Epidemiological studies show that the number of gouty patients is increasing rapidly worldwide. Due to the complex disease mechanism and recurrent nature of gout, gouty patients require long-term therapy. However, traditional drug delivery modes (oral and injectable) have poor adherence, low drug utilization, and lack of local localized targeting. They may lead to adverse effects such as rashes and gastrointestinal reactions. As a painless, convenient and well-tolerated new drug transdermal delivery method, microneedles have been continuously developed, which can realize various drug release modes to deal with gouty arthritis. In this review, the material structure, design strategy and future outlook of microneedles for treating gouty arthritis will be reviewed.

A Multicomponent Microneedle Patch for the Delivery of Meloxicam for Veterinary Applications

This study evaluates the use of poly(vinyl alcohol), collagen, and chitosan blends for developing a microneedle patch for the delivery of meloxicam (MEL). Results confirm successful MEL encapsulation, structural integrity, and chemical stability even after ethylene oxide sterilization. Mechanical testing indicates the patch has the required properties for effective skin penetration and drug delivery, as demonstrated by load-displacement curves showing successful penetration of pig ear surfaces at 3N of normal load. In vitro imaging confirms the microneedle patch penetrates the pig's ear cadaver skin effectively and uniformly, with histological evaluation revealing the sustained presence and gradual degradation of microneedles within the skin. Additionally, in vitro drug diffusion experiments utilizing ballistic gel suggest that microneedles commence dissolution almost immediately upon insertion into the gel, steadily releasing the drug over 24 h. Furthermore, the microneedle patch demonstrates ideal drug release capabilities, achieving nearly 100% release of meloxicam content from a single patch within 18 h. Finally, in vivo studies using pigs demonstrate the successful dissolution and transdermal drug delivery efficacy of biodegradable microneedle patches delivering meloxicam in a porcine model, with over 70% of microneedles undergoing dissolution after 3 days. While low detectable meloxicam concentrations were observed in the bloodstream, high levels were detected in the ear tissue, confirming the release and diffusion of the drug from microneedles. This work highlights the potential of microneedle patches for controlled drug release in veterinary applications.

Design of poly(vinyl pyrrolidone) and poly(ethylene glycol) microneedle arrays for delivering glycosaminoglycan, chondroitin sulfate, and hyaluronic acid

Osteoarthritis (OA) is a prevalent joint disorder characterized by cartilage and bone degradation. Medical therapies like glucosaminoglycan (GAG), chondroitin sulfate (CS), and hyaluronic acid (HA) aim to preserve joint function and reduce inflammation but may cause side effects when administered orally or via injection. Microneedle arrays (MNAs) offer a localized drug delivery method that reduces side effects. Thus, this study aims to demonstrate the feasibility of delivering GAG, CS, and HA using microneedles in vitro. An optimal needle geometry is crucial for the successful application of MNA. To address this, here we employ a multi-objective optimization framework using the non-dominated sorting genetic algorithm II (NSGA-II) to determine the ideal MNA design, focusing on preventing needle failure. Then, a three-step fabrication approach is followed to fabricate the MNAs. First, the master (male) molds are fabricated from poly(methyl methacrylate) using mechanical micromachining based on optimized needle geometry. Second, a micro-molding with Polydimethylsiloxane (PDMS) is used for the fabrication of production (female) molds. In the last step, the MNAs were fabricated by microcasting the hydrogels using the production molds. Light microscopy (LIMI) confirms the accuracy of the MNAs manufactured, and in vitro skin insertion tests demonstrate failure-free needle insertion. Subsequently, we confirmed the biocompatibility of MNAs by evaluating their impact on the L929 fibroblast cell line, human chondrocytes, and osteoblasts.

Polymeric Microneedle Drug Delivery Systems: Mechanisms of Treatment, Material Properties, and Clinical Applications-A Comprehensive Review

Our comprehensive review plunges into the cutting-edge advancements of polymeric microneedle drug delivery systems, underscoring their transformative potential in the realm of transdermal drug administration. Our scrutiny centers on the substrate materials pivotal for microneedle construction and the core properties that dictate their efficacy. We delve into the distinctive interplay between microneedles and dermal layers, underscoring the mechanisms by which this synergy enhances drug absorption and precision targeting. Moreover, we examine the acupoint-target organ-ganglion nexus, an innovative strategy that steers drug concentration to specific targets, offering a paradigm for precision medicine. A thorough analysis of the clinical applications of polymeric microneedle systems is presented, highlighting their adaptability and impact across a spectrum of therapeutic domains. This review also accentuates the systems' promise to bolster patient compliance, attributed to their minimally invasive and painless mode of drug delivery. We present forward-looking strategies aimed at optimizing stimulation sites to amplify therapeutic benefits. The anticipation is set for the introduction of superior biocompatible materials with advanced mechanical properties, customizing microneedles to cater to specialized clinical demands. In parallel, we deliberate on safety strategies aimed at boosting drug loading capacities and solidifying the efficacy of microneedle-based therapeutics. In summation, this review accentuates the pivotal role of polymeric microneedle technology in contemporary healthcare, charting a course for future investigative endeavors and developmental strides within this burgeoning field.

Biological Fate Tracking of Nitric Oxide-Propelled Microneedle Delivery System Using an Aggregation-Caused Quenching Probe

Nanoparticle-loaded dissolving microneedles (DMNs) have attracted increasing attention due to their ability to provide high drug loading, adjustable drug release behavior, and enhanced therapeutic efficiency. However, such delivery systems still face unsatisfied drug delivery efficiency due to insufficient driving force to promote nanoparticle penetration and the lack of in vivo fate studies to guide formulation design. Herein, an aggregation-caused quenching (ACQ) probe (P4) was encapsulated in l-arginine (l-Arg)-based nanomicelles, which was further formulated into nitric oxide (NO)-propelled nanomicelle-integrated DMNs (P4/l-Arg NMs@DMNs) to investigate their biological fate. The P4 probe could emit intense fluorescence signals in intact nanomicelles, while quenching with the dissociation of nanomicelles, providing a "distinguishable" method for tracking the fate of nanomicelles at a different status. l-Arg was demonstrated to self-generate NO under the tumor microenvironment with excessive reactive oxygen species (ROS), providing a pneumatic force to promote the penetration of nanomicelles in both three-dimensional (3D)-cultured tumor cells and melanoma-bearing mice. Compared with passive microneedles (P4 NMs@DMNs) without a NO propellant, the P4/l-Arg NMs@DMNs possessed a good NO production performance and higher nanoparticle penetration capacity. In conclusion, this study offered an ACQ probe-based biological fate tracking approach to demonstrate the potential of NO-propelled nanoparticle-loaded DMNs in penetration enhancement for topical tumor therapy.

Dissolvable microneedles in the skin: Determination the impact of barrier disruption and dry skin on dissolution

Dissolvable microneedles (DMNs), fabricated from biocompatible materials that dissolve in both water and skin have gained popularity in dermatology. However, limited research exists on their application in compromised skin conditions. This study compares the hyaluronic acid-based DMNs penetration, formation of microchannels, dissolution, and diffusion kinetics in intact, barrier-disrupted (tape stripped), and dry (acetone-treated) porcine ear skin ex vivo. After DMNs application, comprehensive investigations including dermoscopy, stereomicroscope, skin hydration, transepidermal water loss (TEWL), optical coherence tomography (OCT), reflectance confocal laser scanning microscopy (RCLSM), confocal Raman micro-spectroscopy (CRM), two-photon tomography combined with fluorescence lifetime imaging (TPT-FLIM), histology, and scanning electron microscopy (SEM) were conducted. The 400 µm long DMNs successfully penetrated the skin to depths of ≈200 µm for dry skin and ≈200-290 µm for barrier-disrupted skin. Although DMNs fully inserted into all skin conditions, their dissolution rates were high in barrier-disrupted and low in dry skin, as observed through stereomicroscopy and TPT-FLIM. The dissolved polymer exhibited a more significant expansion in barrier-disrupted skin compared to intact skin, with the smallest increase observed in dry skin. Elevated TEWL and reduced skin hydration levels were evident in barrier-disrupted and dry skins compared to intact skin. OCT and RCLSM revealed noticeable skin indentation and pronounced microchannel areas, particularly in barrier-disrupted and dry skin. Additional confirmation of DMN effects on the skin and substance dissolution was obtained through histology, SEM, and CRM techniques. This study highlights the impact of skin condition on DMN effectiveness, emphasizing the importance of considering dissolvability and dissolution rates of needle materials, primarily composed of hyaluronic acid, for optimizing DMN-based drug delivery.

Unravelling the role of microneedles in drug delivery: Principle, perspectives, and practices

In recent year, the research of transdermal drug delivery systems has got substantial attention towards the development of microneedles (MNs). This shift has occurred due to multifaceted advantages of MNs as they can be utilized to deliver the drug deeper to the skin with minimal invasion, offer successful delivery of drugs and biomolecules that are susceptible to degradation in gastrointestinal tract (GIT), act as biosensors, and help in monitoring the level of biomarkers in the body. These can be fabricated into different types based on their applications as well as material for fabrication. Some of their types include solid MNs, hollow MNs, coated MNs, hydrogel forming MNs, and dissolving MNs. These MNs deliver the therapeutics via microchannels deeper into the skin. The coated and hollow MNs have been found successful. However, they suffer from poor drug loading and blocking of pores. In contrast, dissolving MNs offer high drug loading. These MNs have also been utilized to deliver vaccines and biologicals. They have also been used in cosmetics. The current review covers the different types of MNs, materials used in their fabrication, properties of MNs, and various case studies related to their role in delivering therapeutics, monitoring level of biomarkers/hormones in body such as insulin. Various patents and clinical trials related to MNs are also covered. Covered are the major bottlenecks associated with their clinical translation and potential future perspectives.

Formulation and evaluation of dissolving microneedle for transdermal delivery of piperine: the effect of polymers concentration

This research aims to develop the formulation of Dissolving Microneedle Piperine (DMNs PIP) and evaluate the effect of polymer concentration on characterisation and permeation testing results in ex vivo. DMNs PIP were prepared from varying concentrations of piperine (PIP) (10, 15, and 20% w/w) and polymers of polyvinyl alcohol (PVA): Polyvinyl pyrrolidone (30:60 and 60:25), respectively. Then the morphological evaluation of the formula was carried out, followed by mechanical strength testing. Furthermore, the density, LOD, and weight percentage of piperine in the dried microneedle were calculated and the determination of volume, needle weight and piperine weight and analysed. Ex vivo testing, X-Ray Diffraction, FTIR and hemolysis tests were carried out. PIP with PVA and PVP (F1) polymers produced DMN with mechanical strength (8.35 ± 0.11%) and good penetration ability. In vitro tests showed that the F1 polymer mixture gave good penetration (95.02 ± 1.42 μg/cm2), significantly higher than the F2, F3, F4, and F5 polymer mixtures. The DMNs PIP characterisation results through XRD analysis showed a distinctive peak in the 20-30 region, indicating the presence of crystals. The FTIR study showed that the characteristics of piperine found in DMNs PIP indicated that piperine did not undergo interactions with polymers. The results of the ex vivo study through DMNs PIP hemolytic testing showed no hemolysis occurred, with the hemolysis index below the 5% threshold reported in the literature. These findings indicate that DMNs PIP is non-toxic and safe to use as alternative for treating inflammation.

Non-Invasive Delivery of Insulin for Breaching Hindrances against Diabetes

Insulin is recognized as a crucial weapon in managing diabetes. Subcutaneous (s.c.) injections are the traditional approach for insulin administration, which usually have many limitations. Numerous alternative (non-invasive) slants through different routes have been explored by the researchers for making needle-free delivery of insulin for attaining its augmented absorption as well as bioavailability. The current review delineating numerous pros and cons of several novel approaches of non-invasive insulin delivery by overcoming many of their hurdles. Primary information on the topic was gathered by searching scholarly articles from PubMed added with extraction of data from auxiliary manuscripts. Many approaches (discussed in the article) are meant for the delivery of a safe, effective, stable, and patient friendly administration of insulin via buccal, oral, inhalational, transdermal, intranasal, ocular, vaginal and rectal routes. Few of them have proven their clinical efficacy for maintaining the glycemic levels, whereas others are under the investigational pipe line. The developed products are comprising of many advanced micro/nano composite technologies and few of them might be entering into the market in near future, thereby garnishing the hopes of millions of diabetics who are under the network of s.c. insulin injections.

Green Synthetic Strategies and Pharmaceutical Applications of Thiazine and its Derivatives: An Updated Review

Thiazines are a sizable class of organic heterocycles that are notable for their skeletal versatility and relative chemical simplicity, making them among the most flexible sources of biologically active compounds. The term "green synthesis" refers to implementing energy-efficient procedures for the nature-friendly production of materials and chemicals using green solvents, catalysts, and suitable reaction conditions. Considering the importance of green chemistry and the outstanding therapeutic profile of thiazines, the present work was designed to review the recent advances in green chemistry-based synthetic strategies of thiazine and its derivatives. The green synthetic approaches, including microwave-assisted, ultrasound-assisted, and various other synthetic methods for thiazine and its derivatives, were discussed and generalized. In addition, applications of thiazine and its derivatives in pharmaceutical sciences were explained with examples of marketed drugs.The discussed sustainable synthetic methods for thiazines and their derivatives could be useful in developing other medicinally important lead molecules. They could also aid in developing new synthetic schemes and apparatuses that may simplify chemical manufacturing processes and enable novel reactions with minimal by-products while questing for optimal, green solvents. This review can help anyone interested in this fascinating class of heterocycles to make decisions about selecting targets and tasks for future research.

Tiny titans- unravelling the potential of polysaccharides and proteins based dissolving microneedles in drug delivery and theranostics: A comprehensive review

In recent years, microneedles (MNs) have emerged as a promising alternative to traditional drug delivery systems in transdermal drug delivery. The use of MNs has demonstrated significant potential in improving patient acceptance and convenience while avoiding the invasiveness of traditional injections. Dissolving, solid, hollow, coated, and hydrogel microneedles are among the various types studied for drug delivery. Dissolving microneedles (DMNs), in particular, have gained attention for their safety, painlessness, patient convenience, and high delivery efficiency. This comprehensive review primarily focuses on different types of microneedles, fabrication methods, and materials used in fabrication of DMNs such as hyaluronic acid, chitosan, alginate, gelatin, collagen, silk fibroin, albumin, cellulose and starch, to list a few. The review also provides an exhaustive discussion on the applications of DMNs, including the delivery of vaccines, cosmetic agents, contraceptives, hormone and genes, and other therapeutic applications like for treating cancer, skin diseases, and diabetes, among others, are covered in this review. Additionally, this review highlights some of the DMN systems that are presently undergoing clinical trials. Finally, the review discusses current advances and trends in DMNs, as well as future prospective directions for this ground-breaking technology in drug delivery.

Advances in Formulations of Microneedle System for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic joint inflammation, eventually leading to severe disability and premature death. At present, the treatment of RA is mainly to reduce inflammation, swelling, and pain. Commonly used drugs are non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, and disease-modifying anti-rheumatic drugs (DMARDs). These drugs lack specificity and require long-term, high-dose administration, which can cause serious adverse effects. In addition, the oral, intravenous, and intra-articular injections will reduce patient compliance, resulting in high cost and low bioavailability. Due to these limitations, microneedles (MNs) have emerged as a new strategy to efficiently localize the drugs in inflamed joints for the treatment of RA. MNs can overcome the cuticle barrier of the skin without stimulating nerves and blood vessels. Which can increase patient compliance, improve bioavailability, and avoid systemic circulation. This review summarizes and evaluates the application of MNs in RA, especially dissolving MNs (DMNs). We encourage the use of MNs to treat RA, by describing the general properties of MNs, materials, preparation technology, drug release mechanism, and advantages. Furthermore, we discussed the biological safety, development prospects, and future challenges of MNs, hoping to provide a new strategy for the treatment of RA.

Fast dissolving microneedle patch for pronounced systemic delivery of an antihyperlipidemic drug

Fast dissolving microneedles (F-dMN) are quite a novel approach delivering specific drug molecules directly into the bloodstream, bypassing the first-pass effect. The present study reported an F-dMN patch to enhance systemic delivery of simvastatin in a patient-friendly manner. The F-dMN patch was developed using polyvinyl pyrrolidone and polyvinyl alcohol and characterized using light microscopy, SEM, XRD, FTIR, mechanical strength, drug content (%), an ex-vivo penetration study, an ex-vivo drug release study, a skin irritation test, and a pharmacokinetics study. The optimized F-dMN patch exhibited excellent elongation of 35.17%, good tensile strength of 9.68  MPa, an appropriate moisture content of 5.65%, and good penetrability up to 560 µm. Moreover, it showed 93.4% of the drug content within the needles and 81.75% in-vitro release. Histopathological findings and a skin irritation study proved that the F-dMN patch was biocompatible and did not cause any sort of irritation on animal skin. Pharmacokinetic parameters of F-dMN patches were improved (Cmax 6.974 µg/ml, tmax 1 hr and AUC 19. 518 µg.h/ml) as compared to tablet Simva 20 mg solution (Cmax 2.485 µg/ml, tmax 1.4 hr and AUC 11.199 µg.h/ml), thus confirming bioavailability enhancement. Moreover, stability studies confirmed the stability of the developed F-dMN patch, as investigated by axial needle fracture force and drug content.

Efficient fabrication of thermo-stable dissolving microneedle arrays for intradermal delivery of influenza whole inactivated virus vaccine

Dissolving microneedle arrays (dMNAs) can be used to deliver vaccines via the intradermal route. Fabrication of dMNAs using centrifugation is the most common preparation method of dMNAs, but it results in a substantial loss of antigens. In order to solve the issue of antigen waste, we engineered an automatic dispensing system for dMNA preparation. Here, we report on the fabrication of influenza whole inactivated virus (WIV) vaccine-loaded dMNAs (WIV dMNAs) by using the automatic dispensing system. Prior to the dispensing process, polydimethylsiloxane (PDMS) moulds were treated with oxygen plasma to increase surface hydrophilicity. WIV dMNAs were prepared with 1% (w/v) trehalose and pullulan (50 : 50 weight ratio). During the dispensing process, reduced pressure was applied to the PDMS mould via a vacuum chamber to make microneedle cavities airless. After producing dMNAs, WIV was quantified and 1.9 μg of WIV was loaded per dMNA, of which 1.3 μg was in the microneedle tips. Compared to the centrifugation method, this automatic dispensing system resulted in a 95% reduction of antigen waste. A hemagglutination assay confirmed that WIV dMNA maintained the stability of the antigen for at least four weeks of storage, even at room temperature or at 37 °C. The WIV dMNAs displayed 100% penetration efficiency in human skin, and 83% of the microneedle volume was dissolved in the skin within 10 minutes. In a vaccination study, mice immunised with WIV dMNAs showed similar IgG levels to those that received WIV intramuscularly. In conclusion, using the automatic dispensing system for dMNA production strongly reduced antigen waste and yielded dMNAs with excellent physical, mechanical, and immunological properties.

Transdermal drug delivery via microneedles for musculoskeletal systems

As the population is ageing and lifestyle is changing, the prevalence of musculoskeletal (MSK) disorders is gradually increasing with each passing year, posing a serious threat to the health and quality of the public, especially the elderly. However, currently prevalent treatments for MSK disorders, mainly administered orally and by injection, are not targeted to the specific lesion, resulting in low efficacy along with a series of local and systemic adverse effects. Microneedle (MN) patches loaded with micron-sized needle array, combining the advantages of oral administration and local injection, have become a potentially novel strategy for the administration and treatment of MSK diseases. In this review, we briefly introduce the basics of MNs and focus on the main characteristics of the MSK systems and various types of MN-based transdermal drug delivery (TDD) systems. We emphasize the progress and broad applications of MN-based transdermal drug delivery (TDD) for MSK systems, including osteoporosis, nutritional rickets and some other typical types of arthritis and muscular damage, and in closing summarize the future prospects and challenges of MNs application.

Advances in microneedle-based therapy for bone disorders

Bone-related disorders treatment is a serious public health concern, imposing a significant social and economic burden on patients and healthcare systems. Although conventional drug delivery systems have made advances in bone diseases prevention and management, the limited delivery efficiency and convoluted focal environment lead to inadequate drug absorption and lack of specificity to achieve the intended therapeutic impact. Microneedle-based therapy represents an extraordinarily safe and well-tolerable therapeutic approach for treating bone disorders, providing improved efficacy by breaking down the barriers and delivery of therapeutic components to the target sites with programable release profiles in a less invasive manner. Over the past decades, numerous significant achievements in the development of various types of drug-carried microneedles have been made to address the obstacles encountered in the bone-treating procedure, enabling the microneedle-based therapy to take an important step in practical applications. In this light, this review summarizes these remarkable researches in terms of microneedles types and drug delivery strategies, with the goal of demonstrating the benefits of exploiting microneedle-based therapy as a novel strategy for treating bone-related disorders. The remaining challenges and future perspectives are also discussed in the hope of inspiring more efficient and intelligent bone treatment strategies.

Methotrexate delivering microneedle patches for improved therapeutic efficacy in treatment of rheumatoid arthritis

Arthritis is an inflammatory disorder that leads to degeneration and swelling in the joints thereby severely affecting mobility. Till date, a complete cure for this disorder remains elusive. Administration of disease modifying anti-rheumatic drugs has not proved effective owing to poor retention of drugs at the site of inflammation in the joints. In most cases, lack of adherence to the therapeutic regimen further aggravates the condition. Localized administration of the drugs through intra-articular injections is highly invasive and painful. A possible solution to overcome these issues will be to ensure sustained release of the anti-arthritic drug at the site of inflammation through a minimally invasive method. The present work focuses on the development of a microneedle patch for localized and minimally invasive delivery of methotrexate to arthritic joints in guinea pig model. The microneedle patch was found to elicit minimal immune response and ensured sustained release of the drug that was manifested through faster restoration of mobility and a distinct reduction in inflammatory and rheumatoid markers at the joints when compared to untreated and those treated through conventional hypodermic injections. Our results demonstrate the promise of microneedle-based platform for an effective arthritic therapy.

Assessment of formulation variables of poor water soluble diacerein for its improved loading and anti-inflammatory activity

Dissolving microneedles have become a popular method for percutaneous administrationof drugs. However, loading poorly soluble drugs into water-based dissolving microneedles remains a challenge. In view of this, we aimed to improve Diacerein (DCN) solubility formulating dissolving microneedles. DCN microsuspension was created by high-speed homogenization with organic solvents or wet milling with Tween 80 as a stabilizer (LD1). They were analyzed for particle size and saturation solubility. Subsequently, the organic solvent-based microneedles were prepared under vacuum, whereas LD1 was mixed with HPMC (8% w/w) and PVP (30% w/w) matrix to concentrate the drug in acral fraction through centrifugation. DCN microsuspension in DMSO had the highest drug solubility with an average particle size of 6 µm, whereas LD1 had a particle size of 3.28 µm showing improved solubility. TD-3 had the highest drug loading and the least amount of drug migration into the blank baseplate. Within 5 min, these microneedles dissolved completely in an agarose-gel block. LD1 was likewise put in the baseplate to generate TD3-B. Within 24 h, 74.39% of the medication was released from TD3-B, with only a small amount remaining in the baseplate. TLC examination indicated the conversion of DCN to Rhein in the skin, whereas DSC and TGA studies revealed amorphous features. DCN microneedles showed no sign of skin irritancy but showed anti-inflammatory response on carrageenan-induced paw edema model. Microneedles remained stable during accelerated stability testing. Wet milling in the presence of a stabilizer can be an effective approach for enhancing DCN solubility for improved drug loading in dissolving microneedles. Improvement in solubility of Diacerein for subsequent loading in Dissolving Microneedle for percutaneous delivery.

Formulation Development of Fast Dissolving Microneedles Loaded with Cubosomes of Febuxostat: In Vitro and In Vivo Evaluation

Febuxostat is a widely prescribed drug for the treatment of gout, which is a highly prevalent disease worldwide and is a major cause of disability in mankind. Febuxostat suffers from several limitations such as gastrointestinal disturbances and low oral bioavailability. Thus, to improve patient compliance and bioavailability, transdermal drug delivery systems of Febuxostat were developed for obtaining enhanced permeation. Cubosomes of Febuxostat were prepared using a bottom-up approach and loaded into a microneedle using a micromolding technique to achieve better permeation through the skin. Optimization of the process and formulation parameters were achieved using our design of experiments. The optimized cubosomes of Febuxostat were characterized for various parameters such as % entrapment efficiency, vesicle size, Polydispersity index, Transmission electron microscopy, in vitro drug release, Small angle X-ray scattering, etc. After loading it in the microneedle it was characterized for dissolution time, axial fracture force, scanning electron microscopy, in vitro drug release, pore closure kinetics, etc. It was also evaluated for various ex vivo characterizations such as in vitro cell viability, ex vivo permeation, ex vivo fluorescence microscopy and histopathology which indicates its safety and better permeation. In vivo pharmacokinetic studies proved enhanced bioavailability compared with the marketed formulation. Pharmacodynamic study indicated its effectiveness in a disease-induced rat model. The developed formulations were then subjected to the stability study, which proved its stability.

Demonstrating Biological Fate of Nanoparticle-Loaded Dissolving Microneedles with Aggregation-Caused Quenching Probes: Influence of Application Sites

Integrating dissolving microneedles (DMNs) and nanocarriers (NC) holds great potential in transdermal drug delivery because it can simultaneously overcome the stratum corneum barrier and achieve efficient and controlled drug delivery. However, different skin sites with different thicknesses and compositions can affect the transdermal diffusion of NC-loaded DMNs. There are few reports on the biological fate (especially transdermal diffusion) of NC-loaded DMNs, and inaccurate bioimaging information of intact NC limits the accurate understanding of the in vivo fate of NC-loaded DMNs. The aggregation-caused quenching (ACQ) probes P4 emitted intense fluorescence signals in intact NC while quenched after the degradation of NC, had been demonstrated the feasibility of label intact NC. In this study, P4 was loaded in solid lipid nanoparticles (SLNs), and further encapsulated into DMNs, to track the transdermal diffusion of SLNs delivered at different skin sites. The results showed that SLNs had excellent stability after being loaded into DMNs with no significant changes in morphology and fluorescence properties. The in vivo live and ex vivo imaging showed that the transdermal diffusion rate of NC-loaded DMNs was positively correlated with skin thickness, with the order ear > abdomen > back. In conclusion, this study confirmed the site-dependency of transdermal diffusion in NC-loaded DMNs.

PVP-microneedle array for drug delivery: mechanical insight, biodegradation, and recent advances

Microneedle arrays are micron-sized needles usually attached to a supporting base or patch facilitated drug delivery for systemic effects. Polyvinylpyrrolidone (PVP) is a lactam polymer containing an internal amide linkage. Because of its versatility and biocompatibility, it has been widely utilized to treat several skin, bone and eye problems. Due to its specific and unique properties, the researchers realize its utility as a polymer of tremendous potential. PVP-based dissolvable microneedles have widely been utilized as a carrier for delivering DNAs, proteins, vitamins, and several biological macromolecules transdermally. However, it does not get biodegraded into the body. Therefore, the presence of its fragments in the body post-treatment needs proper justification. The adequate justification for the fate of the fragment's end products in the body will allow even better utilization of PVP. This review analyses and illustrates various experimental findings to highlight the most recent advancements and applications of PVP microneedles in drug delivery systems and cosmetology and the potential for PVP microneedles in treating dermal and systemic disorders. This review presents the expected mode of PVP biodegradation in aqueous and soil environments as a waste material, its inertness, biocompatibility, and the importance of PVP as a fabricating material, pharmaceutical uses, and non-toxic profile.

Preparation and in vitro-in vivo evaluation of QbD based acemetacin loaded transdermal patch formulations for rheumatic diseases

This research aimed to develop patches for transdermal delivery of acemetacin, which can be used to treat rheumatic diseasesand to determine their potential use. Patches were successfully created by solvent casting method using hydroxypropyl methylcellulose, propylene glycol, polyethylene glycol 400, tween 80, and dimethyl sulfoxide. Prepared patches were found using the Design of Experiments (DoE) method within the Quality by Design (QbD) approach. F1-ACM with a thickness of 0.1 ± 0.0 cm, a weight of 43.33 ± 6.29 mg, pH of 4.99 ± 0.24, moisture content of 18.33 ± 2.98%, a tensile strength of 9.196 ± 0.441 Mpa, elongation at break of 28.722 ± 0.803% and drug content of 100% was chosen as ideal formulation. 89.7% of ACM from F1-ACM was released in 5 min. F1-ACM significantly (p < 0.05) increased the response latency to the thermal stimulus at 90th (3.071 ± 0.517) and 120th (3.87 ± 0.332) min in the hot plate test. In the tail-flick experiment, F1-ACM significantly (p < 0.05) increased the reaction delay against heat stimuli at 90th (3.016 ± 0.695), 120th (2.884 ± 0.851), and 180th (2.893 ± 0.932) min. F1-ACM patch significantly (p < 0.001) inhibited paw edema formation at 1, 2, 3, 4, and 5 h after induction of inflammation as compared to the control group. Therefore, this formulation can be employed more efficiently for rheumatic disease.

Microneedle-based ocular drug delivery systems - recent advances and challenges

Eye diseases and injuries constitute a significant clinical problem worldwide. Safe and effective delivery of drugs to the eye is challenging mostly due to the presence of ocular barriers and clearance mechanisms. In everyday practice, the traditional eye drops, gels and ointments are most often used. Unfortunately, they are usually not well tolerated by patients due to the need for frequent use as well as the discomfort during application. Therefore, novel drug delivery systems with improved biopharmaceutical properties are a subject of ongoing scientific investigations. Due to the developments in microtechnology, in recent years, there has been a remarkable advance in the development of microneedle-based systems as an alternative, non-invasive form for administering drugs to the eye. This review summarizes the latest achievements in the field of obtaining microneedle ocular patches. In the manuscript, the most important manufacturing technologies, microneedle classification, and the research studies related to ophthalmic application of microneedles are presented. Finally, the most important advantages and drawbacks, as well as potential challenges related to the unique anatomy and physiology of the eye are summarized and discussed.

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.

Phellodendri Chinensis Cortex-Based Nanoparticles Integrated in Dissolvable Microneedles for Ameliorating Psoriasis-Like Inflammation

Psoriasis is a common and highly relapsing skin disease, for which topical treatments are used by approximately 88% of people with psoriasis as their primary therapy. However, in practice, the low convenience and side effects such as skin irritation of current topical treatments limit the application of the therapy. To address these issues, we calcined Phellodendri Chinensis Cortex (PCC) to prepare Phellodendri Chinensis Cortex Nanoparticles (PCC-NPs) which were packed into dissolvable microneedles (MNs) for the treatment of psoriasis. In this study, we revealed that the trace amounts of PCCNPs delivered by MNs could exert therapeutic effects therapeutic effects in the affected skin comparable to those of standard drugs, accompanied with the suppressed psoriasis-like inflammation without significant hepatic or renal toxicity or allergic reactions. These results indicate that dissolvable PCC-NPs MNs may serve as an innovative topical therapy for the inhibition of psoriatic inflammation.

Promising Strategies for Transdermal Delivery of Arthritis Drugs: Microneedle Systems

Arthritis is a general term for various types of inflammatory joint diseases. The most common clinical conditions are mainly represented by rheumatoid arthritis and osteoarthritis, which affect more than 4% of people worldwide and seriously limit their mobility. Arthritis medication generally requires long-term application, while conventional administrations by oral delivery or injections may cause gastrointestinal side effects and are inconvenient for patients during long-term application. Emerging microneedle (MN) technology in recent years has created new avenues of transdermal delivery for arthritis drugs due to its advantages of painless skin perforation and efficient local delivery. This review summarizes various types of arthritis and current therapeutic agents. The current development of MNs in the delivery of arthritis drugs is highlighted, demonstrating their capabilities in achieving different drug release profiles through different self-enhancement methods or the incorporation of nanocarriers. Furthermore, the challenges of translating MNs from laboratory studies to the clinical practice and the marketplace are discussed. This promising technology provides a new approach to the current drug delivery paradigm in treating arthritis in transdermal delivery.

Biodegradable microneedle patch for delivery of meloxicam for managing pain in cattle

Microneedle patches are a promising source for transdermal diffusion of macromolecules and are designed to painlessly penetrate the skin. In this study, a biodegradable chitosan microneedle patch to deliver meloxicam for managing pain in cattle was tested. The potential of reuse of the polymeric solution to fabricate the patches, optimization of fabrication, morphological analysis of the microneedle patch and analysis of preservation of the chemical composition after sterilization were evaluated. In-vitro analysis consisted of studying in-vitro penetration mechanical properties, compression testing analysis of microneedle patch, and in-vitro drug release analysis. In-vivo studies were performed to analyze the dissolution capability of the microneedle patch. Results regarding the physical characteristics, chemical composition, and mechanical properties confirmed that rheological properties of the chitosan solution, present significant differences over time, demonstrating that reusing the solution on the fourth day results in failure patches. Morphological characteristics and chemical composition studies revealed that the process of sterilization (ethylene oxide gas) needed for implanting the patches into the skin did not affect the properties of microneedle patches. In-vitro studies showed that approximately 33.02 ± 3.88% of the meloxicam was released over 7 days. A full penetration of the microneedles into the skin can be obtained by applying approximately 3.2 N. In-vivo studies demonstrated that microneedle patches were capable of swelling and dissolving, exhibiting a dissolution percentage of more than 50% of the original height of microneedle after 7 days. No abnormal tissue, swelling, or inflammation was observed in the implanted area. The results of this work show that chitosan biodegradable microneedle patches may be useful to deliver meloxicam to improve pain management of cattle with positive effects for commercial manufacturing.

Polymer nanotherapeutics: A versatile platform for effective rheumatoid arthritis therapy

Rheumatoid arthritis is an aggressive and severely debilitating disorder that is characterized by joint pain and cartilage damage. It restricts mobility in patients, leaving them unable to carry out simple tasks. RA presents itself with severe lasting pain, swelling and stiffness in the joints and may cause permanent disability in patients. Treatment regimens currently employed for rheumatoid arthritis revolve around keeping clinical symptoms like joint pain, inflammation, swelling and stiffness at bay. The current therapeutic interventions in rheumatoid arthritis involve the use of non-steroidal anti-inflammatory drugs, glucocorticoids, disease-modifying anti-rheumatic drugs and newer biological drugs that are engineered for inhibiting the expression of pro-inflammatory mediators. These conventional drugs are plagued with severe adverse effects because of their higher systemic distribution, lack of specificity and higher doses. Oral, intra-articular, and intravenous routes are routinely used for drug delivery which is associated with decreased patient compliance, high cost, poor bioavailability and rapid systemic clearance. All these drawbacks have enticed researchers to create novel strategies for drug delivery, the main approach being nanocarrier-based systems. In this article, we aim to consolidate the remarkable contributions of polymeric carrier systems including microneedle technology and smart trigger-responsive polymeric carriers in the management of rheumatoid arthritis along with its detailed pathophysiology. This review also briefly describes the safety and regulatory aspects of polymer therapeutics.

Feasibility of Enhancing Skin Permeability of Acyclovir through Sterile Topical Lyophilized Wafer on Self-Dissolving Microneedle-Treated Skin

Acyclovir is an antiviral drug that is frequently prescribed for the herpes virus. However, the drug requires frequent dosing due to limited bioavailability (10–26.7%). The rationale of the present study was to develop a self-dissolving microneedle system for local and systemic delivery of acyclovir using a topical lyophilized wafer on microneedle-treated skin to provide the drug at the site of infection. The microneedles prepared with hydroxypropyl methylcellulose (HPMC) (8% w/w) or HPMC (8% w/w)-polyvinyl pyrrolidone (PVP) (30% w/w) penetrated excised rat skin, showing sufficient mechanical strength and rapid polymer dissolution. The topical wafer was prepared with acyclovir (40% w/w; equivalent to 200 mg of drug), gelatin (10% w/w), mannitol (5% w/w), and sodium chloride (5% w/w). The uniform distribution of acyclovir within the wafer in an amorphous form was confirmed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). No polymer–drug interaction was evident in the lyophilized wafer as per Fourier transform infrared spectroscopy (FTIR) analysis. The wafer showed a sufficiently porous structure for rapid hydration as per scanning electron microscopy (SEM) analysis. During ex-vivo analysis, the skin was pre-treated with a self-dissolving microneedle array for 5 minutes, and the wafer was placed on this microporated-skin. Topical wafer provided ∼7–11 times higher skin concentration than the ID₉₉ reported with a lower lag-time. Based on in-vivo testing, ∼2.58 µg/ml of Cmax was achieved in rabbit plasma during 24 hours’ study. Our findings suggest that the self-dissolving microneedle-assisted topical wafer, proposed for the first time, would be efficacious against the infection residing in the skin layer and for systemic therapy.

Potential of Microneedle Systems for COVID-19 Vaccination: Current Trends and Challenges

To prevent the coronavirus disease 2019 (COVID-19) pandemic and aid restoration to prepandemic normality, global mass vaccination is urgently needed. Inducing herd immunity through mass vaccination has proven to be a highly effective strategy for preventing the spread of many infectious diseases, which protects the most vulnerable population groups that are unable to develop immunity, such as people with immunodeficiencies or weakened immune systems due to underlying medical or debilitating conditions. In achieving global outreach, the maintenance of the vaccine potency, transportation, and needle waste generation become major issues. Moreover, needle phobia and vaccine hesitancy act as hurdles to successful mass vaccination. The use of dissolvable microneedles for COVID-19 vaccination could act as a major paradigm shift in attaining the desired goal to vaccinate billions in the shortest time possible. In addressing these points, we discuss the potential of the use of dissolvable microneedles for COVID-19 vaccination based on the current literature.

Recent advances on transdermal delivery systems for the treatment of arthritic injuries: From classical treatment to nanomedicines

Arthritic injuries happen frequently during a lifetime due to accidents, sports, aging, diseases, etc. Such injuries can be cartilage/bone injuries, tendon injuries, ligament injuries, inflammation, pain, and/or synovitis. Oral and injective administration of therapeutics are typically used but cause many side effects. Transdermal administration is an alternative route for safe and efficient delivery. Transdermal formulations of non-steroidal anti-inflammatory drugs have been available on market for years and show promising efficacy in pain relieving, inflammation alleviation, infection control, and so on. Innovative transdermal patches, gels/films, and microneedles have also been widely explored as formulations to deliver therapeutics to combat arthritic injuries. However, transdermal formulations that halt disease progression and promote damage repair are translated slowly from lab bench to clinical applications. One major reason is that the skin barrier and synovial capsule barrier limit the efficacy of transdermal delivery. Recently, many nanocarriers, such as nanoparticles, nanolipids, nanoemulsions, nanocrystals, exosomes, etc., have been incorporated into transdermal formulations to advance drug delivery. The combined transdermal formulations show promising safety and efficacy. Therefore, this review will focus on stating the current development of nanomedicine-based transdermal formulations for the treatment of arthritic injuries. The advances, limitations, and future perspectives in this field will also be provided to inspire future studies and accelerate clinical translational studies. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Biology-Inspired Nanomaterials > Lipid-Based Structures.

Emerging trends in microneedle-based drug delivery strategies for the treatment of rheumatoid arthritis

INTRODUCTION

The current drug therapies for treating Rheumatoid Arthritis (RA) include NSAIDs, DMARDs, or biological products designed to mitigate the symptoms of the disease. These therapies with conventional delivery systems possess limitations such as lack of selectivity and adverse effects in the extra-articular tissues. Microneedles-based transdermal drug delivery gained huge attention that can overcome the limitations associated with conventional preparations.

AREAS COVERED

This review aims to provide detailed information on types of Microneedles (MNs) and their usage in drug delivery for the management of Rheumatoid Arthritis. In addition, it also provides evidence for the effective use of MNs in RA treatment. Various types of MNs, their regulatory status, clinical trials and patents are also compiled in this review.

EXPERT OPINION

Microneedles are small patch-like structures consisting of needles in micron range arranged in array-like structure, used to manage drugs designed to be given via transdermal route. Microneedles provide painless delivery, fast onset of action, bypass the first-pass metabolism and be easily self-administered. In the case of RA treatment, which requires a long-term application of drugs, MNs is a new and emerging way to ease the symptoms of RA.

Recent Advances of Microneedles and Their Application in Disease Treatment

For decades, scientists have been doing a lot of research and exploration to find effective long-term analgesic and/or disease-modifying treatments. Microneedles (MNs) are a simple, effective, and painless transdermal drug delivery technology that has emerged in recent years, and exhibits great promise for realizing intelligent drug delivery. With the development of materials science and fabrication technology, the MN transdermal drug delivery technology has been applied and popularized in more and more fields, including chronic illnesses such as arthritis or diabetes, cancer, dermatocosmetology, family planning, and epidemic disease prevention, and has made fruitful achievements. This paper mainly reviews the latest research status of MNs and their fabrication methodology, and summarizes the application of MNs in the treatment of various diseases, as well as the potential to use nanotechnology to develop more intelligent MNs-based drug delivery systems.

Recent progress in polymeric non-invasive insulin delivery

The design of carriers for insulin delivery has recently attracted major research attentions in the biomedical field. In general, the release of drug from polymers is driven via a variety of polymers. Several mechanisms such as matrix release, leaching of drug, swelling, and diffusion are usually adopted for the release of drug through polymers. Insulin is one of the most predominant therapeutic drugs for the treatment of both diabetes mellitus; type-I (insulin-dependent) and type II (insulin-independent). Currently, insulin is administered subcutaneously, which makes the patient feel discomfort, pain, hyperinsulinemia, allergic responses, lipodystrophy surrounding the injection area, and occurrence of miscarried glycemic control. Therefore, significant research interest has been focused on designing and developing new insulin delivery technologies to control blood glucose levels and time, which can enhance the patient compliance simultaneously through alternative routes as non-invasive insulin delivery. The aim of this review is to emphasize various non-invasive insulin delivery mechanisms including oral, transdermal, rectal, vaginal, ocular, and nasal. In addition, this review highlights different smart stimuli-responsive insulin delivery systems including glucose, pH, enzymes, near-infrared, ultrasound, magnetic and electric fields, and the application of various polymers as insulin carriers. Finally, the advantages, limitations, and the effect of each non-invasive route on insulin delivery are discussed in detail.

Transdermal release of methotrexate by cationic starch/poly(vinyl alcohol)-based films as an approach for rheumatoid arthritis treatment

Methotrexate (MTX) is a common drug used for rheumatoid arthritis (RA) treatment; however, a series of adverse effects associated with its oral or subcutaneous administration is reported. Transdermal delivery of MTX is an alternative to abate these issues, and the use of drug delivery systems (DDS) based on polymeric films presents an impressive potential for this finality. Based on this, in this study, we report the preparation of films made by cationic starch (CSt), poly(vinyl alcohol) (PVA), and chondroitin sulfate (ChS) to incorporate and release MTX, as well as the in vivo evaluation in model of rheumatoid arthritis in mice. CSt/PVA and CSt/PVA/ChS-based films (with and without MTX) were prepared using a simple protocol under mild conditions. The films loaded with 5 w/w-% of MTX exhibited appreciable drug loading efficiency and distribution. The MTX permeation through the layers of porcine skin demonstrated that most of the drug permeated was detected in the medium, suggesting that the formulation can provide a systemic absorption of the MTX. In vivo studies performed in an arthritis-induced model in mice demonstrated that the MTX-loaded films were able to treat and attenuate the symptoms and the biochemical alterations related to RA (inflammatory process, oxidative stress, and nociceptive behaviors). Besides, the pharmacological activity of MTX transdermally delivery by the CSt/PVA and CSt/PVA/ChS films was comparable to the MTX orally administered. Based on these results, it can be inferred that both films are prominent materials for incorporation and transdermal delivery of MTX in a practical and non-invasive manner.

Programmable Polymeric Microneedles for Combined Chemotherapy and Antioxidative Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease. Antioxidative treatment combined with chemotherapy holds great promise for RA treatment, and the ability to efficiently deliver drugs and antioxidants to the RA synovial joint is highly desired. Herein, we developed a programmable polymeric microneedle (MN) platform for transdermal delivery of methotrexate (MTX) and reactive oxygen species (ROS) scavengers for RA treatment. The biodegradable MNs made of polyvinylpyrrolidone (PVP) were incorporated with polydopamine/manganese dioxide (termed PDA@MnO₂) and MTX. After insertion into skin tissue, the MNs degraded, thus enabling release of loaded MTX and PDA@MnO₂. The PDA@MnO₂ could be utilized as an MRI contrast agent in the RA synovial microenvironment. It also acted as a robust antioxidant to remove ROS and decrease RA inflammation, which when combined with the MTX-mediated chemotherapy led to an ideal outcome for RA treatments in a murine model. This work not only represents a valuable MN-assisted RA therapeutic agent transdermal delivery approach but also opens a new avenue for chemotherapy and antioxidative synergistic treatment of RA.

Fabrication and Evaluation of Transdermal Delivery of Carbamazepine Dissolving Microneedles

This project aims to prepare hydrogel microneedle patches (MNs) as a painless method to deliver carbamazepine transdermally. This can be used as a sustained release system that offers the advantages of lower gastrointestinal side effects and avoids the first-pass metabolism of the drug. MNs were composed of two medicated layers, a microneedle layer and a base layer. MNs were fabricated using polyvinyl alcohol with or without polyvinylpyrrolidone Kollidon 30 as a matrix polymer and in the presence of selected solubilizing agent (polyethylene glycol 400, Tween 80, or α-tocopherol polyethylene glycol). Freezing-thawing cycle was evaluated as one of the processing parameters that may affect the drug release. The MNs were evaluated for their weight variation, base thickness, and content uniformity. The physicochemical compatibility between carbamazepine and the polymers was estimated by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and X-ray powder diffraction. Evaluation for the in vitro release studies and ex vivo permeation studies was performed. The prepared MNs were flexible, clear, and uniform in weight, base thickness, and drug content. Physicochemical characterizations showed that carbamazepine was amorphous in most of the MNs. In vitro release and ex vivo permeation studies of carbamazepine were significantly higher for MNs containing a combination of 1:1 w/w of PEG 400 and Tween 80 as solubilizing agents where the release was extended over 96 h, with the release of 85.2% and 59.6% permeation percentage compared to other MNs. A significant effect of the freezing-thawing cycle on the release profile of the drug was observed. The hydrogel MNs are shown to be stable under the studied storage conditions.