Dissolving microneedle based transdermal delivery of therapeutic peptide analogues

Application of hydrogel microneedles in the oral cavity

Microneedles are a transdermal drug delivery system in which the needle punctures the epithelium to deliver the drug directly to deep tissues, thus avoiding the influence of the first-pass effect of the gastrointestinal tract and minimizing the likelihood of pain induction. Hydrogel microneedles are microneedles prepared from hydrogels that have good biocompatibility, controllable mechanical properties, and controllable drug release and can be modified to achieve environmental control of drug release in vivo. The large epithelial tissue in the oral cavity is an ideal site for drug delivery via microneedles. Hydrogel microneedles can overcome mucosal hindrances to delivering drugs to deep tissues; this prevents humidity and a highly dynamic environment in the oral cavity from influencing the efficacy of the drugs and enables them to obtain better therapeutic effects. This article analyzes the materials and advantages of common hydrogel microneedles and reviews the application of hydrogel microneedles in the oral cavity.

Advancements in transdermal drug delivery: A comprehensive review of physical penetration enhancement techniques

Transdermal drug administration has grown in popularity in the pharmaceutical research community due to its potential to improve drug bioavailability, compliance among patients, and therapeutic effectiveness. To overcome the substantial barrier posed by the stratum corneum (SC) and promote drug absorption within the skin, various physical penetration augmentation approaches have been devised. This review article delves into popular physical penetration augmentation techniques, which include sonophoresis, iontophoresis, magnetophoresis, thermophoresis, needle-free injection, and microneedles (MNs) Sonophoresis is a technique that uses low-frequency ultrasonic waves to break the skin's barrier characteristics, therefore improving drug transport and distribution. In contrast, iontophoresis uses an applied electric current to push charged molecules of drugs inside the skin, effectively enhancing medication absorption. Magnetophoresis uses magnetic fields to drive drug carriers into the dermis, a technology that has shown promise in aiding targeted medication delivery. Thermophoresis is the regulated heating of the skin in order to improve drug absorption, particularly with thermally sensitive drug carriers. Needle-free injection technologies, such as jet injectors (JIs) and microprojection arrays, offer another option by producing temporary small pore sizes in the skin, facilitating painless and effective drug delivery. MNs are a painless, minimally invasive method, easy to self-administration, as well as high drug bioavailability. This study focuses on the underlying processes, current breakthroughs, and limitations connected with all of these approaches, with an emphasis on their applicability in diverse therapeutic areas. Finally, a thorough knowledge of these physical enhancement approaches and their incorporation into pharmaceutical research has the potential to revolutionize drug delivery, providing more efficient and secure treatment choices for a wide range of health-related diseases.

Microarray needles comprised of arginine-modified chitosan/PVA hydrogel for enhanced antibacterial and wound healing potential of curcumin

Wound healing is a multifaceted and complex process that includes inflammation, hemostasis, remodeling, and granulation. Failures in any link may cause the healing process to be delayed. As a result, wound healing has always been a main research focus across the entire medical field, posing significant challenges and financial burdens. Hence, the current investigation focused on the design and development of arginine-modified chitosan/PVA hydrogel-based microneedles (MNs) as a curcumin (CUR) delivery system for improved wound healing and antibacterial activity. The substrate possesses exceptional swelling capabilities that allow tissue fluid from the wound to be absorbed, speeding up wound closure. The antibacterial activity of MNs was investigated against S. aureus and E. coli. The results revealed that the developed CUR-loaded MNs had increased antioxidant activity and sustained drug release behavior. Furthermore, after being loaded in the developed MNs, it revealed improved antibacterial activity of CUR. Wound healing potential was assessed by histopathological analysis and wound closure%. The observed results suggest that the CUR-loaded MNs greatly improved wound healing potential via tissue regeneration and collagen deposition, demonstrating the potential of developed MNs patches to be used as an effective carrier for wound healing in healthcare settings.

Development of dissolving microneedles for intradermal delivery of the long-acting antiretroviral drug bictegravir

Oral administration and intramuscular (IM) injection are commonly recommended options for human immunodeficiency virus (HIV) treatment. However, poor patient compliance due to daily oral dosing, pain at injection sites and the demand for trained healthcare staff for injections limit the success of these administration routes, especially in low-resource settings. To overcome these limitations, for the first time, we propose novel bilayer dissolving microneedles (MNs) for the intradermal delivery of long-acting nanosuspensions of the antiretroviral (ARV) drug bictegravir (BIC) for potential HIV treatment and prevention. The BIC nanosuspensions were prepared using a wet media milling technique on a laboratory scale with a particle size of 358.99 ± 18.53 nm. The drug loading of nanosuspension-loaded MNs and BIC powder-loaded MNs were 1.87 mg/0.5 cm² and 2.16 mg/0.5 cm², respectively. Both dissolving MNs exhibited favorable mechanical and insertion ability in the human skin simulant Parafilm® M and excised neonatal porcine skin. Importantly, the pharmacokinetic profiles of Sprague Dawley rats demonstrated that dissolving MNs were able to intradermally deliver 31% of drug loading from nanosuspension-loaded MNs in the form of drug depots. After a single application, both coarse BIC and BIC nanosuspensions achieved sustained release, maintaining plasma concentrations above human therapeutic levels (162 ng/mL) in rats for 4 weeks. These minimally invasive and potentially self-administered MNs could improve patient compliance, providing a promising platform for the delivery of nanoformulated ARVs and resulting in prolonged drug release, particularly for patients in low-resource settings.

Sustained Release Microneedles: Materials and Applications in Facial Rejuvenation

Wrinkled and loose skin resulting from collagen degradation along with fibers decreasing reflects the youth diminishing. Microneedles (MNs) have opened up new avenues for the development of painless and noninvasive transdermal drug delivery systems for facial rejuvenation. Encapsulated drugs or molecules are transmitted to targeted tissues via percutaneous microchannels, which eliminate potential gastric stimulation or first-pass metabolic effects, as well as boost patient compliance. Although MNs are considered effective and feasible therapeutic alternatives to metals, silicon, and polymers, traditional procedures with reduction processes continue to encounter methodological limitations. In recent years, promising additive manufacturing processes such as three-dimensional printing and two-photon polymerization manufacturing have been developed with the aim of overcoming the limitations by traditional processes to facilitate an efficient and economic production mode. This review summarizes the design, material selection, and manufacturing method for recently advanced MN systems. Furthermore, we also highlight specific polymeric or natural microneedle products, like hyaluronan, plant derivates, and vitamins, for esthetic applications in this review. Impact Statement In this review, the materials and manufactural routes of microneedles (MNs) are detailed. Moreover, similar to the diagnostic or therapeutic MNs, the feature of dispensation with training and ready-to-use is perfect for beautification and anti-aging, which necessitate repeated and long-term usage. Furthermore, the specific polymeric or natural products for esthetic applications of MNs are highlighted in this review.

3D Printed Hollow Microneedles for Treating Skin Wrinkles Using Different Anti-Wrinkle Agents: A Possible Futuristic Approach

Skin wrinkles are an inevitable phenomenon that is brought about by aging due to the degradation of scleroprotein fibers and significant collagen reduction, which is the fundamental basis of anti-wrinkle technology in use today. Conventional treatments such as lasering and Botulinum toxin have some drawbacks including allergic skin reactions, cumbersome treatment procedures, and inefficient penetration of the anti-wrinkle products into the skin due to the high resistance of stratum corneum. Bearing this in mind, the cosmetic industry has exploited the patient-compliant technology of microneedles (MNs) to treat skin wrinkles, developing several products based on solid and dissolvable MNs incorporated with antiwrinkle formulations. However, drug administration via these MNs is limited by the high molecular weight of the drugs. Hollow MNs (HMNs) can deliver a wider array of active agents, but that is a relatively unexplored area in the context of antiwrinkle technology. To address this gap, we discuss the possibility of bioinspired 3D printed HMNs in treating skin wrinkles in this paper. We compare the previous and current anti-wrinkling treatment options, as well as the techniques and challenges involved with its manufacture and commercialization.

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.

Latest on biomaterial-based therapies for topical treatment of psoriasis

Psoriasis is an autoimmune inflammatory disease which is fundamentally different from dermatitis. Its treatments include topical medications and systemic drugs depending on different stages of the disease. However, these commonly used therapies are falling far short of clinical needs due to various drawbacks. More precise therapeutic strategies with minimized side effects and improved compliance are highly demanded. Recently, the rapid development of biomaterial-based therapies has made it possible and promising to attain topical psoriasis treatment. In this review, we briefly describe the significance and challenges of the topical treatment of psoriasis and emphatically overview the latest progress in novel biomaterial-based topical therapies for psoriasis including microneedles, nanoparticles, nanofibers, and hydrogels. Current clinical trials related to each biomaterial are also summarized and discussed.

A Dual-Delivery Platform for Vaccination using Antigen-loaded Nanoparticles in Dissolving Microneedles

Effective vaccines delivered via painless methods would revolutionize the way people approach vaccinations. This study focused on the development of fast-dissolving microneedles (MNs) to deliver antigen-loaded sustained release polymeric nanoparticles (NPs), achieving a dual-delivery platform for vaccination through the skin. The platform utilizes dissolving MNs (dMNs), which penetrate to the epidermal layer of the skin and rapidly dissolve, releasing the antigen-loaded NPs. In this study, seven dissolving microneedle formulations were tested based on screening of various biocompatible and biodegradable polymers and sugars. The lead dMN formulation was selected based on optimal mechanical strength and dissolution of the needles and was loaded with poly(lactic-co-glycolic) acid (PLGA) NPs encapsulating a model influenza matrix 2 (M2) protein antigen. Antigen-loading efficiency in the needles was determined by centrifugation of the lead formulation containing various concentrations of antigen nanoparticles. Next, the reproducibility and translatability of ex vivo mechanical strength and dissolvability of the lead M2 PLGA NP-loaded dMN formulation was assessed by formulating and testing two different microneedle arrays on murine and porcine skin. Finally, the lead microneedle array was loaded with fluorescent dye NPs and evaluated for pore formation and closure in vivo in a murine model. This proof-of-concept study yielded an easy-to-formulate, well-characterized, translatable antigen NP-loaded dMN platform for transdermal vaccine administration.

Dissolving microneedle rollers for rapid transdermal drug delivery

Dissolving microneedle patch (DMNP) is a minimally invasive and painless self-administration device. However, due to skin deformation, it is difficult to apply it on the large areas of skin or curved skin as the patch size increased for DMNP. Here, we propose a polyvinyl alcohol (PVA)-based dissolving microneedle roller (DMNR) device that can be used for delivering drugs rapidly on the large surface areas or curved skin and does not need to be attached on the skin all the time during drug delivery. The hypoglycemic effect of insulin-loaded DMNRs for transdermal delivery of insulin was studied on the type 1 diabetic rat models. It was found that the insulin-loaded DMNR has an immediate and effective hypoglycemic effect that the blood glucose level reduced below to 50% of original blood glucose at 1 h after DMNRs administrated.

Advances in microneedle-based transdermal delivery for drugs and peptides

Transdermal drug delivery is a viable and clinically proven route of administration. This route specifically requires overcoming the mechanical barrier provided by the Stratum Corneum of epidermis and vascular and nervous networks within the dermis. First-generation Transdermal patches and second-generation iontophoretic patches have been translated into commercial clinical products successfully. The current review reports different studies that aim to enhance the transdermal delivery of biopharmaceutical using microneedles and their effect on drug delivery. Microneedles (MN) are the micron-scale hybrid between transdermal patches and hypodermic syringes. Microneedles are tested and proven to show better delivery of the drugs, overcoming the drawbacks of hypodermic syringes. Multiple microneedles designs have been fabricated i.e. solid, coated, hollow, and polymer microneedles. Hollow microneedles are shorter in length but similar to hypodermic needles and have pore for infusion of liquid formulation of the drug. Solid microneedles a patch is applied after creating a hole in the skin; Drugs are coated on the surface of Coated microneedles; Polymer microneedles can be of different types like dissolving, non-dissolving or hydrogel-forming made up of polymers. Various advantages and limitations associated with the use of these techniques are discussed. Delivery of peptide and protein molecules with microneedles represents a significant opportunity for a better clinical outcome and hence value creation compared to standard injectable routes of administration. The advancement in various formulation and microfabrication techniques are currently being focused to aid the delivery of protein drugs via microneedles. The most recent advances and limitations in Microneedles -mediated protein and peptide delivery were discussed.

Panorama of dissolving microneedles for transdermal drug delivery

Recently, microfabrication technology has been developed to increase the permeability of drugs for transdermal delivery. Microneedles are ultra-small needles usually in the micron size range (different dimensions in micron), generate pores, and allow for delivery of local medication in the systemic circulation via skin. The microneedles have been available in dissolving, solid, coated, hollow, and hydrogel-based microneedles. Dissolving microneedles have been fabricated using micro-molding, photo-polymerization, drawing lithography and droplet blowing techniques. Dissolving microneedles could be a valuable option for the delivery of low molecular weight drugs, peptides, enzymes, vaccines and bio-therapeutics. It consists of water-soluble materials including maltose, polyvinyl pyrrolidone, chondroitin sulfate, dextran, hyaluronic acid, and albumin. The microneedles have almost dissolved after patch removal, leaving only blunt stubs behind, which are easily removable. In this review, we summarize the major building blocks, classification, fabrication techniques, characterization, diffusion models and application of microneedles in diverse area. We also reviewed the regulatory aspects, computational studies, patents, clinical data, and market trends of microneedles.

Translation of Polymeric Microneedles for Treatment of Human Diseases: Recent Trends, Progress, and Challenges

The ongoing search for biodegradable and biocompatible microneedles (MNs) that are strong enough to penetrate skin barriers, easy to prepare, and can be translated for clinical use continues. As such, this review paper is focused upon discussing the key points (e.g., choice polymeric MNs) for the translation of MNs from laboratory to clinical practice. The review reveals that polymers are most appropriately used for dissolvable and swellable MNs due to their wide range of tunable properties and that natural polymers are an ideal material choice as they structurally mimic native cellular environments. It has also been concluded that natural and synthetic polymer combinations are useful as polymers usually lack mechanical strength, stability, or other desired properties for the fabrication and insertion of MNs. This review evaluates fabrication methods and materials choice, disease and health conditions, clinical challenges, and the future of MNs in public healthcare services, focusing on literature from the last decade.

A quantitative UHPLC-MS/MS method for the growth hormone-releasing peptide-6 determination in complex biological matrices and transdermal formulations

Growth hormone-releasing peptide-6 (GHRP-6) is part of a group of small synthetic peptides with potent GH-releasing activity that have gained attention in the last two decades by virtue of their cyto- and cardioprotective effects. Despite numerous preclinical studies highlighting the potential cardiovascular benefits of GHRP-6, confirmation of clinical efficacy is still awaited. Recent advances in transdermal drug delivery systems have been made to address challenges related to the poor skin permeation rate of peptides by using pain-free microneedle (MN) devices. Accordingly, highly sensitive and validated analytical methods are required for the potential clinical translation of MN-based peptides. The ultra-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) methods developed in this study aimed to quantify GHRP-6 in biological matrices (plasma, skin) and dissolving polymeric MNs. UHPLC/MS-MS method detection limits of 0.1, 1.1, 0.9 and 1.5 ng/mL were achieved in neat solution, plasma, MN polymer solution, and skin matrices, respectively. Method validation also involved assessment of precision, accuracy, limits of quantification, linearity of matched calibration curves (R² > 0.990), extraction recovery, matrix effect, stability studies, selectivity, and carry-over effect. Additionally, quality control samples were analyzed at three concentration levels to determine recovery (85-109%) and accuracy/bias (3.2-14.7%). Intra- and inter-day precision were within the range of acceptance (RSDs of 3.0-13.9% and 0.4-14.5%, respectively). The validity and applicability of such methods were successfully demonstrated for transdermal GHRP-6 delivery using GHRP-6-loaded MN patches applied to pig skin.

Design and Evaluation of Dissolving Microneedles for Enhanced Dermal Delivery of Propranolol Hydrochloride

Oral propranolol hydrochloride has been the first-line treatment for infantile hemangioma (IH), whereas systemic exposure to propranolol has the potential of causing serious adverse reactions. Dermal delivery of propranolol is preferable due to high local drug concentration and fewer adverse effects. However, propranolol hydrochloride (BCS class I) is highly hydrophilic and has difficulty in penetrating the stratum corneum (SC) barrier. Dissolving microneedles (MNs) are an efficient tool for overcoming the barrier of the SC and enhancing dermal drug delivery. In this study, propranolol hydrochloride-loaded dissolving MNs were fabricated by using hyaluronic acid and polyvinyl pyrrolidone as matrix materials. Controllable drug loading in needle tips was achieved by a two-step casting procedure. The needles were good in mechanical strength for penetrating the SC while presented excellent dissolving capability for releasing propranolol hydrochloride. In comparison with the solution counterpart, irrespective of being applied to intact skin or solid MNs-pretreated skin, dissolving MNs significantly increased the permeability and skin retention of propranolol. In conclusion, dissolving MNs could be a potential approach for enhancing dermal delivery of propranolol to treat IH.

Enhancement strategies for transdermal drug delivery systems: current trends and applications

Transdermal drug delivery systems have become an intriguing research topic in pharmaceutical technology area and one of the most frequently developed pharmaceutical products in global market. The use of these systems can overcome associated drawbacks of other delivery routes, such as oral and parenteral. The authors will review current trends, and future applications of transdermal technologies, with specific focus on providing a comprehensive understanding of transdermal drug delivery systems and enhancement strategies. This article will initially discuss each transdermal enhancement method used in the development of first-generation transdermal products. These methods include drug/vehicle interactions, vesicles and particles, stratum corneum modification, energy-driven methods and stratum corneum bypassing techniques. Through suitable design and implementation of active stratum corneum bypassing methods, notably microneedle technology, transdermal delivery systems have been shown to deliver both low and high molecular weight drugs. Microneedle technology platforms have proven themselves to be more versatile than other transdermal systems with opportunities for intradermal delivery of drugs/biotherapeutics and therapeutic drug monitoring. These have shown that microneedles have been a prospective strategy for improving transdermal delivery systems.

Multifunctional Role of Polyvinylpyrrolidone in Pharmaceutical Formulations

Polyvinylpyrrolidone (PVP), a non-ionic polymer, has been employed in multifarious fields such as paper, fibers and textiles, ceramics, and pharmaceutics due to its superior properties. Especially in pharmacy, the properties of inertness, non-toxicity, and biocompatibility make it a versatile excipient for both conventional formulations and novel controlled or targeted delivery systems, serving as a binder, coating agent, suspending agent, pore-former, solubilizer, stabilizer, etc. PVP with different molecular weights (MWs) and concentrations is used in a variety of formulations for different purposes. In this review, PVP-related researches mainly in recent 10 years were collected, and its main pharmaceutical applications were summarized as follows: (i) improving the bioavailability and stability of drugs, (ii) improving the physicomechanical properties of preparations, (iii) adjusting the release rate of drugs, and (iv) prolonging the in vivo circulation time of liposomes. Most of these applications could be explained by the viscosity, solubility, hydrophilicity, and hydrogen bond-forming ability of PVP, and the specific action mechanisms for each application were also tried to figure out. The effect of PVP on bioavailability improvement establishes it as a promising polymer in the emerging controlled or targeted formulations, attracting growing interest on it. Therefore, given its irreplaceability and tremendous opportunities for future developments, this review aims to provide an informative reference about current roles of PVP in pharmacy for interested readers.

Microneedle Arrays Combined with Nanomedicine Approaches for Transdermal Delivery of Therapeutics

Organic and inorganic nanoparticles (NPs) have shown promising outcomes in transdermal drug delivery. NPs can not only enhance the skin penetration of small/biomacromolecule therapeutic agents but can also impart control over drug release or target impaired tissue. Thanks to their unique optical, photothermal, and superparamagnetic features, NPs have been also utilized for the treatment of skin disorders, imaging, and biosensing applications. Despite the widespread transdermal applications of NPs, their delivery across the stratum corneum, which is the main skin barrier, has remained challenging. Microneedle array (MN) technology has recently revealed promising outcomes in the delivery of various formulations, especially NPs to deliver both hydrophilic and hydrophobic therapeutic agents. The present work reviews the advancements in the application of MNs and NPs for an effective transdermal delivery of a wide range of therapeutics in cancer chemotherapy and immunotherapy, photothermal and photodynamic therapy, peptide/protein vaccination, and the gene therapy of various diseases. In addition, this paper provides an overall insight on MNs' challenges and summarizes the recent achievements in clinical trials with future outlooks on the transdermal delivery of a wide range of nanomedicines.

Biodegradable microneedles fabricated with carbohydrates and proteins: Revolutionary approach for transdermal drug delivery

There has been a surge in the use of transdermal drug delivery systems (TDDS) for the past few years. The market of TDDS is expected to reach USD 7.1 billion by 2023, from USD 5.7 billion in 2018, at a CAGR of 4.5%. Microneedles (MNs) are a novel class of TDDS with advantages of reduced pain, low infection risk, ease of application, controlled release of therapeutic agents, and enhanced bioavailability. Biodegradable MNs fabricated from natural polymers have become the center of attention among formulation scientists because of their recognized biodegradability, biocompatibility, ease of fabrication, and sustainable character. In this review, we summarize the various polysaccharides and polypeptide based biomaterials that are used to fabricate biodegradable MNs. Particular emphasis is given to cellulose and its derivatives, starch, and complex carbohydrate polymers such as alginates, chitosan, chondroitin sulfate, xanthan gum, pullulan, and hyaluronic acid. Additionally, novel protein-based polymers such as zein, collagen, gelatin, fish scale and silk fibroin (polyamino acid) biopolymers application in transdermal drug delivery have also been discussed. The current review will provide a unique perspective to the readers on the developments of biodegradable MNs composed of carbohydrates and protein polymers with their clinical applications and patent status.

Polymyxins and Bacterial Membranes: A Review of Antibacterial Activity and Mechanisms of Resistance

Following their initial discovery in the 1940s, polymyxin antibiotics fell into disfavor due to their potential clinical toxicity, especially nephrotoxicity. However, the dry antibiotic development pipeline, together with the rising global prevalence of infections caused by multidrug-resistant (MDR) Gram-negative bacteria have both rejuvenated clinical interest in these polypeptide antibiotics. Parallel to the revival of their use, investigations into the mechanisms of action and resistance to polymyxins have intensified. With an initial known effect on biological membranes, research has uncovered the detailed molecular and chemical interactions that polymyxins have with Gram-negative outer membranes and lipopolysaccharide structure. In addition, genetic and epidemiological studies have revealed the basis of resistance to these agents. Nowadays, resistance to polymyxins in MDR Gram-negative pathogens is well elucidated, with chromosomal as well as plasmid-encoded, transferrable pathways. The aims of the current review are to highlight the important chemical, microbiological, and pharmacological properties of polymyxins, to discuss their mechanistic effects on bacterial membranes, and to revise the current knowledge about Gram-negative acquired resistance to these agents. Finally, recent research, directed towards new perspectives for improving these old agents utilized in the 21st century, to combat drug-resistant pathogens, is summarized.

Polymyxin Delivery Systems: Recent Advances and Challenges

Polymyxins are vital antibiotics for the treatment of multiresistant Gram-negative ESKAPE pathogen infections. However, their clinical value is limited by their high nephrotoxicity and neurotoxicity, as well as their poor permeability and absorption in the gastrointestinal tract. This review focuses on various polymyxin delivery systems that improve polymyxin bioavailability and reduce drug toxicity through targeted and controlled release. Currently, the most suitable systems for improving oral, inhalation, and parenteral polymyxin delivery are polymer particles, liposomes, and conjugates, while gels, polymer fibers, and membranes are attractive materials for topical administration of polymyxin for the treatment of infected wounds and burns. In general, the application of these systems protects polymyxin molecules from the negative effects of both physiological and pathological factors while achieving higher concentrations at the target site and reducing dosage and toxicity. Improving the properties of polymyxin will be of great interest to researchers who are focused on developing antimicrobial drugs that show increased efficacy and safety.

Quantitation of polymeric-microneedle-delivered HA15 in tissues using liquid chromatography-tandem mass spectrometry

A rapid and sensitive liquid chromatography-tandem mass spectrometric method was developed and validated for the determination of HA15, an emerging anticancer compound targeting GSPA5/BIP delivered by dissolvable polymeric microneedles. The linear range of quantification for HA15 was 2.5-1000 ng/ml in plasma and tissue homogenate and the limit of detection and lower limit of quantification are 1 and 2.5 ng/ml, respectively. The inter- and intra-day accuracy and precision were within the acceptable range. HA15 was extracted from mouse plasma and organs using protein precipitation and using dabrafenib as an internal standard and the drug was stable under relevant analytical conditions. The method was used to analyze drug loading, dissolution in vitro, and release ex vivo from dissolvable polymeric microneedles and used to compare these materials to subcutaneous injection for the tissue distribution in tumor bearing nude mice.

Microneedles: a potential strategy in transdermal delivery and application in the management of psoriasis

Microneedles, as an updating approach delivering compounds through the skin, is potential in the management of psoriasis.

A Snapshot of Transdermal and Topical Drug Delivery Research in Canada

The minimally- or non-invasive delivery of therapeutic agents through the skin has several advantages compared to other delivery routes and plays an important role in medical care routines. The development and refinement of new technologies is leading to a drastic expansion of the arsenal of drugs that can benefit from this delivery strategy and is further intensifying its impact in medicine. Within Canada, as well, a few research groups have worked on the development of state-of-the-art transdermal delivery technologies. Within this short review, we aim to provide a critical overview of the development of these technologies in the Canadian environment.