Transdermal Drug Administration Research Articles

The Design Features, Quality by Design Approach, Characterization, Therapeutic Applications, and Clinical Considerations of Transdermal Drug Delivery Systems—A Comprehensive Review

Transdermal drug delivery systems (TDDSs) are designed to administer a consistent and effective dose of an active pharmaceutical ingredient (API) through the patient’s skin. These pharmaceutical preparations are self-contained, discrete dosage forms designed to be placed topically on intact skin to release the active component at a controlled rate by penetrating the skin barriers. The API provides the continuous and prolonged administration of a substance at a consistent rate. TDDSs, or transdermal drug delivery systems, have gained significant attention as a non-invasive method of administering APIs to vulnerable patient populations, such as pediatric and geriatric patients. This approach is considered easy to administer and helps overcome the bioavailability issues associated with conventional drug delivery, which can be hindered by poor absorption and metabolism. A TDDS has various advantages compared to conventional methods of drug administration. It is less intrusive, more patient-friendly, and can circumvent first pass metabolism, as well as the corrosive acidic environment of the stomach, that happens when drugs are taken orally. Various approaches have been developed to enhance the transdermal permeability of different medicinal compounds. Recent improvements in TDDSs have enabled the accurate administration of APIs to their target sites by enhancing their penetration through the stratum corneum (SC), hence boosting the bioavailability of drugs throughout the body. Popular physical penetration augmentation methods covered in this review article include thermophoresis, iontophoresis, magnetophoresis, sonophoresis, needle-free injections, and microneedles. This review seeks to provide a concise overview of several methods employed in the production of TDDSs, as well as their evaluation, therapeutic uses, clinical considerations, and the current advancements intended to enhance the transdermal administration of drugs. These advancements have resulted in the development of intelligent, biodegradable, and highly efficient TDDSs.

Design Principles and Applications of Ionic Liquids for Transdermal Drug Delivery.

Ionic liquids (ILs) are salts with melting points typically <100°C, composed of specific anions and cations. Recently, IL application has expanded into material engineering and biomedicine. Due to their unique properties, ILs have garnered significant interest in pharmacological research as solubilizers, transdermal absorption enhancers, antibacterial agents, and stabilizers of insoluble pharmaceutical active ingredients. The improvement of skin permeability by ILs is closely associated with their specific physicochemical characteristics, which are identified by their ionic composition. However, the existing literature on transdermal medication administration is insufficient in terms of a comprehensive knowledge base. This review provides a comprehensive assessment of the design principles involved in IL synthesis. Additionally, it discusses the methods utilized to assess skin permeability and provides a focused outline of IL application in transdermal drug administration.

Studies on drug delivery from dissolving microneedle and its uptake in tissue

Abstract In this study, a mathematical model for transdermal drug administration using a dissolving conical microneedle (MN) is developed. The drug is absorbed in the blood compartment after passing through the skin's viable epidermis. Reversible reaction kinetics then allow the drug to enter the tissue compartment. An unsteady reaction equation is used to predict the drug's distribution into the skin following MN's dissolution. An unsteady reaction mechanism is used to determine the concentrations in the blood and tissue compartments. Using the fourth-order Runge-Kutta method, the governing equations with their initial conditions are solved numerically. The MN is expected to dissolve completely in 108.1 seconds, according to the predicted results, while the concentration in the skin peaks at 94.4 seconds. The concentrations in the tissue and blood compartments, however, reach their respective maximal amounts later on. In this investigation, the impacts of the drug's mass fraction, volume fraction, and penetration rate cannot be completely ruled out. A thorough sensitivity analysis has been carried out for some of the parameters involved. Our findings closely align with the findings reported in the literature.

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.

Direct 3D printing of triple-responsive nanocomposite hydrogel microneedles for controllable drug delivery

Hydrogel microneedle patches have emerged as promising platforms for painless, minimally invasive, safe, and portable transdermal drug administration. However, the conventional mold-based fabrication processes and inherent single-functionality of such microneedles present significant hurdles to broader implementation. Herein, we have developed a novel approach utilizing a precursor solution of robust nanocomposite hydrogels to formulate photo-printable inks suitable for the direct 3D printing of high-precision, triple-responsive hydrogel microneedle patches through digital light processing (DLP) technology. The ink formulation comprises four functionally diverse monomers including 2-(dimethylamino)ethyl methacrylate, N-isopropylacrylamide, acrylic acid, and acrylamide, which were crosslinked by aluminum hydroxide nanoparticles (AH NPs) acting as both reinforcing agents and crosslinking centers. This results in the formation of a nanocomposite hydrogel characterized by exceptional mechanical strength, an essential attribute for the 3D printing of hydrogel microneeedle patches. Furthermore, this innovative 3D printing strategy facilitates facile customization of microneedle geometry and patch dimensions. As a proof-of-concept, we employed the fabricated hydrogel microneedles for transdermal delivery of bovine serum albumin (BSA). Importantly, these hydrogel microneedles displayed no cytotoxic effects and exhibited triple sensitivity to pH, temperature and glucose levels, thereby enabling more precise on-demand drug delivery. This study provides a universal method for the rapid fabrication of hydrogel microneedles with smart responsiveness for transdermal drug delivery applications.

Fabrication and Synthesis of Thiococlchicoside Loaded Matrix Type Transdermal Patch.

The goal of this work was to synthesize and fabricate matrix type transdermal patches based on a combination of polymers (Eudragit L100, HPMC and PVP K30), plasticizer and crosslinking agents (propylene glycol and triethyl citrate) and adhesives (Dura Tak 87-6908) to increase Thiocolchicoside (THC) absorption via topical route. This method allows avoidance of first-pass metabolism along with a consistent and extended duration of therapeutic activity. Fabrication and casting of polymeric solutions containing THC was done either in petri plates or through lab coater to get transdermal patches. Finally, the formulated patches were studied for their physicochemical and biological evaluation using scanning electron microscopy, FTIR, DSC, XRD and ex-vivo permeation studies using pig ear skin. FTIR studies confirm that the THC characteristics peaks (carbonyl (Amide I) at 1525.5 cm-1, C=O stretching (tropane ring) at 1664.4 cm-1, Amide II band (N-H stretching) at 3325.9 cm-1, thioether band at 2360.7 cm-1, and OH group stretching band at 3400.2 cm-1) are still present in the polymer mixture even after formulation as a transdermal patch, indicating compatibility among all excipients. While on the other hand, DSC studies confirm endothermic peaks for all the polymers along with THC with the highest enthalpy of 65.979 J/g, which is an indicator of sharp endothermic peak at 198°C, leading to the melting of THC. The percentage drug content and percentage moisture uptake of all the formulation was found in the range of 96 ± 2.04 to 98.56 ± 1.34% and 4.13 ± 1.16 to 8.23 ± 0.90%, respectively. Drug release and release kinetics studies confirm that it is dependent on the composition of individual formulation. All these findings support the possibility of using suitable polymeric composition, as well as proper formulation and manufacturing circumstances, to create a one-of-a-kind technology platform for transdermal drug administration.

3D printing redefines microneedle fabrication for transdermal drug delivery.

Microneedles (MNs) have emerged as an innovative, virtually painless technique for intradermal drug delivery. However, the complex and costly fabrication process has limited their widespread accessibility, especially for individuals requiring frequent drug administration. This study introduces a groundbreaking and cost-effective method for producing MNs utilizing fused deposition modeling (FDM) 3D printing technology to enhance transdermal drug delivery. The proposed fabrication process involves the elongation of molten polylactic acid (PLA) filaments to create meticulously designed conoid and neiloid MNs with smooth surfaces. This study underscores the critical role of printing parameters, particularly extrusion length and printing speed, in determining the shape of the MNs. Notably, the conoid-shaped MNs exhibit exceptional skin-penetrating capabilities. In order to evaluate their effectiveness, the MNs were tested on a polydimethylsiloxane (PDMS) skin model for skin penetration. The results highlight the high potential of 3D-printed MNs for transdermal drug administration. This novel approach capitalizes on the benefits of 3D printing technology to fabricate MNs that hold the promise of transforming painless drug administration for a variety of medical applications.

Skin Penetrating Lipid Vesicles: Ethosomes in Drug Delivery and Cosmeceuticals

Ethosomes, or skin penetrating lipid vesicles, are proving to be effective delivery systems for cosmetics and pharmaceuticals. This article thoroughly examines ethosomes, including their structure, formulation methods, characterization tactics, and skin penetration mechanisms. Ethosomes are able to deform and penetrate the stratum corneum thanks to their special lipid compositions and elasticity, which let them get around obstacles in transdermal drug administration and cosmeceutical application. The selection of lipids, surfactants, and active compounds for ethosome formulations, as well as the function of ethanol as a penetration enhancer, are covered in detail in the current article. The discussion of various production processes and characterization methodologies emphasizes the significance of size distribution, zeta potential, and encapsulation effectiveness. The review investigates the mechanisms through which ethosomes interact with the stratum corneum and other skin barriers and the variables affecting the effectiveness and depth of their transdermal administration. The applications of ethosomes in the delivery of both hydrophilic and lipophilic medicines and their promise in targeted and localized treatments highlight their adaptability. The clinical implications are discussed, illuminating preclinical and clinical research that highlight the improved efficacy and safety of formulations based on ethosomes. Ethosomes provide a platform for improving the distribution of active substances like vitamins, antioxidants, and peptides in the field of cosmeceuticals. Their uses encompass topical formulations for skin whitening, hydration, rejuvenation, and antiaging and skin care products. The paper also discusses future directions in ethosome research, such as customized medicine and combination medicines, as well as regulatory issues and difficulties with commercialization.

A bio-ionic liquid based self-healable and adhesive ionic hydrogel for the on-demand transdermal delivery of a chemotherapeutic drug.

The non-invasive nature and potential for sustained release make transdermal drug administration an appealing treatment option for cancer therapy. However, the strong barrier of the stratum corneum (SC) poses a challenge for the penetration of hydrophilic chemotherapy drugs such as 5-fluorouracil (5-FU). Due to its biocompatibility and capacity to increase drug solubility and permeability, especially when paired with chemical enhancers, such as oleic acid (OA), which is used in this work, choline glycinate ([Cho][Gly]) has emerged as a potential substance for transdermal drug delivery. In this work, we examined the possibility of transdermal delivery of 5-FU for the treatment of breast cancer using an ionic hydrogel formulation consisting of [Cho][Gly] with OA. Small angle neutron scattering, rheological analysis, field emission scanning electron microscopy, and dynamic light scattering analysis were used to characterize the ionic hydrogel. The non-covalent interactions present between [Cho][Gly] and OA were investigated by computational simulations and FTIR spectroscopy methods. When subjected to in vitro drug permeation using goat skin in a Franz diffusion cell, the hydrogel demonstrated sustained release of 5-FU and effective permeability in the order: [Cho][Gly]-OA gel > [Cho][Gly] > PBS (control). The hydrogel also demonstrated 92% cell viability after 48 hours for the human keratinocyte cell line (HaCaT cells) as well as the normal human cell line L-132. The breast cancer cell line MCF-7 and the cervical cancer cell line HeLa were used to study in vitro cytotoxicity that was considerably affected by the 5-FU-loaded hydrogel. These results indicate the potential of the hydrogel as a transdermal drug delivery vehicle for the treatment of breast cancer.

Wetting and Adhesive Properties of Biopolymer-Based Organized Condensed Phases as Drug Delivery Systems

Lyotropic liquid crystalline systems are of great interest as carriers of biological substances for targeted delivery, mainly for transdermal administration of drugs and their application to the skin and mucous membranes. The wetting and adhesive interactions of lyomesophases and gel based on a chitosan polysaccharide in lactic acid solution on a glass substrate (base surface) and the surface of a semi-permeable polytetrafluoroethylene membrane (model of epidermis horny layer) were studied. The effect of the riboflavin drug (vitamin B2) on the surface tension of studied samples and the amount of adhesion work has been established. It is shown that biocompatible chitosan-containing systems can be used as drug carriers for various biomedical purposes, including transdermal drug delivery.

Smart Responsive Microneedles for Controlled Drug Delivery.

As an emerging technology, microneedles offer advantages such as painless administration, good biocompatibility, and ease of self-administration, so as to effectively treat various diseases, such as diabetes, wound repair, tumor treatment and so on. How to regulate the release behavior of loaded drugs in polymer microneedles is the core element of transdermal drug delivery. As an emerging on-demand drug-delivery technology, intelligent responsive microneedles can achieve local accurate release of drugs according to external stimuli or internal physiological environment changes. This review focuses on the research efforts in smart responsive polymer microneedles at home and abroad in recent years. It summarizes the response mechanisms based on various stimuli and their respective application scenarios. Utilizing innovative, responsive microneedle systems offers a convenient and precise targeted drug delivery method, holding significant research implications in transdermal drug administration. Safety and efficacy will remain the key areas of continuous efforts for research scholars in the future.

A CONCISE OUTLINE ON INNOVATIVE PERMEATION ENHANCERS IN TRANSDERMAL DRUG DELIVERY APPROACH

The transdermal drug administration system represents a potent substitute for administering medications orally and is also designed to offer a substitute for hypodermic injections. Presently, three generations of penetration enhancer to permeate through skin are available 1st Generation embraces chemical approaches and pertain to augment the efficacy of the drug transferred across the integral skin, 2nd generation encompasses physical permeation technologies and 3rd generation consists of microneedle and needleless penetration enhancers. There is renewed interest in transdermal drug delivery. This review focuses on some existing novel approaches and the additive upshot of techniques for increasing the permeation of drugs via skin penetration. By using the right methods, drug carriers, or certain chemical agents, it is important to cause the stratum corneum to change physically or biomolecularly.

Antioxidant Activity of Quercetin-Containing Liposomes-in-Gel and Its Effect on Prevention and Treatment of Cutaneous Eczema.

Cutaneous eczema is a kind of skin disease is characterized by inflammation. The main manifestations are various types of dermatitis, eczema, and urticaria. There are usually complications such as erythema, blisters, and epidermal peeling. The quercetin might have a therapeutic effect on cutaneous eczema due to its favorable antioxidant activity and anti-inflammatory effects. Currently, there are few studies on transdermal administration of antioxidant drugs for the treatment of cutaneous eczema. The aim of this study was to prepare quercetin-containing liposomes-in-gel (QU-LG), its antioxidant properties were evaluated, and it was used in the skin of mice suffering from dermal eczema to see if it had preventive and therapeutic effects in an attempt to make it a new option for the treatment of cutaneous eczema. QU-LG was prepared by the injection method to form the quercetin-containing liposomes (QU-L) and evenly dispersed in the natural dissolution of carboxymethylcellulose sodium (1%, CMC-Na). The release of QU-LG across the dialysis membranes was up to 30% and clearance of 1,1-diphenyl-2-picrylhydrazyl (DPPH) was 65.16 ± 3.513%. In anti-oxidation assay QU-LG inhibited malondialdehyde (MDA) production in liver better than the commercially available drug dexamethasone acetate cream. Compared with untreated mice, mice treated with QU-LG showed a statistically significant reduction in dermatopathologic symptoms. The results suggested that QU-LG had good antioxidant activity in vivo and in vitro and could be used for the prevention and treatment of cutaneous eczema.

Strategies for Improving Transdermal Administration: New Approaches to Controlled Drug Release.

In this work, we aim to address several strategies to improve transdermal drug delivery, such as iontophoresis, sonophoresis, electroporation and micron. We also propose a review of some transdermal patches and their applications in medicine. TDDs (transdermal patches with delayed active substances) are multilayered pharmaceutical preparations that may contain one or more active substances, of which, systemic absorption is achieved through intact skin. The paper also presents new approaches to the controlled release of drugs: niosomes, microemulsions, transfersomes, ethosomes, but also hybrid approaches nanoemulsions and microns. The novelty of this review lies in the presentation of strategies to improve the transdermal administration of drugs, combined with their applications in medicine, in light of pharmaceutical technological developments.

Microneedles : A Smart Approach for Transdermal Drug Delivery System

Due to the limitations of oral and parenteral medication delivery, which result in patient noncompliance, the Novel Drug Delivery System is currently more effective than the Conventional Drug Delivery System. The transdermal drug administration method is frequently used to deliver medications through the skin for both local and systemic effects. The stratum corneum's epidermal layer serves as a significant barrier for the transport of drugs via the skin. We can release a medicine by various techniques in a regulated manner with the aid of different sorts of microneedle patches on the skin, depending on the microneedle's design. Microneedles are made from a range of materials, including silicon, stainless steel, polymers, metals, and carbohydrates. These materials have been utilised to create coated, solid, dissolving, hollow, and hydrogel-forming microneedles. These microneedles transport different medications, proteins, vaccines, and immunobiological substances, and they are crucial in the treatment of many illnesses like cancer, diabetes, and pain management. The development of the microneedle faces numerous problems, including those related to stability, dosage accuracy, skin irritation cost, and more. The types, fabrication materials and processes, and applications of the microneedle drug delivery system are discussed in this review.

Effect of an Oxygen-Based Mechanical Drug Delivery System on Percutaneous Permeation of Various Substances In Vitro.

Transdermal drug administration is an elegant method to overcome various side effects of oral or parenteral drug administration. Nevertheless, due to an effective skin barrier, which is provided by the stratum corneum, transdermal drug delivery is sometimes very slow and ineffective. Thus, the effect of a medical device (DERMADROP TDA) for transdermal penetration of drugs in conjunction with a special vehicle emulsion on percutaneous permeation of several substances (with different physicochemical properties) was investigated in Franz-type diffusion cells with porcine skin over 28 h. This medical device disperses pharmaceutical agents via oxygen flow through an application system, which is used in conjunction with specially developed vehicle substances. Substance permeation of various substances with different physicochemical properties (diclofenac, enrofloxacin, flufenamic acid, indomethacin, and salicylic acid) was examined after application with a pipette and with the medical device. Therefore, acceptor media samples were collected up to 28 h after drug administration. Drug concentration in the acceptor medium was determined via high-performance liquid chromatography. Enhanced permeation was observed for diclofenac, enrofloxacin, flufenamic acid, indomethacin, and salicylic acid after oxygen-based administration. This correlates negatively with the molecular weight. Thus, drug administration can effectively be enhanced by a medical device using oxygen.

Pareto chart‐enabled screening of influential factors in designing transfersomes

AbstractMethotrexate is the treatment of choice for rheumatoid arthritis, having significant side effects on oral administration, prompting researchers to consider transdermal administration. Transfersomes can overcome the challenges of transdermal administration of drugs because of their deformable nature, allowing for greater skin penetration than other formulations. However, due to an enormous number of product and process variables, the manufacturing of transfersomes proved a pain. The goal of the research study was to use a Plackett‐Burman design to evaluate an important product and process variables connected with the preparation of methotrexate transfersomes. The influence of six product and process variables on %entrapment efficiency and vesicle deformability was investigated and according to p‐values, and the Pareto chart, the concentration of lipid, edge activator, and methotrexate were found critical variables influencing vesicle features having positive and negative effects on variables. In the future, experimental design may be used to optimize these critical parameters for further exploration in the development of methotrexate transfersomes.

Effect of microneedles shape on skin penetration and transdermal drug administration

Microneedle (MN) patches are highly efficient and versatile tools for transdermal drug administration, in particular for pain-free, self-medication and rapid local applications. Diffraction ultraviolet (UV) light lithography offers an advanced method in fabricating poly(ethylene glycol)-based MNs with different shapes, by changing both the UV-light exposure time and photomask design. The exposure time interval is limited at obtaining conical structures with aspect ratio < 1:3, otherwise MNs exhibit reduced fracture load and poor indentation ability, not suitable for practical application. Therefore, this work is focused on a systematic analysis of the MN's base shapes effects on the structural characteristics, skin penetration and drug delivery. Analyzing four different base shapes (circle, triangle, square and star), it has been found that the number of vertices in the polygon base heavily affects these properties. The star-like MNs reveal the most efficient skin penetration ability (equal to 40 % of -their length), due to the edges action on the skin during the perforation. Furthermore, the quantification of the drug delivered by the MNs through ex-vivo porcine skin shows that the amounts of small molecules released over 24 h by star-like MNs coated by local anesthetic (Lidocaine) and an anti-inflammatory (Diclofenac epolamine) drugs are 1.5× and 2× higher than the circular-MNs, respectively.

Characterizations of Liquid Crystals as A Transdermal Drug Delivery System

The outermost layer of skin, the stratum corneum, has a role as the primary barrier against water evaporation from the body and drug entry through skin into the body. Thus, overcoming the stratum corneum barrier is important to develop transdermal drug delivery systems. Transdermal administration of drugs represents an excellent alternative to conventional pharmaceutical dosage forms. However, insufficient penetration of the active pharmaceutical substance through the skin is a common problem. Thus, in the present review we discussed the characterizations and the skin permeation enhancing ability of liquid crystal (LC) topical formulations.

Dielectric and calorimetric study in renewable polymer blends based on poly(ethylene adipate) and poly(lactic acid) with microphase separation

A series of sustainable polymeric blends based on poly(lactic acid) (PLA) and poly(ethylene adipate) (PEAd), are studied herein, from the point of view of thermal transitions, crystallization and molecular mobility. The blending aims at the manipulation of the chains' mobility and crystallization of PLA, as PEAd exhibits quite lower glass transition temperature and is expected to act as plasticizer. In a next step, such systems are envisaged for use as patches for transdermal administration of antimicrobial drugs, formed as fibril-systems via the electrospinning technique. For the present work, we have employed calorimetry and the advanced technique of dielectric spectroscopy as main investigation tools, which are supplemented by polarized microscopy. Regarding molecular mobility, the overall dynamics (local and segmental) map was constructed for these systems, for the first time. The presence of PEAd imposed plasticization on the PLA chains, as manifested by the lowering of Tg and acceleration of segmental dynamics. On the other hand, PEAd is deplasticized at the presence of PLA. In addition, the fragility of PLA chains drops at the presence of PEAd, suggesting increasing in the cooperativity length, or else, a chain-chain detaching. The overall data are also indicative of the partially miscible polymers. Regarding crystallization, neat PLA exhibits neither hot nor cold crystallization, whereas, strikingly, with the addition of PEAd, the nucleation of PLA is facilitated and strong cold crystallization is systematically recorded. The phenomenon seems to be connected with both the plasticization of the PLA chains along with the homogeneous microphase separation of the two polymers (partial immiscibility), overall, with size-effects. Local dynamics, originating from more localized molecular motions, exhibit systematic alternation in the blends in both the time scale and dielectric strength. Our results show that the PLA/PEAd blends are ‘phase change materials’ with potentials to tune the materials performance, connected, among others, with the semicrystalline morphology and the interchain distances.