The effect of non-invasive dermal electroporation on skin barrier function and skin permeation in combination with different dermal formulations

Peptides: Emerging Candidates for the Prevention and Treatment of Skin Senescence: A Review

One class of cosmetic compounds that have raised interest of many experts is peptides. The search for ingredients with good biocompatibility and bioactivity has led to the use of peptides in cosmetic products. Peptides are novel active ingredients that improve collagen synthesis, enhance skin cell proliferation, or decrease inflammation. Based on their mechanism of action, they can be classified into signal peptides, carrier peptides, neurotransmitter inhibitor peptides, and enzyme inhibitor peptides. This review focuses on the main types of peptides and their application in the cosmetic field, underlining their main limitations. One of the most significant drawbacks of cosmetic peptides is their poor permeability through membranes, which limits their delivery and effectiveness. As a result, this review follows the methods used for improving permeability through the stratum corneum. Increasing peptide bioavailability and stability for enhanced delivery to the desired site of action and visible effects have become central points for the latest research due to their promising features. For this purpose, several methods have been identified and described. Physical techniques include thermal ablation (radiofrequency and laser), electrical methods (electroporation, iontophoresis), mechanical approach (microneedles), and ultrasounds. As an alternative, innovative formulations have been developed in nano-systems such as liposomes, niosomes, ethosomes, nanoemulsions, and other nanomaterials to reduce skin irritation and improve product effectiveness. The purpose of this review is to provide the latest information regarding these noteworthy molecules and the reasoning behind their use in cosmetic formulations.

Clinical evaluation of liposome-based gel formulation containing glycolic acid for the treatment of photodamaged skin

Background: Long contact of UV causes skin damage. Glycolic acid (GA) as an alpha hydroxy acid is used to treat photodamaged skin. However, GA leads to side effects including; burning, erythema and peeling.Purpose: The aim of this study was to develop a controlled delivery systems loading GA in order to increasing its efficacy and lowering its side effects.Methods: Liposomes were evaluated for encapsulation efficiency, size and morphology. Optimized formulation was dispersed in HPMC gel bases and drug release kinetics were also studied. Clinical efficacy and safety of GA-loaded liposomal gel and GA gel formulation were evaluated in patients with photodamaged skin.Results: The EE% and average particle size of liposomes were 64 ±2.1 % and 317±3.6 nm, respectively. SEM image showed that liposomes were spherical in shape. In vitro release kinetics of GA from both formulations followed Weibull model. Clinical evaluation revealed that GA-loaded liposomal gel was more effective than GA gel formulation. Treatment with GA-loaded liposomal gel resulted in a statistically significant reduction in the scores of hyperpigmentation, fine wrinkling and lentigines. Moreover, liposomal gel formulation was able to minimize side effects of GA.Conclusion: According to the obtained results, the liposome-based gel formulation can be used as potential drug delivery system to enhance permeation of GA through skin layers and also reduce its side effects.

Topical Nanoliposomal Collagen Delivery for Targeted Fibril Formation by Electrical Stimulation

Collagen is a complex, large protein molecule that presents a challenge in delivering it to the skin due to its size and intricate structure. However, conventional collagen delivery methods are either invasive or may affect the protein's structural integrity. This study introduces a novel approach involving the encapsulation of collagen monomers within zwitterionic nanoliposomes, termed Lip-Cols, and the controlled formation of collagen fibrils through electric fields (EF) stimulation. The results reveal the self-assembly process of Lip-Cols through electroporation and a pH gradient change uniquely triggered by EF, leading to the alignment and aggregation of Lip-Cols on the electrode interface. Notably, Lip-Cols exhibit the capability to direct the orientation of collagen fibrils within human dermal fibroblasts. In conjunction with EF, Lip-Cols can deliver collagen into the dermal layer and increase the collagen amount in the skin. The findings provide novel insights into the directed formation of collagen fibrils via electrical stimulation and the potential of Lip-Cols as a non-invasive drug delivery system for anti-aging applications.

Skin electroporation for transdermal drug delivery: Electrical measurements, numerical model and molecule delivery

Skin electroporation for drug delivery involves the application of Pulsed Electric Fields (PEFs) on the skin to disrupt its barrier function in a temporary and non-invasive manner, increasing the uptake of drugs. It represents a potential alternative to delivery methods that are invasive (e.g. injections) or limited. We have developed a drug delivery system comprising nanocomposite hydrogels which act as a reservoir for the drug and an electrode for applying electric pulses on the skin. In this study, we employed a multi-scale approach to investigate the drug delivery system on a mouse skin model, through electrical measurements, numerical modeling and fluorescence microscopy. The Electrical properties indicated a highly non-linear skin conductivity behavior and were used to fine-tune the simulations and study skin recovery after electroporation. Simulation of electric field distribution in the skin showed amplitudes in the range of reversible tissue electroporation (400-1200 V/cm), for 300 V PEF. Fluorescence microscopy revealed increased uptake of fluorescent molecules compared to the non-pulsed control. We reported two reversible electroporation domains for our configuration: (1) at 100 V PEF the first local transport regions appear in the extracellular lipids of the stratum corneum, demonstrated by a rapid increase in the skin's conductivity and an increased uptake of lucifer yellow, a small hydrophilic fluorophore and (2) at 300 V PEF, the first permeabilization of nucleated cells occurred, evidenced by the increased fluorescence of propidium iodide, a membrane-impermeable, DNA intercalating agent.

Advancements in Skin-Mediated Drug Delivery: Mechanisms, Techniques, and Applications

Skin-mediated drug delivery methods currently are receiving significant attention as a promising approach for the enhanced delivery of drugs through the skin. Skin-mediated drug delivery offers the potential to overcome the limitations of traditional drug delivery methods, including oral administration and intravenous injection. The challenges associated with drug permeation through layers of skin, which act as a major barrier, are explored, and strategies to overcome these limitations are discussed in detail. This review categorizes skin-mediated drug delivery methods based on the means of increasing drug permeation, and it provides a comprehensive overview of the mechanisms and techniques associated with these methods. In addition, recent advancements in the application of skin-mediated drug delivery are presented. The review also outlines the limitations of ongoing research and suggests future perspectives of studies regarding the skin-mediated delivery of drugs.

Foams Set a New Pace for the Release of Diclofenac Sodium

Medicated foams have emerged as promising alternatives to traditional carrier systems in pharmaceutical research. Their rapid and convenient application allows for effective treatment of extensive or hirsute areas, as well as sensitive or inflamed skin surfaces. Foams possess excellent spreading capabilities on the skin, ensuring immediate drug absorption without the need for intense rubbing. Our research focuses on the comparison of physicochemical and biopharmaceutical properties of three drug delivery systems: foam, the foam bulk liquid, and a conventional hydrogel. During the development of the composition, widely used diclofenac sodium was employed. The safety of the formulae was confirmed through an in vitro cytotoxicity assay. Subsequently, the closed Franz diffusion cell was used to determine drug release and permeation in vitro. Ex vivo Raman spectroscopy was employed to investigate the presence of diclofenac sodium in various skin layers. The obtained results of the foam were compared to the bulk liquid and to a conventional hydrogel. In terms of drug release, the foam showed a rapid release, with 80% of diclofenac released within 30 min. In summary, the investigated foam holds promising potential as an alternative to traditional dermal carrier systems, offering faster drug release and permeation.

The Effect of Sun Tan Lotion on Skin by Using Skin TEWL and Skin Water Content Measurements

Stratum corneum (SC) is the outermost skin layer. SC hydration is important for its cosmetic properties and barrier function. SC trans-epidermal water loss (TEWL) measurements and skin water content measurements are two key indexes used for SC characterisation. The instrument stability and accuracy are vitally important when measuring small changes. In this paper, we present our latest study on the effect of sun tan lotion on skin by using skin TEWL and skin water content measurements. We developed techniques to improve the measurement stability and to visualise small changes, as well as developed machine learning algorithms for processing the skin capacitive images. The overall results show that TEWL and skin water content measurements are capable of measuring the subtle changes of skin conditions due to the application of sun tan lotions. The results show that the TEWL values decreased after the sun tan lotion application. The sun tan lotion with SPF 20 had the lowest decrease, whilst the sun tan lotion with SPF 50+ had the highest decrease. The results also show that the skin water content increased after the sun tan lotion application, with SPF 20 having the highest increase, whilst SPF 50+ had the lowest increase.