Stratum Corneum Layer Of Skin Research Articles

Advancing psoriasis drug delivery through topical liposomes.

Psoriasis, recognized as a chronic inflammatory skin disorder, disrupts immune system functionality. Global estimates by the World Psoriasis Day consortium indicate its impact on approximately 130 million people, constituting 4 to 5 percent of the worldwide population. Conventional drug delivery systems, mainly designed to alleviate psoriasis symptoms, fall short in achieving targeted action and optimal bioavailability due to inherent challenges such as the drug's brief half-life, instability, and a deficiency in ensuring both safety and efficacy. Liposomes, employed indrug delivery systems, emerge as highly promising carriers for augmenting the therapeutic efficacy of topically applied drugs. These small unilamellar vesicles demonstrate enhanced penetration capabilities, facilitating drug delivery through the stratum corneum layer of skin. This comprehensive review article illuminates diverse facets ofliposomes as a promising drug delivery system to treat psoriasis. Addressing various aspects such as formulation strategies, encapsulation techniques, and targeted delivery, the review underscores the potential of liposomes in enhancing the efficacy and specificity of psoriasis treatments.

Deep Eutectic Solvent and Poly (Vinyl Alcohol) Based Self‐healable, Injectable and Adhesive „Eutectogel”: An Emerging Drug Delivery Vehicle

AbstractMultifunctional polymeric eutectogel with characteristics such as self‐healing, adhesive, moldable, load bearable and penetrable through the stratum corneum layer of skin is vital for designing highly efficient platform for the new age sustained transdermal drug delivery. Inspired by the sea cucumber, which can loosen and tighten its body and merge collagen fibers to regain firmness, a biomimetic multifunctional polymeric eutectogel with above mentioned characteristics is developed here through interacting natural deep eutectic solvent (NADES) with poly (vinyl alcohol) (PVA). Hydrogen bonding interactions responsible for the formation of eutectogel, its porous three‐dimensional fibrous network morphology and mechanical strength as well as thixotropic behavior were assessed using state of the art analytical techniques. The eutectogel also exhibited multifunctional properties such as phase transition, in‐vitro degradation and stability as a function of temperature, pH and salt concentration, respectively apart from its multifunctional characteristics. The eutectogel‐bound cotton patch with high absorptivity and stability (750 % high) of curcumin was developed. The eutectogel was further investigated for its potential as the transdermal delivery vehicle for the encapsulation and delivery of anticancer drug, 5‐Fluoro Uracil. Skin permeation study and chemotherapeutic activity against MCF‐07 human breast cancer cell lines were evaluated, showing promising results.

Formulation, optimization, and in-vitro evaluation of polymeric microsponges for topical delivery of vanillin

The development of ethylcellulose-based polymeric microsponges for the topical delivery of therapeutic agents has attracted the interest of pharmaceutical scientists around the globe in recent years. This work represents preparation, optimization (using Box–Behnken design [BBD]), and characterization (in-vitro and ex-vivo) of ethylcellulose microsponges loaded with vanillin for effective topical delivery to treat wounds. Vanillin-ethylcellulose microsponges were prepared by using quasi-emulsion solvent diffusion and optimized formulation (F9) (containing 100 mg ethylcellulose, 10 mL dichloromethane, 100 mg vanillin, and 90 mg polyvinyl alcohol) developed showed particle size (90.3 ± 2.9 µm), high entrapment of vanillin (79.0 ± 2.8%), and optimum colloidal properties (zeta potential = −37.91 ± 2.44 mV; polydispersity index (PDI) = 0.224 ± 0.23). Optimized formulation extended the release of vanillin (96.68 ± 3.11%) in-vitro for 24 h. Vanillin-ethylcellulose microsponges (F9) dispersed in Carbopol 940 gel showed limited ex-vivo skin permeation (steady-state flux, JSS = 243.7 ± 6.2 µg/cm2/h) and higher skin retention (82.46 ± 6.74%) for 24 h in pig ear skin compared to plain vanillin Carbopol 940 gel (steady-state flux, JSS = 1350 ± 10.8 µg/cm2/h, skin retention = 33.66 ± 4.53%). Results of confocal laser scanning microscopy (CLSM) of Vanillin-ethylcellulose microsponges (F9) Carbopol 940 gel revealed accumulation of microsponges in the stratum corneum layer of skin as a depot. Microsponges-based Carbopol 940 gel also displayed excellent in-vitro antibacterial activity (zone of inhibition = 24.2 ± 1.3 mm) against Staphylococcus aureus for 24 h compared to plain vanillin Carbopol 940 gel (zone of inhibition = 10.30 ± 1.2 mm) that was considered good for its wound healing activity. Therefore, developed vanillin-loaded ethylcellulose microsponges could be effectively used in the treatment of wounds by reducing side effects associated with vanillin and promoting its localized delivery in Carbopol 940 gel form.

Liposome Based Drug Delivery for the Management of Psoriasis - A Comprehensive Review.

Psoriasis has been considered as a chronic inflammatory skin disease which leads to the dysfunction of immune systems. According to the World Psoriasis Day consortium, psoriasis affects around 125 million individuals globally or about 2% to 3% of the overall population. Most of the conventional drug delivery systems primarily attempt to relieve symptoms of psoriasis and are ineffective in providing targeted action and higher bioavailability because of the drug's short half-life and instability, as well as they lack safety and efficacy. The shortcomings of conventional drug delivery systems give rise to the development of novel drug delivery systems which includes liposomes, transferosomes, ethosomes, niosomes, emulsomes, dendrimers, hydrogel, nanoparticles, etc. These novel formulations may enhance the therapeutic effects by changing physiological and pharmacokinetic parameters. Several research reports suggest that these novel drug delivery systems may enhance therapeutic effects which can be used as a promising approach for the treatment of psoriasis. The liposomes based drug delivery system have been considered as most promising vehicles for enhancing therapeutic potentials of drugs into or through the skin upon topical application. Liposomes have small unilamellar vesicles which may enhance the penetration ability through stratum corneum layer of skin. Therefore, present review article highlights on the different aspects of the liposomes as potential drug delivery system for the treatment of psoriasis.

Sugar-Triggered Burst Drug Releasing Poly-Lactic Acid (PLA) Microneedles and Its Fabrication Based on Solvent-Casting Approach.

Microneedles have emerged as a novel transdermal delivery tool that enables the delivery of various products such as drugs, vaccines, or cosmetic ingredients. Although the demand for solid microneedles composed of biocompatible polymer is increasing, the manufacture of microneedles using poly-lactic acid (PLA) with rapid drug-releasing is yet to be established and the process is still in its infancy. Here, we propose a novel strategy for the fabrication of PLA solid microneedles which enable a drug to be burst-released based on a solvent-casting process. This approach offers extreme simplicity, broad geometric capability, cost-effectiveness, and scalability based on high fidelity-replicas. It was verified that microneedles of various heights (250–500 μm) could be fabricated with appropriate mechanical strength to penetrate the stratum corneum layer of skin. By adding sugar in the composition of PLA microneedle, it was observed that both hydrophilic and hydrophobic drugs can be rapidly released within 30 min. Our burst drug-releasing PLA microneedle having both characteristics of solid microneedle and soluble microneedle and its fabrication approach based on solvent-casting will contribute to getting microneedle technology close to commercialization and beyond existing technical limitations.

Multiscale Simulation of Ternary Stratum Corneum Lipid Mixtures: Effects of Cholesterol Composition.

Molecular dynamics simulations of mixtures of the ceramide nonhydroxy-sphingosine (NS), cholesterol, and a free fatty acid are performed to gain molecular-level understanding of the structure of the lipids found in the stratum corneum layer of skin. A new coarse-grained force field for cholesterol was developed using the multistate iterative Boltzmann inversion (MS-IBI) method. The coarse-grained cholesterol force field is compatible with previously developed coarse-grained force fields for ceramide NS, free fatty acids, and water and validated against atomistic simulations of these lipids using the CHARMM force field. Self-assembly simulations of multilayer structures using these coarse-grained force fields are performed, revealing that a large fraction of the ceramides adopt extended conformations, which cannot occur in the single bilayer in water structures typically studied using molecular simulation. Cholesterol fluidizes the membrane by promoting packing defects, and an increase in cholesterol content is found to reduce the bilayer thickness due to an increase in interdigitation of the C24 lipid tails, consistent with experimental observations. Using a reverse-mapping procedure, a self-assembled coarse-grained multilayer system is used to construct an equivalent structure with atomistic resolution. Simulations of this atomistic structure are found to closely agree with experimentally derived neutron scattering length density profiles. Significant interlayer hydrogen bonding is observed in the inner layers of the atomistic multilayer structure that are not found in the outer layers in contact with water or in equivalent bilayer structures. This work highlights the importance of simulating multilayer structures, as compared to the more commonly studied bilayer systems, to enable more appropriate comparisons with multilayer experimental membranes. These results also provide validation of the efficacy of the MS-IBI derived coarse-grained force fields and the framework for multiscale simulation.

Ethosome: A Promising Approach for Antifungal Drug Delivery

Topical drug delivery system is most preferred drug delivery system. Various skin infections are treated by transdermal drug delivery system. Fungal infection on skin is most commonly found disease. To treat topical fungal infection many semisolid dosage forms like ointment, cream and gels are used. These formulations have limited therapeutic efficacy stability and safety profiles. Stratum corneum layer of skin acts as major barrier for topical formulation. Ethosomes are modified lipid carrier that helps drug to reach deep into skin. Ethosomes can be considered as one of the best replacement for carrying antifungal agent. Ethosomes contain phospholipids and high concentration of alcohol in vesicular formulation. An alcohol acts as permeation enhancer and increase permeability of skin.

Pharmacokinetics of the dermal route of exposure to volatile organic chemicals in water: A computer simulation model

A kinetic model of dermal absorption of nonpolar organic nonelectrolytes in dilute aqueous solutions is described. The model uses systems dynamics STELLA software and is designed for a Macintosh computer. The model assumes the outer stratum corneum layer of skin to be the rate-determining barrier to dermal absorption and assumes that both stratum corneum and viable epidermal layers have storage capacity for lipophilic solutes. The model predicts between 30 and 94% of experimental results with humans under the same conditions. The degree of departure between experimental and theoretical results is inversely related to the solute's octanol/water partition coefficient, which is consistent with the most recently hypothesized mechanisms of transport of molecules across the dermal barrier. The model has potentially useful applications for risk assessment if used within its defined limits.

PROTECTIVE ROLE OF BUTYLATED HYDROXYTOLUENE AND CERTAIN CAROTENOIDS IN PHOTOCARCINOGENESIS*

Butylated hydroxytoluene (BHT) and certain carotenoid pigments have been found to inhibit photocarcinogenesis in animal models. In addition, BHT protects against UV-B-induced erythema and UV-B induction of ornithine decarboxylase. Studies on the photoprotective mechanism(s) of BHT suggested that changes in the physico-chemical properties of the keratin of the stratum corneum layer of skin occurred, leading to increases in UV absorption of that tissue. These changes might be exerted via the anti-radical action of BHT that retards oxidation and prevents cross-linking of the keratin chains, resulting in a diminution of UV-B radiation reaching potential target sites. The carotenoids beta-carotene, canthaxanthin and phytoene also inhibit UV-B carcinogenesis. beta-Carotene and canthaxanthin are excellent quenchers of singlet oxygen, and all three pigments can quench free radicals. beta-Carotene and canthaxanthin have been shown to quench singlet oxygen/free radical reactions in the skin of porphyric mice, and these two pigments as well as phytoene have been found to quench excited species formed on irradiation of mouse skin by UV-B.

PROTECTIVE ROLE OF BUTYLATED HYDROXYTOLUENE AND CERTAIN CAROTENOIDS IN PHOTOCARCINOGENESIS

Abstract— Butylated hydroxytoluene (BHT) and certain carotenoid pigments have been found to inhibit photocarcinogenesis in animal models. In addition, BHT protects against UV-B-induced erythema and UV-B induction of ornithine decarboxylase. Studies on the photoprotective mechanism(s) of BHT suggested that changes in the physico-chemical properties of the keratin of the stratum corneum layer of skin occurred, leading to increases in UV absorption of that tissue. These changes might be exerted via the anti-radical action of BHT that retards oxidation and prevents cross-linking of the keratin chains, resulting in a diminution of UV-B radiation reaching potential target sites. The carotenoids β-carotene, canthaxanthin and phytoene also inhibit UV-B carcinogenesis. β-Carotene and canthaxanthin are excellent quenchers of singlet oxygen, and all three pigments can quench free radicals. β-Carotene and canthaxanthin have been shown to quench singlet oxygen/free radical reactions in the skin of porphyric mice, and these two pigments as well as phytoene have been found to quench excited species formed on irradiation of mouse skin by UV-B.