Epidermal Delivery of Retinyl Palmitate Loaded Transfersomes: Penetration and Biodistribution Studies

Alpha-Tocopherol-Infused Flexible Liposomal Nanocomposite Pressure-Sensitive Adhesive: Enhancing Skin Permeation of Retinaldehyde

Retinaldehyde (RAL), or retinal, is a vitamin A derivative that is widely used for several skin conditions. However, it is light sensitive and has low water solubility, limiting its efficiency in transdermal delivery. This study developed a novel delivery system for retinal (RAL) using flexible liposomes (FLPs) infused with α-tocopherol succinate (α-TS) to improve stability, and enhance skin permeability. The RAL-FLPs were embedded in pressure-sensitive adhesive (PSA) hydrogels, creating a delivery platform that supports prolonged skin residence and efficient permeation of RAL. The stability and skin permeation as well as human skin irritation and adhesion capabilities were assessed to determine the formulation's safety and efficacy. Our findings suggested that the addition of α-TS could improve liposomal stability and RAL chemical stability. Moreover, the skin permeation and fluorescence microscopic-based studies suggested that the addition of α-TS could enhance skin permeability of RAL through hair follicles. The RAL-FLP was embedded in PSA hydrogels fabricated from 25% GantrezTM S-97 (GT) and 1% hyaluronic acid (Hya) with aluminum as a crosslinker. The PSA hydrogel exhibited desirable peeling and tacking strengths. The developed hydrogels also demonstrated greater skin deposition of RAL compared with its aqueous formulation. Additionally, the RAL-FLP-embedded PSA hydrogels showed no skin irritation and maintained better adhesion for up to 24 h compared to commercial patches. Hence, the developed hydrogels could serve as a beneficial platform for delivering RAL in treating skin conditions.

Retinol semisolid preparations in cosmetics: transcutaneous permeation mechanism and behaviour

Retinol is widely used to treat skin ageing because of its effect on cell differentiation, proliferation and apoptosis. However, its potential benefits appear to be limited by its skin permeability. Herein, we investigated the transcutaneous behavior of retinol in semisolid cosmetics, in both in vitro and in vivo experiments. In vitro experiments used the modified Franz diffusion cell combined with Raman spectroscopy. In in vivo experiments, the content of retinol in rat skin and plasma was detected with HPLC. Retinol in semisolid cosmetics was mainly concentrated in the stratum corneum in the skin of the three animal models tested, and in any case did not cross the skin barrier after a 24 h dermatologic topical treatment in Franz diffusion cells tests. Similar results were obtained in live mice and rats, where retinol did not cross the skin barrier and did not enter the blood circulation. Raman spectroscopy was used to test the penetration depth of retinol in skin, which reached 16 μm out of 34 μm in pig skin, whereas the skin of mouse and rat showed too strong bakground interference. To explore epidermal transport mechanism and intradermal residence, skin transcriptomics was performed in rats, which identified 126 genes upregulated related to retinol transport and metabolism, relevant to the search terms "retinoid metabolic process" and "transporter activity". The identity of these upregulated genes suggests that the mechanism of retinol action is linked to epidermis, skin, tissue and epithelium development.

The effect of skin diffusion kinetics of isopropyl ester permeation enhancers on drug permeation: Role of lateral spread and penetration characteristics

The purpose of present work was to study the effects of permeation enhancers' two kinetic behaviors of simultaneous lateral diffusion and vertical penetration in the skin on its enhancing effect. The skin diffusion kinetics of isopropyl ester permeation enhancers were characterized by the innovative concentric tape peeling study and Raman imaging, which were quantitatively assessed through innovative parameters, namely, lateral-to-vertical penetration amount (CL-V) and lateral-to-vertical penetration distance (DL-V). The enhancement effect of permeation enhancers on drug flurbiprofen (FLU) was assessed by in vitro skin permeation tests, which were confirmed by transdermal water loss and skin resistance study. The relationship between kinetic parameters of permeation enhancers and permeation parameters of FLU was carried out by correlation analysis. The molecular mechanisms of effect of skin diffusion kinetics of permeation enhancers on drug permeation were characterized by molecular docking, modulated-temperature differential scanning calorimetry (MTDSC), Raman spectra, solid-state NMR and molecular dynamic simulation. The results indicated skin diffusion kinetics of short-chain (C8-C12) isopropyl ester permeation enhancers were governed by vertical penetration, while long-chain (C14-C18) ones were characterized by lateral spread. Quadratic correlation between CL-V and enhancement ratio of permeation-retention ratio of FLU (ERQ/R) (R2 = 0.95), DL-V and enhancement ratio of permeation area (ERA) of FLU (R2 = 0.98) indicating that varied skin diffusion kinetics of permeation enhancers directly influenced the barrier function of stratum corneum (SC) and further enhancing drug permeation. In terms of molecular mechanism, long-chain isopropyl ester enhancers had good miscibility with SC, leading to their high CL-V and DL-V, and causing strong interaction strength with SC and resulting in weaker skin barrier function for drug permeation. In summary, in comparison to short-chain isopropyl ester enhancers that relied on penetration, long-chain ones that depended on lateral spread exhibited greater enhancement efficacy, which guided the application of enhancers in transdermal formulations.

Fabrication and application of targeted ciprofloxacin nanocarriers for the treatment of chronic bacterial prostatitis

Pathogenic bacteria cause chronic bacterial prostatitis (CBP). CPB is characterized by urinary tract infection and persistence of pathogenic bacteria in prostatic secretion. Owing to poor blood supply to the prostate gland and limited drug penetration, CBP treatment is difficult. Transferosomes are ultradeformable vesicles for nanocarrier applications, which have become an important area of nanomedicine. Such carriers are specifically targeted to the pathological area to provide maximum therapeutic efficacy. It consists of a lipid bilayer soybean lecithin phosphatidylcholine (PC), an edge activator Tween 80 with various ratios, and a chloroform/methanol core. Depending on the lipophilicity of the active substance, it can be encapsulated within the core or among the lipid bilayer. Due to their exceptional flexibility, which enables them to squeeze themselves through narrow pores that are significantly smaller than their size, they can be a solution. One formulation (Cipro5 PEG) was selected for further in vitro analysis and was composed of phosphatidylcholine (PC), Tween 80, and polyethylene glycol-6 stearate (PEG-6 stearate) in a ratio of 3:3:1 in a chloroform/methanol mixture (1:2 v/v). In vitro, the results showed that PEGylated transferosomes had faster drug release, higher permeation, and increased bioavailability. The transferosomes were quantified with a particle size of 202.59 nm, a zeta potential of-49.38 mV, and a drug entrapment efficiency of 80.05%. The aim of this study was to investigate drug targeting. Therefore, Monoclonal antibody IgG was coupled with Cipro5 PEG, which has specificity and selectivity for conjugated nanoparticles. In vivo, a total of twenty-five adult Wistar rats were obtained and randomly divided into 5 groups, each of 5 rats at random: the control group, blank group, positive control group, Cipro 5PEG group, and Cipro 5PEG coupled with IgG antibody group. The cytokines levels (IL-1β, IL-8, and TNF-α) in the serum were detected by analysis kits. Compared with the control group, treatment with Cipro 5PEG coupled with the IgG antibody could significantly inhibit cytokines, according to histological analysis. Cipro 5PEG, coupled with the IgG antibody group, reduced prostate tissue inflammation. Hence, our results show a promising approach to delivering antibiotics for the targeted therapy of CBP.

Super-Antioxidant Vitamin A Derivatives with Improved Stability and Efficacy Using Skin-Permeable Chitosan Nanocapsules

Retinyl palmitate (RP) is a retinol ester with strong antioxidant and anti-inflammatory properties as an antiwrinkle agent. However, it has poor aqueous solubility and easily degrades into inactive forms for topical applications. Therefore, we developed chitosan-coated nanocapsules (ChiNCs) to encapsulate RP using a simple nanoprecipitation method for protection against physiological conditions and to enable deep skin penetration. The as-prepared RP-loaded nanocapsules (RP@ChiNCs) loaded with approximately 5 wt.% RP exhibited a hydrodynamic diameter of 86 nm and surface charge of 24 mV. They had adequate stability to maintain their physicochemical properties after lyophilization in a biological buffer. Notably, ChiNCs provided RP with remarkable protection against degradation for 4 weeks at 37 °C. Thus, RP@ChiNCs exhibited good antioxidant activity in situ for sufficiently long periods without considerable changes in their efficacy. Furthermore, ChiNCs enhanced the skin penetration of lipophilic RP based on the inherent nature of chitosan. RP@ChiNCs exhibited good in vitro antioxidant and anti-inflammatory effects without causing any cytotoxicity in dermal fibroblasts. Accordingly, they promoted cell proliferation in a wound-scratch test and enhanced collagen synthesis. These results suggest that RP@ChiNCs are promising candidates for cosmetic and biomedical applications.

L-Cysteine-Modified Transfersomes for Enhanced Epidermal Delivery of Podophyllotoxin

The purpose of this study was to evaluate L-cysteine-modified transfersomes as the topical carrier for enhanced epidermal delivery of podophyllotoxin (POD). L-cysteine-deoxycholic acid (LC-DCA) conjugate was synthesized via an amidation reaction. POD-loaded L-cysteine-modified transfersomes (POD-LCTs) were prepared via a thin membrane dispersion method and characterized for their particle size, zeta potential, morphology, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and in vitro release. Subsequently, in vitro skin permeation and retention, fluorescence distribution in the skin, hematoxylin-eosin staining and in vivo skin irritation were studied. The POD-LCTs formed spherical shapes with a particle size of 172.5 ± 67.2 nm and a zeta potential of -31.3 ± 6.7 mV. Compared with the POD-Ts, the POD-LCTs provided significantly lower drug penetration through the porcine ear skin and significantly increased the skin retention (p < 0.05). Meaningfully, unlike the extensive distribution of the POD-loaded transfersomes (POD-Ts) throughout the skin tissue, the POD-LCTs were mainly located in the epidermis. Moreover, the POD-LCTs did not induce skin irritation. Therefore, the POD-LCTs provided an enhanced epidermal delivery and might be a promising carrier for the topical delivery of POD.

Latanoprost-Loaded Nanotransfersomes Designed for Scalp Administration Enhance Keratinocytes Proliferation

Latanoprost (LAT) has been shown to have a hypertrichotic effect, which makes it a promising candidate for alopecia treatments. For the first time, LAT has been encapsulated in nanotransfersomes in order to increase its efficacy. Ex vivo skin biodistribution was studied by confocal laser microscopy both in human scalp and pig skin. Results showed that nanotransfersomes increase the penetration of two different fluorochromes, with similar patterns in both species, compared with fluorochrome solutions containing no nanotransfersomes. Nanotransfersomes were stable under accelerated conditions (40 °C/75% RH) and long-term conditions (25 °C/60% RH) for up to 1 year, with no differences in vesicle size and polydispersity when LAT was loaded. Nanotransfersomes increased the LAT cell proliferation effect in HaCaT cell via MAPK signaling pathway. Collectively, our results demonstrate LAT-nanotransfersomes formulation could be a promising therapy for hair growth disorders.

Preparation, Characterization and Permeation Study of Topical Gel Loaded with Transfersomes Containing Asiatic Acid

The objective of this study is to investigate the in vitro permeation of asiatic acid (AA) in the form of a topical gel after entrapment in transfersomes by Franz diffusion cells. Transfersomes composed of soybean lecithin and three different edge activators including Tween 80 (TW80), Span 80 (SP80) and sodium deoxycholate (SDC) at the ratio of 50:50, 90:10 and 90:10, respectively, together with 0.3% w/w of AA, were prepared by a high-pressure homogenization technique and further incorporated in gels (TW80AATG, SP80AATG and SDCAATG). All transfersomal gels were characterized for their AA contents, dynamic viscosity, pH and homogeneity. Results revealed that the AA content, dynamic viscosity and pH of the prepared transfersomal gels ranged from 0.272 ± 0.006 to 0.280 ± 0.005% w/w, 812.21 ± 20.22 to 1222.76 ± 131.99 Pa.s and 5.94 ± 0.03 to 7.53 ± 0.03, respectively. TW80AATG gave the highest percentage of AA penetration and flux into the Strat-M^® membrane at 8 h (8.53 ± 1.42% and 0.024 ± 0.008 mg/cm²/h, respectively) compared to SP80AATG (8.00 ± 1.70% and 0.019 ± 0.010 mg/cm²/h, respectively), SDCAATG (4.80 ± 0.50% and 0.014 ± 0.004 mg/cm²/h, respectively), non-transfersomal gels (0.73 ± 0.44 to 3.13 ± 0.46% and 0.002 ± 0.001 to 0.010 ± 0.002 mg/cm²/h, respectively) and hydroethanolic AA solution in gel (1.18 ± 0.76% and 0.004 ± 0.003 mg/cm²/h, respectively). These findings indicate that the TW80AATG might serve as a lead formulation for further development toward scar prevention and many types of skin disorders.

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.

Development of Stable Nano-Sized Transfersomes as a Rectal Colloid for Enhanced Delivery of Cannabidiol

Current cannabidiol (CBD) formulations are challenged with unpredictable release and absorption. Rational design of a rectal colloid delivery system can provide a practical alternative. In this study the inherent physiochemical properties of transferosomes were harnessed for the development of a nano-sized transfersomes to yield more stable release, absorption, and bioavailability of CBD as a rectal colloid. Transfersomes composed of soya lecithin, cholesterol, and polysorbate 80 were synthesized via thin film evaporation and characterized for size, entrapment efficiency (%), morphology, CBD release, ex vivo permeation, and physicochemical stability. The optimized formulation for rectal delivery entrapped up to 80.0 ± 0.077% of CBD with a hydrodynamic particle size of 130 nm, a PDI value of 0.285, and zeta potential of −15.97 mV. The morphological investigation via SEM and TEM revealed that the transfersomes were spherical and unilamellar vesicles coinciding with the enhanced ex vivo permeation across the excised rat colorectal membrane. Furthermore, transfersomes improved the stability of the encapsulated CBD for up to 6 months at room temperature and showed significant promise that the transfersomes promoted rectal tissue permeation with superior stability and afforded tunable release kinetics of CBD as a botanical therapeutic with inherent poor bioavailability.

Use of Retinoids in Topical Antiaging Treatments: A Focused Review of Clinical Evidence for Conventional and Nanoformulations

Nowadays, numerous skincare routines are used to rejuvenate aging skin. Retinoids are one of the most popular ingredients used in antiaging treatments. Among the representatives of retinoids, tretinoin is considered the most effective agent with proven antiaging effects on the skin and can be found in formulations approved as medicines for topical treatment of acne, facial wrinkles, and hyperpigmentation. Other retinoids present in topical medicines are used for various indications, but only tazarotene is also approved as adjunctive agent for treatment of facial fine wrinkling and pigmentation. The most commonly used retinoids such as retinol, retinaldehyde, and retinyl palmitate are contained in cosmeceuticals regulated as cosmetics. Since clinical efficacy studies are not required for marketing cosmetic formulations, there are concerns about the efficacy of these retinoids. From a formulation perspective, retinoids pose a challenge to researchers as a result of their proven instability, low penetration, and potential for skin irritation. Therefore, novel delivery systems based on nanotechnology are being developed to overcome the limitations of conventional formulations and improve user compliance. In this review, the clinical evidence for retinoids in conventional and nanoformulations for topical antiaging treatments was evaluated. In addition, an overview of the comparison clinical trials between tretinoin and other retinoids is presented. In general, there is a lack of evidence from properly designed clinical trials to support the claimed efficacy of the most commonly used retinoids as antiaging agents in cosmeceuticals. Of the other retinoids contained in medicines, tazarotene and adapalene have clinically evaluated antiaging effects compared to tretinoin and may be considered as potential alternatives for antiaging treatments. The promising potential of retinoid nanoformulations requires a more comprehensive evaluation with additional studies to support the preliminary findings.

Lipid-Based Nanovesicular Drug Delivery Systems

In designing a new drug, considering the preferred route of administration, various requirements must be fulfilled. Active molecules pharmacokinetics should be reliable with a valuable drug profile as well as well-tolerated. Over the past 20 years, nanotechnologies have provided alternative and complementary solutions to those of an exclusively pharmaceutical chemical nature since scientists and clinicians invested in the optimization of materials and methods capable of regulating effective drug delivery at the nanometer scale. Among the many drug delivery carriers, lipid nano vesicular ones successfully support clinical candidates approaching such problems as insolubility, biodegradation, and difficulty in overcoming the skin and biological barriers such as the blood-brain one. In this review, the authors discussed the structure, the biochemical composition, and the drug delivery applications of lipid nanovesicular carriers, namely, niosomes, proniosomes, ethosomes, transferosomes, pharmacosomes, ufasomes, phytosomes, catanionic vesicles, and extracellular vesicles.

Transfersomes: a Revolutionary Nanosystem for Efficient Transdermal Drug Delivery

Transdermal delivery system has gained significance in drug delivery owing to its advantages over the conventional delivery systems. However, the barriers of stratum corneum along with skin irritation are its major limitations. Various physical and chemical techniques have been employed to alleviate these impediments. Among all these, transfersomes have shown potential for overcoming the associated limitations and successfully delivering therapeutic agents into systemic circulation. These amphipathic vesicles are composed of phospholipids and edge activators. Along with providing elasticity, edge activator also affects the vesicular size and entrapment efficiency of transfersomes. The mechanism behind the enhanced permeation of transfersomes through the skin involves their deformability and osmotic gradient across the application site. Permeation enhancers can further enhance their permeability. Biocompatibility; capacity for carrying hydrophilic, lipophilic as well as high molecular weight therapeutics; deformability; lesser toxicity; enhanced permeability; and scalability along with potential for surface modification, active targeting, and controlled release render them ideal designs for efficient drug delivery. The current review provides a brief account of the discovery, advantages, composition, synthesis, comparison with other cutaneous nano-drug delivery systems, applications, and recent developments in this area.

Self-Assembling Drug Formulations with Tunable Permeability and Biodegradability

This review focuses on key topics in the field of drug delivery related to the design of nanocarriers answering the biomedicine criteria, including biocompatibility, biodegradability, low toxicity, and the ability to overcome biological barriers. For these reasons, much attention is paid to the amphiphile-based carriers composed of natural building blocks, lipids, and their structural analogues and synthetic surfactants that are capable of self-assembly with the formation of a variety of supramolecular aggregates. The latter are dynamic structures that can be used as nanocontainers for hydrophobic drugs to increase their solubility and bioavailability. In this section, biodegradable cationic surfactants bearing cleavable fragments are discussed, with ester- and carbamate-containing analogs, as well as amino acid derivatives received special attention. Drug delivery through the biological barriers is a challenging task, which is highlighted by the example of transdermal method of drug administration. In this paper, nonionic surfactants are primarily discussed, including their application for the fabrication of nanocarriers, their surfactant-skin interactions, the mechanisms of modulating their permeability, and the factors controlling drug encapsulation, release, and targeted delivery. Different types of nanocarriers are covered, including niosomes, transfersomes, invasomes and chitosomes, with their morphological specificity, beneficial characteristics and limitations discussed.

Ultradeformable vesicles: concepts and applications relating to the delivery of skin cosmetics

Skin aging is a phenomenon resulting in reduced self-confidence, thus becoming a major factor in social determinants of health. The use of active cosmetic ingredients can help prevent skin aging. Transfersomes are well known to be capable of deeply penetrating the dermis. This scoping review provides an insight into transfersomes and their prospective use in anti-aging cosmetics. Numerous reports exist highlighting the successful skin delivery of therapeutic agents such as high-molecular-weight, poorly water soluble and poorly permeable active ingredients by means of transfersomes. Moreover, in vitro and in vivo studies have indicated that transfersomes increase the deposition, penetration and efficacy of active ingredients. However, the use of transfersomes in the delivery of active cosmetic ingredients is limited. Considering their similar physicochemical properties, transfersomes should possess considerable potential as a delivery system for anti-aging cosmetics.

A Comprehensive Review on Preparation, Evaluation and Applications of Deformable Liposomes

Elastic or deformable liposomes are phospholipid-based vesicular drug delivery systems that help improve the delivery of therapeutic agents through the intact skin membrane due to their deformable characteristics that overcome the problems of conventional liposomes. In the present review, different types of deformable liposomes such as transfersomes, ethosomes, menthosomes, invasomes and transethosome are studied, and their mechanism of action, characterization, preparation methods, and applications in pharmaceutical technology through topical, transdermal, nasal and oral routes for effective drug delivery are compared for their potential transdermal delivery of poorly permeable drugs. Due to the deformable characteristics of these vehicles, it resulted in modulation of increased drug encapsulation efficiency, permeation and penetration of the drug into or through the skin membrane and are found to be more effective than conventional drug delivery systems. So deformable liposomes can, therefore, be considered as a promising way of delivering the drugs transdermally.

Cationic liposomes mediated transdermal delivery of meloxicam and ketoprofen: Optimization of the composition, in vitro and in vivo assessment of efficiency

New liposomes modified with pyrrolidinium surfactants containing a hydroxyethyl fragment (C_nPB, n = 12, 14, 16) were prepared for transdermal delivery of non-steroidal anti-inflammatory drugs. In order to obtain the optimal composition, the surfactant/lipid molar ratio (0.02/1; 0.029/1; 0.04/1) and the amphiphile hydrocarbon tail length were varied. Rhodamine B was loaded in all formulations, while meloxicam and ketoprofen in selected ones. For liposomes studied the hydrodynamic diameter was in the range of 80-130 nm, the zeta potential ranged from +35 to +50 mV, EE was 75-99%. Liposome modification leads to a prolonged release of the rhodamine B (up to 10-12 h) and faster release of non-steroidal drugs (up to 7-8 h) in vitro. The ability to cross the skin barrier using Franz cells was investigated for liposomal meloxicam and ketoprofen. The total amount of meloxicam and ketoprofen passed through the Strat-M® membranes during 51 h was 51-114 μg/cm² and 87-105 μg/cm² respectively. The evaluation of transdermal diffusion ex vivo showed that total amount of liposomal ketoprofen passed through the skin during 51 h was 140-162 μg/cm². Liposomes modified with C₁₆PB were found as the most effective inflammation reducing formulation in the carrageenan edema model of rat paw.

Dexamethasone-Loaded Lipomers: Development, Characterization, and Skin Biodistribution Studies

Follicular targeting has gained more attention in recent decades, due to the possibility of obtaining a depot effect in topical administration and its potential as a tool to treat hair follicle-related diseases. Lipid core ethyl cellulose lipomers were developed and optimized, following which characterization of their physicochemical properties was carried out. Dexamethasone was encapsulated in the lipomers (size, 115 nm; polydispersity, 0.24; zeta-potential (Z-potential), +30 mV) and their in vitro release profiles against dexamethasone in solution were investigated by vertical diffusion Franz cells. The skin biodistribution of the fluorescent-loaded lipomers was observed using confocal microscopy, demonstrating the accumulation of both lipomers and fluorochromes in the hair follicles of pig skin. To confirm this fact, immunofluorescence of the dexamethasone-loaded lipomers was carried out in pig hair follicles. The anti-inflammatory (via TNFα) efficacy of the dexamethasone-loaded lipomers was demonstrated in vitro in an HEK001 human keratinocytes cell culture and the in vitro cytotoxicity of the nanoformulation was investigated.

Lipid vesicles: A versatile drug delivery platform for dermal and transdermal applications

Topical and transdermal application of active pharmaceutical ingredients to the skin is an attractive strategy being explored by formulation scientists to treat disease conditions rather than the oral drug delivery. Several approaches have been attempted, and many of them have emerged with significant clinical potential. However, the delivery of drugs across the skin is an arduous task due to permeation limiting barriers. It, therefore, requires the aid of external agents or carrier systems for efficient permeation. Lipid-based vesicular systems are carriers for the transport of drugs through the stratum corneum (dermal drug delivery) and into the bloodstream for systemic action (transdermal drug delivery) overcoming the barrier properties. This review article describes the various vesicular systems reported for skin delivery of actives with relevant case studies. The vesicular systems presented here are in the order of their advent from conventional systems to the advanced lipid vesicles. The design and development of drugs in vesicular systems have brought a new dimension to the treatment of disease conditions overcoming the permeation limiting barriers, thus improving its efficacy.

Phospholipid Vesicles for Dermal/Transdermal and Nasal Administration of Active Molecules: The Effect of Surfactants and Alcohols on the Fluidity of Their Lipid Bilayers and Penetration Enhancement Properties

This is a comprehensive review on the use of phospholipid nanovesicles for dermal/transdermal and nasal drug administration. Phospholipid-based vesicular carriers have been widely investigated for enhanced drug delivery via dermal/transdermal routes. Classic phospholipid vesicles, liposomes, do not penetrate the deep layers of the skin, but remain confined to the upper stratum corneum. The literature describes several approaches with the aim of altering the properties of these vesicles to improve their penetration properties. Transfersomes and ethosomes are the most investigated penetration-enhancing phospholipid nanovesicles, obtained by the incorporation of surfactant edge activators and high concentrations of ethanol, respectively. These two types of vesicles differ in terms of their structure, characteristics, mechanism of action and mode of application on the skin. Edge activators contribute to the deformability and elasticity of transfersomes, enabling them to penetrate through pores much smaller than their own size. The ethanol high concentration in ethosomes generates a soft vesicle by fluidizing the phospholipid bilayers, allowing the vesicle to penetrate deeper into the skin. Glycerosomes and transethosomes, phospholipid vesicles containing glycerol or a mixture of ethanol and edge activators, respectively, are also covered. This review discusses the effects of edge activators, ethanol and glycerol on the phospholipid vesicle, emphasizing the differences between a soft and an elastic nanovesicle, and presents their different preparation methods. To date, these differences have not been comparatively discussed. The review presents a large number of active molecules incorporated in these carriers and investigated in vitro, in vivo or in clinical human tests.

Recent Advances in the Structural Design of Photosensitive Agent Formulations Using "Soft" Colloidal Nanocarriers

The growing demand for effective delivery of photosensitive active compounds has resulted in the development of colloid chemistry and nanotechnology. Recently, many kinds of novel formulations with outstanding pharmaceutical potential have been investigated with an expansion in the design of a wide variety of "soft" nanostructures such as simple or multiple (double) nanoemulsions and lipid formulations. The latter can then be distinguished into vesicular, including liposomes and "smart" vesicles such as transferosomes, niosomes and ethosomes, and non-vesicular nanosystems with solid lipid nanoparticles and nanostructured lipid carriers. Encapsulation of photosensitive agents such as drugs, dyes, photosensitizers or antioxidants can be specifically formulated by the self-assembly of phospholipids or other amphiphilic compounds. They are intended to match unique pharmaceutic and cosmetic requirements and to improve their delivery to the target site via the most common, i.e., transdermal, intravenous or oral administration routes. Numerous surface modifications and functionalization of the nanostructures allow increasing their effectiveness and, consequently, may contribute to the treatment of many diseases, primarily cancer. An increasing article number is evidencing significant advances in applications of the different classes of the photosensitive agents incorporated in the "soft" colloidal nanocarriers that deserved to be highlighted in the present review.

Chitosan and phospholipid assisted topical fusidic acid drug delivery in burn wound: Strategies to conquer pharmaceutical and clinical challenges, opportunities and future panorama

Burn is the immense public health issue globally. Low and middle income countries face extensive deaths owing to burn injuries. Availability of conventional therapies for burns has always been painful for patients as well as expensive for our health system. Pharmaceutical experts are still searching reliable, cheap, safe and effective treatment options for burn injuries. Fusidic acid is an antibiotic of choice for the management of burns. However, fusidic acid is encountering several pharmaceutical and clinical challenges like poor skin permeability and growing drug resistance against burn wound microbes like Methicillin resistant Staphylococcus aureus (MRSA). Therefore, an effort has been made to present a concise review about molecular pathway followed by fusidic acid in the treatment of burn wound infection in addition to associated pros and cons. Furthermore, we have also summarized chitosan and phospholipid based topical dermal delivery systems customized by our team for the delivery of fusidic acid in burn wound infections on case-to-case basis. However, every coin has two sides. We recommend the integration of in-silico docking techniques with natural biomacromolecules while designing stable, patient friendly and cost effective topical drug delivery systems of fusidic acid for the management of burn wound infection as future opportunities.

Topical Delivery of Meloxicam using Liposome and Microemulsion Formulation Approaches

The aim of this study is to develop, characterize and compare conventional liposome, deformable liposome (transfersome) and microemulsion formulations as potential topical delivery systems for meloxicam. Liposomes were characterized in terms of vesicle size, zeta potential and entrapment efficiency. For microemulsions, particle size, electrical conductivity and viscosity studies were performed to assess the structure of the investigated systems. An ex vivo skin permeation study has been conducted to compare these formulations. The dermal and transdermal delivery of meloxicam using these formulations can be a promising alternative to conventional oral delivery of non-steroidal anti-inflammatory drugs (NSAIDs) with enhanced local and systemic onset of action and reduced side effects.