Inhibition of skin inflammation in mice by diclofenac in vesicular carriers: Liposomes, ethosomes and PEVs

Characterization Methods for Nanoparticle-Skin Interactions: An Overview

Research progresses have led to the development of different kinds of nanoplatforms to deliver drugs through different biological membranes. Particularly, nanocarriers represent a precious means to treat skin pathologies, due to their capability to solubilize lipophilic and hydrophilic drugs, to control their release, and to promote their permeation through the stratum corneum barrier. A crucial point in the development of nano-delivery systems relies on their characterization, as well as in the assessment of their interaction with tissues, in order to predict their fate under in vivo administration. The size of nanoparticles, their shape, and the type of matrix can influence their biodistribution inside the skin strata and their cellular uptake. In this respect, an overview of some characterization methods employed to investigate nanoparticles intended for topical administration is presented here, namely dynamic light scattering, zeta potential, scanning and transmission electron microscopy, X-ray diffraction, atomic force microscopy, Fourier transform infrared and Raman spectroscopy. In addition, the main fluorescence methods employed to detect the in vitro nanoparticles interaction with skin cell lines, such as fluorescence-activated cell sorting or confocal imaging, are described, considering different examples of applications. Finally, recent studies on the techniques employed to determine the nanoparticle presence in the skin by ex vivo and in vivo models are reported.

Engineering aspects of lipid-based delivery systems: In vivo gene delivery, safety criteria, and translation strategies

Defects in the genome cause genetic diseases and can be treated with gene therapy. Due to the limitations encountered in gene delivery, lipid-based supramolecular colloidal materials have emerged as promising gene carrier systems. In their non-functionalized form, lipid nanoparticles often demonstrate lower transgene expression efficiency, leading to suboptimal therapeutic outcomes, specifically through reduced percentages of cells expressing the transgene. Due to chemically active substituents, the engineering of delivery systems for genetic drugs with specific chemical ligands steps forward as an innovative strategy to tackle the drawbacks and enhance their therapeutic efficacy. Despite intense investigations into functionalization strategies, the clinical outcome of such therapies still needs to be improved. Here, we highlight and comprehensively review engineering aspects for functionalizing lipid-based delivery systems and their therapeutic efficacy for developing novel genetic cargoes to provide a full snapshot of the translation from the bench to the clinics. We outline existing challenges in the delivery and internalization processes and narrate recent advances in the functionalization of lipid-based delivery systems for nucleic acids to enhance their therapeutic efficacy and safety. Moreover, we address clinical trials using these vectors to expand their clinical use and principal safety concerns.

Design, Formulation, and Characterization of Valsartan Nanoethosomes for Improving Their Bioavailability

The objective of this study was to formulate and evaluate valsartan (VLT) ethosomes to prepare an optimized formula of VLT-entrapped ethosomes that could be incorporated into a sustained release transdermal gel dosage form. The formulation of the prepared ethosomal gel was investigated and subjected to in vitro drug release studies, ex vivo test, and in vivo studies to assess the effectiveness of ethosomal formulation in enhancing the bioavailability of VLT as a poorly soluble drug and in controlling its release from the transdermal gel dosage form. The acquired results are as follows: Dependent responses were particle size, polydispersity index, zeta potential, and entrapment efficiency. The optimized VLT-ETHs had a nanometric diameter (45.8 ± 0.5 nm), a negative surface charge (-51.4 ± 6.3 mV), and a high drug encapsulation (94.24 ± 0.2). The prepared VLT ethosomal gel (VLT-ethogel) showed a high peak plasma concentration and enhanced bioavailability in rats compared with the oral solution of valsartan presented in the higher AUC (0-∞). The AUC (0-∞) with oral treatment was 7.0 ± 2.94 (μg.h/mL), but the AUC (0-∞) with topical application of the VAL nanoethosomal gel was 137.2 ± 49.88 (μg.h/mL), providing the sustained release pattern of VLT from the tested ethosomal gel.

Ultraflexible Liposome Nanocargo as a Dermal and Transdermal Drug Delivery System

A selected active pharmaceutical ingredient must be incorporated into a cargo carrier in a particular manner so that it achieves its goal. An amalgamation of active pharmaceutical ingredients (APIs) should be conducted in such a manner that it is simple, professional, and more beneficial. Lipids/polymers that are known to be used in nanocarriers for APIs can be transformed into a vesicular formulation, which offers elegant solutions to many problems. Phospholipids with other ingredients, such as ethanol and water, form suitable vesicular carriers for many drugs, overcoming many problems related to poor bioavailability, poor solubility, etc. Ultraflexible liposomes are novel carriers and new frontiers of drug delivery for transdermal systems. Auxiliary advances in vesicular carrier research have been made, enabling polymer-coated ethanolic liposomes to avoid detection by the body’s immune system—specifically, the cells of the reticuloendothelial system. Ultraflexible liposomes act as a cargo system and a nanotherapeutic approach for the transport of therapeutic drugs and bioactive agents. Various applications of liposome derivatives in different diseases are emphasized in this review.

Use of 18β-glycyrrhetinic acid nanocrystals to enhance anti-inflammatory activity by improving topical delivery

18β-Glycyrrhetinic acid (GA) is often topically applied in clinical treatment of inflammatory skin diseases. However, GA has poor solubility in water, which results in poor skin permeability and low bioavailability. Nanocrystallization of drugs can enhance their permeability and improve bioavailability. We prepared GA nanocrystals (Nano GA) by high-pressure homogenization. These nanocrystals were characterized by photon correlation spectroscopy, scanning electron microscopy, thermogravimetric analysis, and X-ray diffractometry. The ability of Nano GA to improve dermal permeability was investigated ex vivo using Franz diffusion vertical cells and mouse skin. The topical anti-inflammatory activity of Nano GA was assessed in vivo by a 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced model in mouse ears. The average particle size of a GA nanocrystalline suspension was 288.6 ± 7.3 nm, with a narrow particle-size distribution (polydispersity index ∼0.13 ± 0.10), and the particle size of the lyophilized powder increased (552.0 ± 9.8 nm). After nanocrystallization, the thermal stability and crystallinity decreased but solubility increased significantly. Nano GA showed higher dermal permeability than Coarse GA. Macroscopic and staining-based observations of mouse ears and the levels of proinflammatory factors and myeloperoxidase revealed that the Nano GA hydrogel exhibited better anti-edema ability and more strongly inhibited inflammation development than the Coarse GA hydrogel and indomethacin hydrogel (positive drug). These results suggest that Nano GA could be an efficacious topical therapeutic agent for skin inflammation.

Exploration of Nanoethosomal Transgel of Naproxen Sodium for the Treatment of Arthritis

BACKGROUND

The present work aimed to develop an ethosomal gel of naproxen sodium for the amelioration of rheumatoid arthritis.

OBJECTIVE

In the present work, we have explored the potential of ethosomes to deliver naproxen into deeper skin strata. Further, the anti-inflammatory efficacy of naproxen ethosomal formulation was assessed using the carrageenan-induced rat paw edema model.

METHODS

Naproxen sodium nanoethosomes were prepared using different proportions of lipoid S100 (50mg-200mg), ethanol (20-50%) and water, and were further characterized on the basis of vesicle morphology, entrapment efficiency, zeta potential, in-vitro drug release and ex-vivo permeation studies.

RESULTS

The optimized ethosomal formulation was found to have 129 ± 0.01 nm particle size, 0.295 Polydispersity Index (PDI), -3.29 mV zeta potential, 88% entrapment efficiency and 96.573% drug release in 24 hours. TEM and SEM analysis of the optimized formulation showed slightly smooth spherical structures. The Confocal laser scanning microscopy showed that ethosomes could easily infiltrate into deeper dermal layers (upto 104.9μm) whereas the hydroalcoholic solution of the drug could penetrate up to 74.9μm. Further, the optimized ethosomal formulation was incorporated into 1% carbopol 934 gel base and optimized wherein the transdermal flux was found to be approximately 10 times more than the hydroethanolic solution. Also, the in-vivo pharmacodynamic study of the optimized ethosomal gel exhibited a higher percentage inhibition of swelling paw edema than marketed diclofenac gel.

CONCLUSION

The ethosomal gel was successfully developed and has shown the potential to be a good option for the replacement of conventional therapies of rheumatoid arthritis.

Factors affecting the morphology of some organic and inorganic nanostructures for drug delivery: characterization, modifications, and toxicological perspectives

Introduction: In this review, we aim to highlight the impact of various processes and formulation variables influencing the characteristics of certain surfactant-based nanoconstructs for drug delivery. Areas covered: The review includes the discussion on processing parameters for the preparation of nanoconstructs, especially those made up of surfactants. Articles published in last 15 years (437) were reviewed, 381 articles were selected for data review and most appropriate articles (215) were included in article. Effect of variables such as surfactant concentration and type, membrane additives, temperature, and pH-dependent transitions on morphology has been highlighted along with effect of shape on nanoparticle uptake by cells. Various characterization techniques explored for these nanostructures with respect to size, morphology, lamellarity, distribution, etc., and a separate section on polymeric vesicles and the influence of block copolymers, type of block copolymer, control of block length, interaction of multiple block copolymers on the structure of polymersomes and chimeric nanostructures have been discussed. Finally, applications, modification, degradation, and toxicological aspects of these drug delivery systems have been highlighted. Expert opinion: Parameters influencing the morphology of micelles and vesicles can directly or indirectly affect the efficacy of small molecule cellular internalization as well as uptake in the case of biologicals.[Figure: see text].

Innovative strategies to treat skin wounds with mangiferin: fabrication of transfersomes modified with glycols and mucin

Aim: The moisturizing properties of glycerol, the penetration enhancing capability of propylene glycol and the bioadhesive properties of mucin were combined to improve the carrier capabilities of transfersomes and the efficacy of mangiferin in the treatment of skin lesions. Materials & methods: Mangiferin was incorporated in transfersomes and glycoltransfersomes, which were also modified with mucin. The physico-chemical features were assessed, along with the efficacy against oxidative stress and skin wounds in vitro and in vivo. Results: Glycoltransfersomes promoted the deposition of mangiferin in epidermis and dermis, protected fibroblasts from oxidative stress and stimulated their proliferation. The wound healing and anti-inflammatory efficacy of glycoltransfersomes were confirmed in vivo. Conclusion: Results confirmed the potential of glycoltransfersomes in preventing/treating of skin lesions.

Topical photodynamic therapy of tumor bearing mice with meso-tetrakis (N-methyl-4-pyridyl) porphyrin loaded in ethosomes

Photodynamic therapy is a clinically approved procedure for the treatment of neoplastic and other non-malignant diseases. Meso-tetrakis(N-methyl-4-pyridyl)porphyrin (TMPyP) is a photosensitizing agent which has been used in many applications. However, the use of TMPyP topically is limited due to its hydrophilicity. To overcome this problem, TMPyP was loaded in ethosomes. Three ethosomal formulae (A), (B) and (C) were prepared and characterized. Preparation (A) was chosen to be used in the in vitro and in vivo study, having the greatest encapsulation efficiency, the smallest size and the highest cumulative release percentage. The results of in vitro permeation study revealed that the ethosomal TMPyP was superior to the drug in the free form with permeation flux (3.92 μg cm^-2 h^-1). In the in vivo animal study done on Swiss albino mice, after 19 days of Ehrlich tumor implantation, the group treated with the ethosomal preparation showed significantly smaller tumor size (143.28 ± 13.2 mm³) compared to the group treated with the free TMPyP (219 ± 11.9 mm³). It showed also significant longer survival time (21 days) compared to that treated with the free drug (18.2 ± 1.2 days). Based on the obtained results, transdermal delivery of TMPyP was potentiated by incorporating it in ethosomes.

Quality by design driven development of resveratrol loaded ethosomal hydrogel for improved dermatological benefits via enhanced skin permeation and retention

Resveratrol is a potent anti-oxidant agent and can be used for the effective management of different skin conditions like extrinsic skin ageing, psoriasis, etc. The objective of this research was to develop a dermal delivery system of resveratrol for its improved dermatological benefits for achieving its enhanced skin deposition profile with limited systemic exposure. Resveratrol loaded ethosomal hydrogel was developed and optimized using systematic Quality by Design approach. Firstly, the quality target product profile (QTPP) of ethosomal formulation was defined and critical quality attributes (CQAs) and critical material attributes (CMAs) were screened through risk assessment studies based on fish bone diagram. 3² full factorial design using Design Expert software was employed to optimize the selected CMAs. Concentration of phospholipid (X1) and concentration of ethanol (X2) were selected as independent CMAs. Vesicle size (Y1), entrapment efficiency (Y2), permeation flux (Y3) and drug deposition in dermal layer (Y4) were evaluated as dependant CQAs. Optimized formulation was then evaluated for physicochemical and skin permeation properties. Ethosomal hydrogel was able to significantly enhance the skin permeation parameters and skin deposition of resveratrol in comparison to the conventional cream. The results were highly ratified by CLSM studies in which ethosomal hydrogel was found to be vastly scattered in the deeper skin layers. Thus, there is evidence that systemically developed ethosomal gel can deliver enhanced amounts of bioactives into the skin and it is expected that a number of products for dermal/transdermal applications will be developed in the future based on it.

Antimicrobial Effect of Thymus capitatus and Citrus limon var. pompia as Raw Extracts and Nanovesicles

In view of the increasing interest in natural antimicrobial molecules, this study screened the ability of Thymus capitatus (TC) essential oil and Citrus limon var. pompia (CLP) extract as raw extracts or incorporated in vesicular nanocarriers against Streptococcus mutans and Candida albicans. After fingerprint, TC or CLP were mixed with lecithin and water to produce liposomes, or different ratios of water/glycerol or water/propylene glycol (PG) to produce glycerosomes and penetration enhancer vesicles (PEVs), respectively. Neither the raw extracts nor the nanovesicles showed cytotoxicity against human gingival fibroblasts at all the concentrations tested (1, 10, 100 μg/mL). The disc diffusion method, MIC-MBC/MFC, time-kill assay, and transmission electron microscopy (TEM) demonstrated the highest antimicrobial potential of TC against S. mutans and C. albicans. The very high presence of the phenol, carvacrol, in TC (90.1%) could explain the lethal effect against the yeast, killing up to 70% of Candida and not just arresting its growth. CLP, rich in polyphenols, acted in a similar way to TC in reducing S. mutans, while the data showed a fungistatic rather than a fungicidal activity. The phospholipid vesicles behaved similarly, suggesting that the transported extract was not the only factor to be considered in the outcomes, but also their components had an important role. Even if other investigations are necessary, TC and CLP incorporated in nanocarriers could be a promising and safe antimicrobial in caries prevention.

Optimization and Evaluation of Beclomethasone Dipropionate Micelles Incorporated into Biocompatible Hydrogel Using a Sub-Chronic Dermatitis Animal Model

The current study is concerned with the development and characterization of mixed micelles intended for the dermal delivery of beclomethasone dipropionate, which is a topical corticosteroid used in the management of atopic dermatitis. Mixed micelles were prepared using thin-film hydration technique, employing different concentrations of pluronic L121 with either poloxamer P84 or pluronic F127 with different surfactant mixture-to-drug ratios. The prepared formulae were characterized concerning entrapment efficiency, particle size, and zeta potential. Two formulae were chosen for ex vivo skin deposition studies: one formulated using pluronic L121/poloxamer P84 mixture while the other using pluronic L121/pluronic F127 mixture. The optimum formula with the highest dermal deposition was subjected to morphological examination and was formulated as hydroxypropyl methylcellulose hydrogel. The hydrogel was evaluated regarding viscosity and was subjected to ex vivo deposition study in comparison with the commercially available cream Beclozone®. In vivo histopathological study was conducted for both the hydrogel and Beclozone® in order to evaluate their healing efficiency. In vivo histopathological study results showed that the prepared hydrogel successfully treated sub-chronic dermatitis in an animal model within a shorter period of time compared to Beclozone®, resulting in better patient compliance and fewer side effects.

Solutol HS15 based binary mixed micelles with penetration enhancers for augmented corneal delivery of sertaconazole nitrate: optimization, in vitro, ex vivo and in vivo characterization

Keratomycosis is a serious corneal disease that can cause a permanent visual disability if not treated effectively. Sertaconazole nitrate (STZ), a novel broad spectrum antifungal drug, was suggested as a promising treatment. However, its utility in the ocular route is restricted by its poor solubility, along with other problems facing the ocular delivery like short residence time, and the existing corneal barrier. Therefore, the objective of this study was to formulate STZ loaded binary mixed micelles (STZ-MMs) enriched with different penetration enhancers using thin-film hydration method, based on a 3¹.2² mixed factorial design. Different formulation variables were examined, namely, type of auxiliary surfactant, type of penetration enhancer, and total surfactants: drug ratio, and their effects on the solubility of STZ in MMs (S_M), particle size (PS), polydispersity index (PDI), and zeta potential (ZP) were evaluated. STZ-MMs enhanced STZ aqueous solubility up to 338.82-fold compared to free STZ. Two optimized formulations (MM-8 and MM-11) based on the desirability factor (0.891 and 0.866) were selected by Design expert^® software for further investigations. The optimized formulations were imaged by TEM which revealed nanosized spherical micelles. Moreover, they were examined for corneal mucoadhesion, stability upon dilution, storage effect, and ex vivo corneal permeation studies. Finally, both in vivo corneal uptake and in vivo corneal tolerance were investigated. MM-8 showed superiority in the ex vivo and in vivo permeation studies when compared to the STZ-suspension. The obtained results suggest that the aforementioned STZ loaded mixed micellar system could be an effective candidate for Keratomycosis-targeted therapy.

Liposomes with an Ethanol Fraction as an Application for Drug Delivery

Liposomes containing a certain amount of ethanol are often referred to in the literature as ethosomes. Liposomes vary in size from 25 nm to 25,000 nm. Ethosomes are defined as lipids composed of phospholipids, ethanol, or isopropyl alcohol in quite high concentrations, and water. They enable active substances to reach the deep skin layers or even the general circulation. The structure of ethosomes allows for an increased penetration of the drug through two effects: the ethanolic effect and the ethosomal effect. Ethosomes can be obtained using three methods: the hot method, the cold method, and the classic method of mechanical dispersion. The literature describes many of the therapeutic groups of drugs that can be enclosed in ethosomal formulations. These include anti-viral drugs, antineoplastic drugs, antifungal drugs, hypnotic drugs, hormones, and many others. Ethosomes show important practical advantages compared to classic liposomes. It is necessary to conduct research with regard to real pharmaceutical systems using advanced physicochemical techniques.

A novel ultradeformable liposomes of Naringin for anti-inflammatory therapy

Ultradeformable liposomes were formulated using naringin (NA), a flavanone glycoside, at different concentrations (3, 6 and 9mg/mL). Nanovesicles were small size (∼100nm), regardless of the NA concentration used, and monodisperse (PI<0.30). All formulations showed a high entrapment efficiency (∼88%) and a highly negative zeta potential (around -30mV). The selected formulations were highly biocompatible as confirmed by in vitro studies using 3T3 fibroblasts. In vitro assay showed that the amounts (%) of NA accumulated in the epidermis (∼10%) could explain the anti-inflammatory properties of ultradeformable liposomes. In vivo studies confirmed the higher effectiveness of ultradeformable liposomes respect to betamethasone cream and NA dispersion in reducing skin inflammation in mice. Overall, it can conclude that NA ultradeformable liposomes can be considered as a promising formulation for the treatment of skin inflammatory diseases.

Development and evaluation of finasteride loaded ethosomes for targeting to the pilosebaceous unit

Androgenetic alopecia, a major cause for baldness, is caused by the deposition of dihydrotestosterone (DHT) at the androgen receptors present in the pilosebaceous unit (PSU). Finasteride (FIN) is a potent 5α-reductase inhibitor capable of preventing the conversion of testosterone to DHT. But, its oral administration in males causes infertility. An attempt was made to prepare ethosomes of FIN with a size range 100-300 nm to enhance its delivery to the PSU. Finasteride loaded ethosomes (FES) were prepared using an ultra-probe sonicator and characterized for its size, morphology, surface charge and entrapment efficiency. The ability of FES to permeate across rat skin and frontal scalp skin of human cadaver was also evaluated. The spherical shaped ethosomes of different batches were in the size range of 107.8 ± 2.50 to 220.4 ± 6.92 nm and showed good permeation across rat skin and frontal scalp skin of human cadaver when compared to the unencapsulated FIN. The results portrayed the ability of FES to permeate across the stratum corneum to reach the PSU of the hair follicle. Although additional use of permeation enhancer increases the permeation of FIN across the skin, its addition may not be a favourable option for the deposition of ethosomes in the PSU.

Effect of quercetin and resveratrol co-incorporated in liposomes against inflammatory/oxidative response associated with skin cancer

The present investigation reports the development of liposomes for the co-delivery of naturally occurring polyphenols, namely quercetin and resveratrol. Small, spherical, uni/bilamellar vesicles were produced, as demonstrated by light scattering, cryo-TEM, SAXS. The incorporation of quercetin and resveratrol in liposomes did not affect their intrinsic antioxidant activity, as DPPH radical was almost completely inhibited. The cellular uptake of the polyphenols was higher when they were formulated in liposomes, and especially when co-loaded rather than as single agents, which resulted in a superior ability to scavenge ROS in fibroblasts. The in vivo efficacy of the polyphenols in liposomes was assessed in a mouse model of skin lesion. The topical administration of liposomes led to a remarkable amelioration of the tissue damage, with a significant reduction of oedema and leukocyte infiltration. Therefore, the proposed approach based on polyphenol vesicular formulation may be of value in the treatment of inflammation/oxidative stress associated with pre-cancerous/cancerous skin lesions.

Inhibition of skin inflammation by baicalin ultradeformable vesicles

The topical efficacy of baicalin, a natural flavonoid isolated from Scutellaria baicalensis Georgi, which has several beneficial properties, such as antioxidative, antiviral, anti-inflammatory and antiproliferative, is hindered by its poor aqueous solubility and low skin permeability. Therefore, its incorporation into appropriate phospholipid vesicles could be a useful tool to improve its local activity. To this purpose, baicalin at increasing concentrations up to saturation, was incorporated in ultradeformable vesicles, which were small in size (∼67nm), monodispersed (PI<0.19) and biocompatible, regardless of the concentration of baicalin, as confirmed by in vitro studies using fibroblasts. On the other hand, transdermal flux through human epidermis was concentration dependent. The in vivo results showed the significant anti-inflammatory activity of baicalin loaded nanovesicles irrespective of the concentration used, as they were able to reduce the skin damage induced by the phorbol ester (TPA) application, even in comparison with dexamethasone, a synthetic drug with anti-inflammatory properties. Overall results indicate that ultradeformable vesicles are promising nanosystems for the improvement of cutaneous delivery of baicalin in the treatment of skin inflammation.

Ethosomal nanocarriers: the impact of constituents and formulation techniques on ethosomal properties, in vivo studies, and clinical trials

Ethosomal systems are novel lipid vesicular carriers containing a relatively high percentage of ethanol. These nanocarriers are especially designed for the efficient delivery of therapeutic agents with different physicochemical properties into deep skin layers and across the skin. Ethosomes have undergone extensive research since they were invented in 1996; new compounds were added to their initial formula, which led to the production of new types of ethosomal systems. Different preparation techniques are used in the preparation of these novel carriers. For ease of application and stability, ethosomal dispersions are incorporated into gels, patches, and creams. Highly diverse in vivo models are used to evaluate their efficacy in dermal/transdermal delivery, in addition to clinical trials. This article provides a detailed review of the ethosomal systems and categorizes them on the basis of their constituents to classical ethosomes, binary ethosomes, and transethosomes. The differences among these systems are discussed from several perspectives, including the formulation, size, ζ-potential (zeta potential), entrapment efficiency, skin-permeation properties, and stability. This paper gives a detailed review on the effects of ethosomal system constituents, preparation methods, and their significant roles in determining the final properties of these nanocarriers. Furthermore, the novel pharmaceutical dosage forms of ethosomal gels, patches, and creams are highlighted. The article also provides detailed information regarding the in vivo studies and clinical trials conducted for the evaluation of these vesicular systems.

Diclofenac acid nanocrystals as an effective strategy to reduce in vivo skin inflammation by improving dermal drug bioavailability

In this work a diclofenac acid nanosuspension formulation was produced as a novel approach for the treatment of skin inflammation. Drug nanocrystals, prepared by the wet media milling technique and stabilized using Poloxamer 188, were characterized by different techniques: scanning electron microscopy, differential scanning calorimetry, X-ray powder diffractometry, Fourier transform infrared spectroscopy and photon correlation spectroscopy. The ability of nanocrystals to improve dermal drug bioavailability was investigated ex vivo by using Franz diffusion vertical cells and mouse skin, in comparison with both diclofenac acid coarse suspensions and a commercial formulation. The topical anti-inflammatory activity of the drug nanosuspension was assessed in vivo by testing its effect compared to common inflammatory endpoints: i.e. the inhibition of chemically induced oedema and leucocyte infiltration (reflected in myeloperoxidase activity). Following the milling procedure, diclofenac nanocrystals exhibited a mean diameter of approximately 279nm, a low polydispersity index (∼0.17) and maintained the same polymorphic form of the starting bulk powder. When the drug nanosuspension was applied on the mouse skin it produced a higher accumulation of diclofenac in the skin compared to both the coarse suspensions and the commercial formulation, as demonstrated by ex vivo transdermal delivery experiments. Moreover, the nanosuspension provided an in vivo oedema inhibition of 50%, which was not statistically different from the commercial formulation. On the contrary, the nanosuspension showed a higher inhibition of myeloperoxidase activity in the damaged tissue (86%) than the commercial formulation (16%).

Statistical optimization of tretinoin-loaded penetration-enhancer vesicles (PEV) for topical delivery

Background

The aim of this study was to develop and optimize deformable liposome for topical delivery of tretinoin.

Methods

Liposomal formulations were designed based on the full factorial design and prepared by fusion method. The influence of different ratio of soy phosphatidylcholine and transcutol (independent variables) on incorporation efficiency and drug release in 15 min and 24 h (responses) from liposomal formulations was evaluated. Liposomes were characterized for their vesicle size and Differential Scanning Calorimetry (DSC) was used to investigate changes in their thermal behavior. The penetration and retention of drug was determined using mouse skin. Also skin histology study was performed.

Results

Particle size of all formulations was smaller than 20 nm. Incorporation efficiency of liposomes was 79–93 %. Formulation F7 (25:5) showed maximum drug release. Optimum formulations were selected based on the contour plots resulted by statistical equations of drug release in 15 min and 24 h. Solubility properties of transcutol led to higher skin penetration for optimum formulations compared to tretinoin cream. There was no significant difference between the amount of drug retained in the skin by applying optimum formulations and cream. Histopatological investigation suggested optimum formulations could decrease the adverse effect of tretinoin in liposome compared to conventional cream.

Conclusion

According to the results of the study, it is concluded that deformable liposome containing transcutol may be successfully used for dermal delivery of tretinoin.

Photostability and ex-vivo permeation studies on diclofenac in topical niosomal formulations

Photostability studies were performed on topical formulations containing diclofenac (DC). Niosomal gels were designed as photostabilization systems and ascorbic acid was also added to the new topical formulations because of its antioxidant property. Photodegradation tests were applied on commercial formulations containing DC and novel prepared gels, according to the ICH rules. The experiments were monitored by spectrophotometry and the data processed by multivariate curve resolution analysis to estimate the spectra and concentration profiles of evolved components. Characterization of niosomes was evaluated by size and distribution measurement, morphological analysis and encapsulation efficiency. Permeation experiments were performed across rabbit ear skin up to 24 h. Photodegradation rate of DC was found very fast in commercial formulation, with a residual content of 90% after only 4.38 min under a radiant exposure of 450 W/m(2). Photostability resulted increased significantly when the drug was entrapped in niosomal systems. The best results were obtained by reaching a 10% degradation after 50.00 min of light exposure after incorporation of DC in niosomes in presence of 5% ascorbic acid. Moreover, niosomal gel also influenced the permeation capability of DC by enhancing the transdermal delivery of the drug. The cumulative dose permeated of DC from niosomal gel was about three times that obtained with the commercial gel.

Nanocarriers in therapy of infectious and inflammatory diseases

Nanotechnology is a growing science that has applications in various areas of medicine. The composition of nanocarriers for drug delivery is critical to guarantee high therapeutic performance when targeting specific host sites. Applications of nanotechnology are prevalent in the diagnosis and treatment of infectious and inflammatory diseases. This review summarizes recent advancements in the application of nanotechnology to the therapy of infectious and inflammatory diseases. The major focus is on the design and fabrication of various nanomaterials, characteristics and physicochemical properties of drug-loaded nanocarriers, and the use of these nanoscale drug delivery systems in treating infectious and inflammatory diseases, such as AIDS, hepatitis, tuberculosis, melanoma, and representative inflammatory diseases. Clinical trials and future perspective of the use of nanocarriers are also discussed in detail. We hope that such a review will be valuable to researchers who are exploring nanoscale drug delivery systems for the treatment of specific infectious and inflammatory diseases.

Therapeutic efficacy of quercetin enzyme-responsive nanovesicles for the treatment of experimental colitis in rats

Biocompatible quercetin nanovesicles were developed by coating polyethylene glycol-containing vesicles with chitosan and nutriose, aimed at targeting the colon. Uncoated and coated vesicles were prepared using hydrogenated soy phosphatidylcholine and quercetin, a potent natural anti-inflammatory and antioxidant drug. Physicochemical characterization was carried out by light scattering, cryogenic microscopy and X-ray scattering, the results showing that vesicles were predominantly multilamellar and around 130 nm in size. The in vitro release of quercetin was investigated under different pH conditions simulating the environment of the gastrointestinal tract, and confirmed that the chitosan/nutriose coating improved the gastric resistance of vesicles, making them a potential carrier system for colon delivery. The preferential localization of fluorescent vesicles in the intestine was demonstrated using the In Vivo FX PRO Imaging System. Above all, a marked amelioration of symptoms of 2,4,6-trinitrobenzenesulfonic acid-induced colitis was observed in animals treated with quercetin-loaded coated vesicles, favoring the restoration of physiological conditions. Therefore, quercetin-loaded chitosan/nutriose-coated vesicles can represent a valuable therapeutic tool for the treatment of chronic intestinal inflammatory diseases, and presumably a preventive system, due to the synergic action of antioxidant quercetin and beneficial prebiotic effects of the chitosan/nutriose complex.

Identification and nanoentrapment of polyphenolic phytocomplex from Fraxinus angustifolia: in vitro and in vivo wound healing potential

The aim of the present study was to elucidate the polyphenolic composition of Fraxinus angustifolia leaf and bark extracts, and to evaluate their efficacy in wound healing. Quercetin, catechin, rutin and tannic acid were identified as the main components of the extracts. In order to improve their skin bioavailability, the polyphenolic phytocomplexes were incorporated in different nanovesicles, namely ethosomes and phospholipid vesicles containing Transcutol(®) P (Trc) or ethylene glycol (EG). The latter had never been used before as a component of phospholipid vesicles, and it was found to play a key role in improving extract efficacy in wound healing. Results of cryogenic transmission electron microscopy (cryo-TEM), Photon Correlation Spectroscopy (PCS) and Small-Angle X-ray Scattering (SAXS) showed that ethosomes and EG-PEVs were small, monodispersed, unilamellar vesicles, while Trc-PEVs were larger, less homogeneously dispersed and multilamellar, with a large bilayer thickness. Free extracts did not show relevant ability to protect in vitro human keratinocytes from H2O2 damages, while when entrapped in nanovesicles, they significantly inhibited H2O2 stress damages, probably related to a higher level of cell uptake. On the other hand, in vivo results showed that the highest antioxidant and anti-inflammatory effects were provided by the phytocomplexes in EG-PEVs, which favoured wound healing. Moreover, non-entrapped F. angustifolia extracts showed a marginal effect, comparable to that of free quercetin dispersion (control). In conclusion, our results depict that these extracts may find potential applications in biomedicine.

Nanomedicine strategies for targeting skin inflammation

Topical treatment of skin diseases is an attractive strategy as it receives high acceptance from patients, resulting in higher compliance and therapeutic outcomes. Recently, the use of variable nanocarriers for dermal application has been widely explored, as they offer several advantages compared with conventional topical preparations, including higher skin penetration, controlled and targeted drug delivery and the achievement of higher therapeutic effects. This article will focus on skin inflammation or dermatitis as it is one of the most common skin problems, describing the different types and causes of dermatitis, as well as the typical treatment regimens. The potential use of nanocarriers for targeting skin inflammation and the achievement of higher therapeutic effects using nanotechnology will be explored.

Fabrication of quercetin and curcumin bionanovesicles for the prevention and rapid regeneration of full-thickness skin defects on mice

In the present work biocompatible quercetin and curcumin nanovesicles were developed as a novel approach to prevent and restore skin tissue defects on chronic cutaneous pathologies. Stable and suitable quercetin- and curcumin-loaded phospholipid vesicles, namely liposomes and penetration enhancer-containing vesicles (PEVs), were prepared. Vesicles were made from a highly biocompatible mixture of phospholipids and alternatively a natural polyphenol, quercetin or curcumin. Liposomes were obtained by adding water, while PEVs by adding polyethylene glycol 400 and Oramix®CG110 to the water phase. Transmission electron microscopy, cryogenic-transmission electron microscopy and small- and wide-angle X-ray scattering showed that vesicles were spherical, oligo- or multilamellar and small in size (112-220 nm). In vitro and in vivo tests underlined a good effectiveness of quercetin and curcumin nanovesicles in counteracting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) induced lesions and inflammation. Myeloperoxydase activity, used to gauge inflammation, was markedly inhibited by quercetin liposomes (59%) and curcumin liposomes and polyethylene glycol (PEG)-PEVs (∼ 68%). Histology showed that PEG-PEVs provided an extensive re-epithelization of the TPA-damaged skin, with multiple layers of thick epidermis. In conclusion, nanoentrapped polyphenols prevented the formation of skin lesions abrogating the various biochemical processes that cause epithelial loss and skin damage.

Topical anti-inflammatory potential of quercetin in lipid-based nanosystems: in vivo and in vitro evaluation

PURPOSE

To develop quercetin-loaded phospholipid vesicles, namely liposomes and PEVs (Penetration Enhancer-containing Vesicles), and to investigate their efficacy on TPA-induced skin inflammation.

METHODS

Vesicles were made from a mixture of phospholipids, quercetin and polyethylene glycol 400 (PEG), specifically added to increase drug solubility and penetration through the skin. Vesicle morphology and self-assembly were probed by Cryo-Transmission Electron Microscopy and Small/Wide Angle X-ray Scattering, as well as the main physico-chemical features by Light Scattering. The anti-inflammatory efficacy of quercetin nanovesicles was assessed in vivo on TPA-treated mice dorsal skin by the determination of two biomarkers: oedema formation and myeloperoxidase activity. The uptake of vesicles by 3T3 fibroblasts was also evaluated.

RESULTS

Small spherical vesicles were produced. Their size and lamellarity was strongly influenced by the PEG content (0%, 5%, 10% v/v). The administration of vesicular quercetin on TPA-inflamed skin resulted in an amelioration of the tissue damage, with a noticeable attenuation of oedema and leukocyte infiltration, especially using 5% PEG-PEVs, as also confirmed by confocal microscopy. In vitro studies disclosed a massive uptake and diffusion of PEVs in dermal fibroblasts.

CONCLUSIONS

The proposed approach based on quercetin vesicular formulations may be of value in the treatment of inflammatory skin disorders.

Highly deformable and highly fluid vesicles as potential drug delivery systems: theoretical and practical considerations

Vesicles that are specifically designed to overcome the stratum corneum barrier in intact skin provide an efficient transdermal (systemic or local) drug delivery system. They can be classified into two main groups according to the mechanisms underlying their skin interaction. The first group comprises those possessing highly deformable bilayers, achieved by incorporating edge activators to the bilayers or by mixing with certain hydrophilic solutes. The vesicles of this group act as drug carriers that penetrate across hydrophilic pathways of the intact skin. The second group comprises those possessing highly fluid bilayers, owing to the presence of permeation enhancers. The vesicles of this group can act as carriers of drugs that permeate the skin after the barrier of the stratum corneum is altered because of synergistic action with the permeation enhancers contained in the vesicle structure. We have included a detailed overview of the different mechanisms of skin interaction and discussed the most promising preclinical applications of the last five years of Transfersomes® (IDEA AG, Munich, Germany), ethosomes, and invasomes as carriers of antitumoral and anti-inflammatory drugs applied by the topical route.

Recent expansions in an emergent novel drug delivery technology: Emulgel

Emulgel is an emerging topical drug delivery system to which if more effort is paid towards its formulation & development with more number of topically effective drugs it will prove a boon for derma care & cosmetology. Emulgels are either emulsion of oil in water or water in oil type, which is gelled by mixing it with gelling agent. Incorporation of emulsion into gel increases its stability & makes it a dual control release system. Due to lack of excess oily bases & insoluble excipients, it shows better drug release as compared to other topical drug delivery system. Presence of gel phase makes it a non greasy & favors good patient compliance. These reviews give knowledge about Emulgel including its properties, advantages, formulation considerations, and its recent advances in research field. All factors such as selection of gelling agent, oil agent, emulsifiers influencing the stability and efficacy of Emulgel are discussed. All justifications are described in accordance with the research work carried out by various scientists. These brief reviews on formulation method have been included. Current research works that carried out on Emulgel are also discussed and highlighted the wide utility of Emulgel in topical drug delivery system. After the vast study, it can be concluded that the Emulgels appear better & effective drug delivery system as compared to other topical drug delivery system. The comprehensive analysis of rheological and release properties will provide an insight into the potential usage of Emulgel formulation as drug delivery system.