Improved efficacy in the treatment of contact dermatitis in rats by a dermatological nanomedicine containing clobetasol propionate

Tackling myelin deficits in neurodevelopmental disorders using drug delivery systems

Interest in myelin and its roles in almost all brain functions has been greatly increasing in recent years, leading to countless new studies on myelination, as a dominant process in the development of cognitive functions. Here, we explore the unique role myelin plays in the central nervous system and specifically discuss the results of altered myelination in neurodevelopmental disorders. We present parallel developmental trajectories involving myelination that correlate with the onset of cognitive impairment in neurodevelopmental disorders and discuss the key challenges in the treatment of these chronic disorders. Recent developments in drug repurposing and nano/micro particle-based therapies are reviewed as a possible pathway to circumvent some of the main hurdles associated with early intervention, including patient's adherence and compliance, side effects, relapse, and faster route to possible treatment of these disorders. The strategy of drug encapsulation overcomes drug solubility and metabolism, with the possibility of drug targeting to a specific compartment, reducing side effects upon systemic administration.

Bioadhesive 3D-Printed Skin Drug Delivery Polymeric Films: From the Drug Loading in Mesoporous Silica to the Manufacturing Process

The alliance between 3D printing and nanomaterials brings versatile properties to pharmaceuticals, but few studies have explored this approach in the development of skin delivery formulations. In this study, clobetasol propionate (CP) was loaded (about 25% w/w) in mesoporous silica nanomaterial (MSN) to formulate novel bioadhesive and hydrophilic skin delivery films composed of pectin (5% w/v) and carboxymethylcellulose (5% w/v) by 3D printing. As a hydrophobic model drug, CP was encapsulated in MSN at a 3:1 (w/w) ratio, resulting in a decrease of CP crystallinity and an increase of its dissolution efficiency after 72 h (65.70 ± 6.52%) as compared to CP dispersion (40.79 ± 4.75%), explained by its partial change to an amorphous form. The CP-loaded MSN was incorporated in an innovative hydrophilic 3D-printable ink composed of carboxymethylcellulose and pectin (1:1, w/w), which showed high tensile strength (3.613 ± 0.38 N, a homogenous drug dose (0.48 ± 0.032 mg/g per film) and complete CP release after 10 h. Moreover, the presence of pectin in the ink increased the skin adhesion of the films (work of adhesion of 782 ± 105 mN·mm). Therefore, the alliance between MSN and the novel printable ink composed of carboxymethylcellulose and pectin represents a new platform for the production of 3D-printed bioadhesive films, opening a new era in the development of skin delivery systems.

Development of a nanotechnological hydrogel containing desonide nanocapsules in association with acai oil: design and in vivo evaluation

Nanotechnological products have been used as strategies to optimize the therapy and minimize the side effects of topical corticoids. The objective of this study was to develop hydrogels by the addition of sclerotium gum to the suspensions of desonide-loaded açai oil-based nanocapsules and to study their biological effect using an animal model of acute skin inflammation. The hydrogels presented a pH compatible with topical application (4.4 to 5.0), nanometric mean diameter (131 to 165 nm), pseudoplastic behavior, and stability under room conditions during 30 days. The in vitro skin permeation/penetration study demonstrated that a higher amount of desonide (p < 0.05) was retained in the epidermis from the nanotechnological-hydrogels (0.33 to 0.36 µg.cm²) in comparison to the commercial gel cream (0.16 µg.cm²). In the dermis, the nanostructured hydrogels promoted a lower DES retention compared to the non-nanostructured formulations (p < 0.05). This result may indicate a smaller amount of drug reaching the bloodstream and, thus, fewer side effects can be expected. Concerning the anti-inflammatory effect, the developed hydrogels reduced both ear edema and inflammatory cell infiltration, showing an effect comparable to the commercially available formulation, which presents twice the drug concentration. The hydrogels developed may be considered a promising approach to treat dermatological disorders.

Novel Dermal Delivery Cargos of Clobetasol Propionate: An Update

Dermal disorders such as psoriasis and eczema are associated with modifications in the chemical and molecular composition of the skin. Clobetasol propionate (CP), a superpotent topical glucocorticoid, is widely used for the therapeutic management of various skin conditions, owing to its strong anti-inflammatory, antipruritic, vasoconstrictive, and antiproliferative activities. Safety studies demonstrated that CP is safer for a shorter period, however, with prolonged application, it shows secondary side effects such as photosensitivity, Cushing-like syndrome, allergic contact dermatitis, osteonecrosis, hypopigmentation, steroid acne, and skin atrophy. Therefore, the US FDA (United States Food and Drug Administration) has restricted the usage of CP to not more than 15 days. Research scientists addressed its several formulations and drug delivery issues, such as low water solubility, less stability, photodegradation, and poor absorption, by incorporating them into novel nanobased delivery platforms. With the utilization of these technologies, these drawbacks of CP have been resolved to a large extent to reestablish this moiety. This article explores the physicochemical properties and mechanism of action of CP. Additionally, an attempt has been made to discover and highlight the possible features of the novel nanosystems, including nanoemulsions, nanosponges, solid lipid nanoparticles, nanostructured lipid carriers, and nanogels, reported for CP. The stability and safety concerns of CP, along with its commercial status, are also discussed.

Ligand Decorated Primaquine Loaded Nanocarriers for Liver Targeting for Triggered Anti-Malarial Activity

OBJECTIVE

The aim of the current research is to formulate a nano delivery system for effective delivery of primaquine for liver targeting to achieve the potential anti-malarial activity. Another objective of current development is to formulate a lactobionic acid conjugated polyphosphazene based nano delivery of primaquine for liver targeting to distinguish anti-malarial activity.

METHOD

The particle size, entrapment efficiency, in-vitro drug release pattern, hepatotoxicity, MTT assay, erythrocyte toxicity assay, histopathology study, HepG2 cell uptake study, anti-- malarial study, and organ-distribution was also carried out to estimate the activity and potential features of a nanoparticle system.

RESULTS

The results obtained from the above analysis justify the efficiency and effectiveness of the system. The NMR studies confirm the conjugation pattern and the TEM represents the spherical morphological features of nanoparticles. The controlled release pattern from the in-vitro release study was observed and found to be 73.25% of drug release in 20 hrs and in the nano-size range (61.6± 1.56 nm) by particle size analysis.SGOT level, SGPT, ALP, and Parasitemia level of optimized drug-loaded PEGylated lactobionic acid conjugated polyphosphazene derivatized nanoparticles (FF) was found to lie in the safe range, showing that the formulation is non-toxic to the liver. Primaquine drug-loaded PEGylated lactobionic acid conjugated polyphosphazene polymeric nanoparticles showed higher cell uptake on HepG2 cell lines as compared to the drug-loaded in PEGylated polyphosphazene polymeric nanoparticles and plain drug.Percentage cell viability of drugloaded PEGylated lactobionic acid conjugated polyphosphazene derivatized nanoparticles was decreased by enhancing the concentration of prepared nanoparticle system accessed by MTT assay.

CONCLUSION

From the studies, it can be concluded that the optimized formulation of drug-loaded PEGylated lactobionic acid conjugated polyphosphazene derivatized nanoparticles showed high liver targeting, least toxicity to the liver, controlled release of the drug, higher anti-malarial activity against hepatocytes at a low dose, more effectiveness, and can be treated as a potential candidate for anti-malarial therapy.

Nano intervention in topical delivery of corticosteroid for psoriasis and atopic dermatitis-a systematic review

Atopic dermatitis (AD) and psoriasis are highly prevalent, complex, chronic inflammatory skin diseases that immensly affect the patient's quality of life. While there is no definitive cure for these conditions, suppressive medications aim at managing the symptoms of these diseases. The application of emollients accompanied by symptomatic anti-inflammatory therapy consisting of topical corticosteroids (TCS) is extensively employed for controlling the symptoms among general practitioners making this therapeutic class an indispensable pillar of dermatotherapeutics. The first TCS, hydrocortisone (HC) introduced in the early 1950s led to the development of different steroidal moieties of varying potencies by inducing chemical modifications to the basic steroid structure. The wide spectrum of the available range of formulations and potency provides flexibility to treat all patient groups, different phases of the diseases, and different anatomical sites. Conventional TCS therapy suffers from drawbacks such as low drug permeation and retention rate. Thus, novel nanoformulations have been developed to overcome these problems. This review provides an insight into the current state of nanocarrier-mediated topical delivery of corticosteroids monotherapy and combination therapy with special emphasis on targeting psoriasis and AD.

Dermatopharmacokinetic and pharmacodynamic evaluation of a novel nanostructured formulation containing capsaicinoids for treating neuropathic pain

The in vivo skin penetration by dermal microdialysis and the pharmacological efficacy of a chitosan hydrogel containing capsaicinoids-loaded nanocapsules (CHNC_Caps) was evaluated in this study. Such gel has previously been proven to control capsaicinoids release and decrease the drugs side effects in humans. The nanocapsules containing capsaicinoids had an average size around 150 nm, with a low polydispersity index, positive zeta potential, and high encapsulation efficiency of the drugs. The CHNC_Caps showed intact nanocapsules, a slightly acid pH value, and a pseudoplastic behavior suitable for topical application. Microdialysis experiments showed a 1.6-fold increase in the concentration of capsaicinoids in the dermis (after 12 h of its application) when CHNC_Caps was administered compared to a chitosan hydrogel containing capsaicinoids in hydroethanolic solution (CHET_Caps) and the commercial cream. The CHNC_Caps showed antiallodynic and antihyperalgesic effects from 6 h to 96 h after treatment initiation, whereas CHET_Caps and the commercial cream showed antiallodynic and antihyperalgesic effects only at 48 h and 96 h after treatment initiation, respectively. CHNC_Caps and the commercial cream maintained antihyperalgesic activity for 6 days after treatment interruption. For mechanical allodynia, the antinociceptive effect was maintained for 48 h after treatment interruption only with CHNC_Caps. In conclusion, CHNC_Caps is a promising formulation for treating peripheral neuropathic pain.

Tackling the various classes of nano-therapeutics employed in topical therapy of psoriasis

Psoriasis is a dermatological chronic skin condition with underlying autoimmune etiology. It deeply affects patients' quality of life. Therefore, it was an interesting target for researchers throughout the past years. Conventionally, the treatment options include anti-inflammatory agents, immune suppressants, biologic treatment, and phototherapy. Nanotechnology offers promising characteristics that allow for tailoring a drug carrier to achieve dermal targeting, improved efficacy and minimize undesirable effects. Being the safest route, the first line of treatment and a targeted approach, we solely discussed the use of the topical route, combined with advanced drug delivery systems for the management of psoriasis in this article. Advanced systems include polymeric, metallic, lipidic and hybrid nanocarriers incorporating different active agents. All formerly mentioned types of drug delivery systems were investigated through the past decades for the purpose of topical application on psoriatic plaques. Scientists' efforts are promising to reach an optimized formula with a convenient dosage form to improve efficacy, safety, and compliance for the treatment of psoriasis. Accordingly, it will offer a better quality of life for patients.

Topical delivery of clobetasol propionate loaded nanosponge hydrogel for effective treatment of psoriasis: Formulation, physicochemical characterization, antipsoriatic potential and biochemical estimation

Clobetasol propionate (CP), a superpotent topical corticosteroid, holds great promise for psoriasis treatment. However, common side effects like skin atrophy, steroidal acne, hypopigmentation and allergic contact dermatitis associated with it, hamper its utility for topical application. Taking this into consideration, the current work was aimed to fabricate CP loaded cyclodextrin nanosponge (CDNS) based hydrogel, to alleviate the aforementioned side effects, while controlling drug release. Nanosponges were crafted employing β-cyclodextrin (polymer) and diphenyl carbonate (cross linker) and evaluated appropriately. The selected formulation augmented 45 folds water solubility, with respect to pure CP. The formulation possessed entrapment efficiency (56.33 ± 0.94%), particle size (194.27 ± 49.24 nm) with polydispersitive index (0.498 ± 0.095), surface charge (-21.83 ± 0.95 mV) and drug release (86.25 ± 0.28%). Selected CP-CDNS were found crystalline and uniform in size. Further, in vitro cell viability analysis has been performed using THP1 cells to evaluate cytocompatibility of CP nanosponges. The chosen CP nanosponges were then embedded into Carbopol hydrogel, and characterized for rheological behaviour, spreadability, and texture profile. The developed nanoformulations were also assessed in vivo using mouse tail model. Histological and biochemical assessments have been conducted to explore their antipsoriatic activity via oxidative stress biomarkers. The degree of orthokeratosis was observed remarkably (p < 0.001) amplified by CP-CDNS14 hydrogel as compared to untreated group (control) and CP hydrogel. In addition, drug activity and change in epidermal thickness were found significant. Our findings altogether advocated the profound potential of prepared CP nanogel in the topical treatment of psoriasis, with improved patient compliance.

Non-invasive drug delivery technology: development and current status of transdermal drug delivery devices, techniques and biomedical applications

Pay-load deliveries across the skin barrier to the systemic circulation have been one of the most challenging delivery options. Necessitated requirements of the skin and facilitated skin layer cross-over delivery attempts have resulted in development of different non-invasive, non-oral methods, devices and systems which have been standardized, concurrently used and are in continuous upgrade and improvements. Iontophoresis, electroporation, sonophoresis, magnetophoresis, dermal patches, nanocarriers, needled and needle-less shots, and injectors are among some of the methods of transdermal delivery. The current review covers the current state of the art, merits and shortcomings of the systems, devices and transdermal delivery patches, including drugs' and other payloads' passage facilitation techniques, permeation and absorption feasibility studies, as well as physicochemical properties affecting the delivery through different transdermal modes along with examples of drugs, vaccines, genes and other payloads.

Co-Delivery of Imiquimod and Curcumin by Nanoemugel for Improved Topical Delivery and Reduced Psoriasis-Like Skin Lesions

The current investigation aimed to improve the topical efficacy of imiquimod in combination with curcumin using the nanoemulsion-based delivery system through a combinatorial approach. Co-delivery of curcumin acts as an adjuvant therapeutic and to minimize the adverse skin reactions that are frequently associated with the topical therapy of imiquimod for the treatment of cutaneous infections and basal cell carcinomas. The low-energy emulsification method was used for the nano-encapsulation of imiquimod and curcumin in the nanodroplet oil phase, which was stabilized using Tween 20 in an aqueous dispersion system. The weak base property of imiquimod helped to increase its solubility in oleic acid compared with ethyl oleate, which indicates that fatty acids should be preferred as the oil phase for the design of imiquimod-loaded topical nanoemulsion compared with fatty acid esters. The phase diagram method was used to optimize the percentage composition of the nanoemulsion formulation. The mean droplet size of the optimized nanoemulsion was 76.93 nm, with a polydispersity index (PdI) value of 0.121 and zeta potential value of −20.5 mV. The optimized imiquimod-loaded nanoemulsion was uniformly dispersed in carbopol 934 hydrogel to develop into a nanoemulgel delivery system. The imiquimod nanoemulgel exhibited significant improvement (p < 0.05) in skin permeability and deposition profile after topical application. The in vivo effectiveness of the combination of imiquimod and curcumin nanoemulgel was compared to the imiquimod nanoemulgel and imiquimod gel formulation through topical application for ten days in BALB/c mice. The combination of curcumin with imiquimod in the nanoemulgel system prevented the appearance of psoriasis-like symptoms compared with the imiquimod nanoemulgel and imiquimod gel formulation entirely. Further, the imiquimod nanoemulgel as a mono-preparation slowed and reduced the psoriasis-like skin reaction when compared with the conventional imiquimod gel, and that was contributed to by the control release property of the nano-encapsulation approach.

New pectin-based hydrogel containing imiquimod-loaded polymeric nanocapsules for melanoma treatment

We developed a pectin-based hydrogel containing nanocapsules as a new strategy for melanoma treatment. Our first objective was to evaluate the nanoencapsulation effect of imiquimod on melanoma. Imiquimod-loaded polymeric nanocapsules (NCimiq) showed significant time-dependent decrease in cell viability after treatment at 3 μmol L^-1 (79% viable cells in 24 h and 55% in 72 h), which was not observed in cells treated with the solution of the drug (IMIQ) (99% viable cells in 24 h and 91% in 72 h). The second objective was to develop the hydrogel containing the drug-loaded nanocapsules (PEC-NCimiq). In vitro release study showed that 63% of imiquimod was released from the pectin-based hydrogel containing the drug (PEC-imiq) after 2 h, while 60% of the drug was released from PEC-NCimiq after 8 h. In the permeation study, 2.5 μg of imiquimod permeated the skin within 8 h after the initial contact of PEC-NCimiq, whereas only 2.1 μg of drug permeated after 12 h of contact when PEC-imiq was assayed. Pectin-based hydrogels enabled the drug penetration in all skin layers, especially the dermis (PEC-NCimiq = 6.8 μg and PEC-imiq = 4.3 μg). In the adhesion study, PEC-NCimiq showed the highest adhesiveness (42% removed from the skin) in comparison to PEC-imiq (71% removed from the skin). In conclusion, the nanoencapsulation provided a higher cytotoxic effect of imiquimod in SK-MEL-28, and the incorporation of the drug-loaded nanocapsules in pectin-based hydrogel showed higher adhesiveness and deeper penetration of the drug into the skin. Graphical abstract.

Redispersible Spray-Dried Powder Containing Nanoencapsulated Curcumin: the Drying Process Does Not Affect Neuroprotection In vitro

A redispersible spray-dried formulation containing curcumin-loaded, lipid-core nanocapsules (LNC-C) was developed for oral administration. The neuroprotective activity of curcumin after the spray-drying process was evaluated in vitro. The spray-dried powder (SD-LNC-C) was produced using a drying adjuvant composed of a blend of maltodextrin and L-leucine (90:10 w/w). Acceptable process yield (~ 70%) and drug content (6.5 ± 0.2 mg g^-1) were obtained. SD-LNC-C was formed by smooth, spherical-shaped particles, and confocal Raman analysis indicated the distribution of the LNC-C on the surface of the leucine/maltodextrin agglomerates. The surface of the agglomerates was formed by a combination of LNC-C and adjuvants, and laser diffraction showed that SD-LNC-C had adequate aqueous redispersion, with no loss of controlled drug release behaviour of LNC-C. The in vitro curcumin activity against the lipopolysaccharide (LPS)-induced proinflammatory response in organotypic hippocampal slice cultures was evaluated. Both formulations (LNC-C and SD-LNC-C) reduced TNF-α to similar levels. Therefore, neuroprotection of curcumin in vitro may be improved by nanoencapsulation followed by spray-drying, with no loss of this superior performance. Hence, the redispersible spray-dried powder proposed here represents a suitable approach for the development of innovative nanomedicines containing curcumin for the prevention/treatment of neurodegenerative diseases.

Eugenol as a Promising Molecule for the Treatment of Dermatitis: Antioxidant and Anti-inflammatory Activities and Its Nanoformulation

Contact dermatitis produces an inflammatory reaction primarily via stimulation of keratinocytes and cells of the immune system, which promote the release of cytokines, reactive oxygen species (ROS), and other chemical mediators. Eugenol (EUG, phenylpropanoid of essential oils) has attracted attention due to its anti-inflammatory properties, as well as antioxidant effect. On the other hand, it is volatile and insoluble and is a skin irritant. In this case, nanostructured systems have been successfully employed as a drug carrier for skin diseases since they improve both biological and pharmaceutical properties of active compounds. The cytotoxic, antioxidant, and anti-inflammatory effects of EUG were assessed in human neutrophils and keratinocytes. Additionally, polymeric nanocarries (NCEUG) were prepared to improve the chemical and irritant characteristics of EUG. EUG presented apparent safety and antioxidant and anti-inflammatory effects on human neutrophils, but presented cytotoxic effects on keratinocytes. However, the nanocapsules were able to reduce its cytotoxicity. An in vivo experiment of irritant contact dermatitis (ICD) in mice induced by TPA showed that NCEUG reduced significantly the ear edema in mice when compared to the EUG solution, as well as the leukocyte infiltration and IL-6 level, possibly due to better skin permeation and irritancy blockage. These findings suggest that EUG is a promising bioactive molecule, and its nanoencapsulation seems to be an interesting approach for the treatment of ICD.

Nanoemulsion as pharmaceutical carrier for dermal and transdermal drug delivery: Formulation development, stability issues, basic considerations and applications

The use of nanoemulsion in augmenting dermal and transdermal effectiveness of drugs has now well established. The development of nanoemulsion based semisolid dosage forms is an active area of present research. However, thickening or liquid-to-semisolid conversion of the nanoemulsions provides opportunities to the formulation scientist to explore novel means of solving instability issues during transformation. Extending knowledge about the explicit role of nature/magnitude of zeta potential, types of emulsifiers and selection of appropriate semisolid bases could place these versatile carriers from laboratory to industrial scale. This article reviews the progressive advancement in the delivery of medicament via nanoemulsion with special reference to the dermal and transdermal administration. It is attempted to explore the most suitable semi solid dosage form for the particular type of nanoemulsion (o/w, w/o and others) and effect of particle size and zeta potential on the delivery of drugs through dermal or transdermal route. Finally, this review also highlights the basic principles and fundamental considerations of nanoemulsion manufacture, application of nanoemulsion based semisolid dosage forms in the dermal/transdermal administration and basic considerations during the nanoemulsion absorption into and through skin.

Redispersible spray-dried lipid-core nanocapsules intended for oral delivery: the influence of the particle number on redispersibility

This study proposes a new approach to produce easily redispersible spray-dried lipid-core nanocapsules (LNC) intended for oral administration, evaluating the influence of the particle number density of the fed sample. The proposed approach to develop redispersible spray-dried LNC formulations intended for oral route is innovative, evidencing the needing of an optimization of the initial particle number density in the liquid suspension of nanocapsules. A mixture of maltodextrin and L-leucine (90:10 w/w) was used as drying adjuvant. Dynamic light scattering, turbidimetry, determination of surface area and pore size distribution, electron microscopy and confocal Raman microscopy (CRM) were used to characterize the proposed system and to better understand the differences in the redispersion behavior. An easily aqueous redispersion of the spray-dried powder composed of maltodextrin and L-leucine (90:10 w/w) was obtained, depending on the particle number density. Their surface area decreased in the presence of LNC. CRM enabled the visualization of the spatial distribution of the different compounds in the powders affording to better understand the influence of the particle number density of the fed sample on their redispersion behavior. This study shows the need for optimizing initial particle number density in the liquid formulation to develop redispersible spray-dried LNC powders.

Sepsis induced by cecal ligation and perforation (CLP) alters nucleotidase activities in platelets of rats

Sepsis is a potentially lethal condition, and it is associated with platelet alterations. The present study sought to investigate the activity of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase), E-5'-nucleotidase, and ecto-adenosine deaminase (E-ADA) in the platelets of rats that were induced with sepsis. Male Wistar rats were divided into three groups of ten animals each: a negative control group (normal; NC); a group that underwent surgical procedures (sham); and a group that underwent cecal ligation and perforation (CLP). The induction of sepsis was confirmed by bacteremia, and the causative pathogen identified was Escherichia coli. Hematological parameters showed leukocytosis and thrombocytopenia in animals in the septic group. The results also revealed that there were significant (p < 0.05) increases in adenosine triphosphate (ATP) and adenosine monophosphate (AMP) hydrolyses, and in the deamination of adenosine in the CLP group compared to the sham and control groups. Conversely, ADP hydrolysis was significantly decreased (p < 0.05) in the CLP group compared to the sham and control groups. Purine levels were analyzed by high-performance liquid chromatography (HPLC) in serum samples from control, sham, and CLP groups. Increased concentrations of ATP, adenosine, and inosine were found in the CLP group compared to the sham and control groups. Conversely, the concentrations of ADP and AMP in the CPL group were not significantly altered. We suggest that alterations in hematological parameters, nucleotide hydrolysis in platelets, and nucleotide concentrations in serum samples of rats with induced sepsis may be related to thromboembolic events.

In Vivo Assessment of Clobetasol Propionate-Loaded Lecithin-Chitosan Nanoparticles for Skin Delivery

The aim of this work was to assess in vivo the anti-inflammatory efficacy and tolerability of clobetasol propionate (CP) loaded lecithin/chitosan nanoparticles incorporated into chitosan gel for topical application (CP 0.005%). As a comparison, a commercial cream (CP 0.05% w/w), and a sodium deoxycholate gel (CP 0.05% w/w) were also evaluated. Lecithin/chitosan nanoparticles were prepared by self-assembling of the components obtained by direct injection of soybean lecithin alcoholic solution containing CP into chitosan aqueous solution. Nanoparticles obtained had a particle size around 250 nm, narrow distribution (polydispersity index below 0.2) and positive surface charge, provided by a superficial layer of the cationic polymer. The nanoparticle suspension was then loaded into a chitosan gel, to obtain a final CP concentration of 0.005%. The anti-inflammatory activity was evaluated using carrageenan-induced hind paw edema test on Wistar rats, the effect of formulations on the barrier property of the stratum corneum were determined using transepidermal water loss measurements (TEWL) and histological analysis was performed to evaluate the possible presence of morphological changes. The results obtained indicate that nanoparticle-in-gel formulation produced significantly higher edema inhibition compared to other formulations tested, although it contained ten times less CP. TEWL measurements also revealed that all formulations have no significant disturbance on the barrier function of skin. Furthermore, histological analysis of rat abdominal skin did not show morphological tissue changes nor cell infiltration signs after application of the formulations. Taken together, the present data show that the use of lecithin/chitosan nanoparticles in chitosan gel as a drug carrier significantly improves the risk-benefit ratio as compared with sodium-deoxycholate gel and commercial cream formulations of CP.

Nanoparticle-Enabled Transdermal Drug Delivery Systems for Enhanced Dose Control and Tissue Targeting

Transdermal drug delivery systems have been around for decades, and current technologies (e.g., patches, ointments, and creams) enhance the skin permeation of low molecular weight, lipophilic drugs that are efficacious at low doses. The objective of current transdermal drug delivery research is to discover ways to enhance skin penetration of larger, hydrophilic drugs and macromolecules for disease treatment and vaccination. Nanocarriers made of lipids, metals, or polymers have been successfully used to increase penetration of drugs or vaccines, control drug release, and target drugs to specific areas of skin in vivo. While more research is needed to identify the safety of nanocarriers, this technology has the potential to expand the use of transdermal routes of administration to a wide array of therapeutics. Here, we review the current state of nanoparticle skin delivery systems with special emphasis on targeting skin diseases.

Nanoencapsulation of Rose-Hip Oil Prevents Oil Oxidation and Allows Obtainment of Gel and Film Topical Formulations

The rose-hip oil holds skin regenerating properties with applications in the dermatological and cosmetic area. Its nanoencapsulation might favor the oil stability and its incorporation into hydrophilic formulations, besides increasing the contact with the skin and prolonging its effect. The aim of the present investigation was to develop suitable rose-hip-oil-loaded nanocapsules, to verify the nanocapsule effect on the UV-induced oxidation of the oil and to obtain topical formulations by the incorporation of the nanocapsules into chitosan gel and film. The rose-hip oil (500 or 600 μL), polymer (Eudragit RS100®, 100 or 200 mg), and acetone (50 or 100 mL) contents were separately varied aiming to obtain an adequate size distribution. The results led to a combination of the factors acetone and oil. The developed formulation showed average diameter of 158 ± 6 nm with low polydispersity, pH of 5.8 ± 0.9, zeta potential of +9.8 ± 1.5 mV, rose-hip oil content of 54 ± 1 μL/mL and tendency to reversible creaming. No differences were observed in the nanocapsules properties after storage. The nanoencapsulation of rose-hip oil decreased the UVA and UVC oxidation of the oil. The chitosan gel and film containing rose-hip-oil-loaded nanocapsules showed suitable properties for cutaneous use. In conclusion, it was possible to successfully obtain rose-hip-oil-loaded nanocapsules and to confirm the nanocapsules effect in protecting the oil from the UV rays. The chitosan gel and film were considered interesting alternatives for incorporating the nanoencapsulated rose-hip oil, combining the advantages of the nanoparticles to the advantages of chitosan.

Clobetasol-loaded nanostructured lipid carriers for epidermal targeting

Objectives

The aim of this study was to investigate in vitro the epidermal targeting potential of clobetasol propionate-loaded nanostructured lipid carriers (CP-NLC) when compared to that of chitosan-coated (CP-NLC-C).

Methods

CP-NLC were prepared by microemulsion method and characterized by dynamic light scattering, transmission electron microscopy, in vitro release and permeation studies. To verify epidermal targeting, permeation studies were performed in two sets of experiments. For the first set, the skin was removed from the diffusion cell and stratum corneum (SC) was separated from the remaining skin (RS). For the second set, the whole epidermis (EP) was separated from the dermis (DER). CP quantification was performed in each skin layer.

Key findings

A novel clobetasol propionate-loaded NLC was produced with 1/5th of the drug dose used in commercial formulations and, even so, presented greater skin permeation. Both chitosan-coated and uncoated NLC enhanced the amount of CP in the epidermis more than 80-fold when compared to the commercial formulation (20.26 ± 2.77; 17.85 ± 0.49 and 0.22 ± 0.02 μg/cm2, respectively). Differently from chitosan-coated NLC, the uncoated NLC did not show dermal retention.

Conclusions

NLC proved to be a system with potential for targeting drug delivery to the epidermal layer.

Assessing the In Vitro Drug Release from Lipid-Core Nanocapsules: a New Strategy Combining Dialysis Sac and a Continuous-Flow System

The in vitro assessment of drug release from polymeric nanocapsules suspensions is one of the most studied parameters in the development of drug-loaded nanoparticles. Nevertheless, official methods for the evaluation of drug release from submicrometric carriers are not available. In this work, a new approach to assess the in vitro drug release profile from drug-loaded lipid-core nanocapsules (LNC) was proposed. A continuous-flow system (open system) was designed to evaluate the in vitro drug release profiles from different LNC formulations containing prednisolone or clobetasol propionate (LNC-CP) as drug model (LNC-PD) using a homemade apparatus. The release medium was constantly renewed throughout the experiment. A dialysis bag containing 5 mL of formulation (0.5 mg mL(-1)) was maintained inside the apparatus, under magnetic stirring and controlled temperature (37°C). In parallel, studies based on the conventional dialysis sac technique (closed system) were performed. It was possible to discriminate the in vitro drug release profile of different formulations using the open system. The proposed strategy improved the sink condition, by constantly renewing the release medium, thus maintaining the drug concentration farther from the saturated concentration in the release medium. Moreover, problems due to sampling errors can be easily overcome using this semi-automated system, since the collection is done automatically without interference from the analyst. The system proposed in this paper brings important methodological and analytical advantages, becoming a promising prototype semi-automated apparatus for performing in vitro drug release studies from drug-loaded lipid-core nanocapsules and other related nanoparticle drug delivery systems.

Co-encapsulation of imiquimod and copaiba oil in novel nanostructured systems: promising formulations against skin carcinoma

In this study, two types of cutaneous-directed nanoparticles are proposed for the co-encapsulation of imiquimod (a drug approved for the treatment of basal cell carcinoma) and copaiba oil (oil that exhibits anti-proliferative properties). Nanostructured copaiba capsules (NCCImq) were prepared using the interfacial deposition method, and nanostructured Brazilian lipids (NBLImq) were prepared by high-pressure homogenization. The formulations exhibited average diameter, zeta potential, pH and drug content of approximately 200nm, -12mV, 6 and 1mgmL(-1), respectively. In addition, the formulations exhibited homogeneity regarding particle size, high encapsulation efficiency and stability. Both nanocarriers controlled imiquimod release, and NBLImq exhibited slower drug release (p < 0.05), likely due to increased interaction of the drug with the solid lipid (cupuaçu seed butter). The in vitro evaluation of the imiquimod-loaded nanocarriers was performed using healthy skin cells (keratinocytes, HaCaT); no alteration was observed, suggesting the biocompatibility of the nanocarriers. In addition, in vitro skin permeation/penetration using pig skin was performed, and NCCImq led to increased drug retention in the skin layers and reduced amounts of drug found in the receiver solution. Thus, NCCImq is considered the most promising nanoformulation for the treatment of skin carcinoma.

Clozapine linked to nanocapsules minimizes tissue and oxidative damage to biomolecules lipids, proteins and DNA in brain of rats Wistar

Clozapine, atypical antipsychotic, can change oxidative stress parameters. It is known that reactive species, in excess, can have a crucial role in the etiology of diseases, as well as, can potentiating adverse effects induce by drugs. The nanocapsules have attracted attention as carriers of several drugs, with consequent reduction of adverse effects. This study aimed to evaluate histopathology and oxidative damage of biomolecules lipids, proteins and DNA in the brain of Wistar rats after treatment with nanocapsules containing clozapine. The study consisted of eight groups of male Wistar rats (n = 6): saline (SAL), free clozapine (CZP) (25 mg/Kg i.p.), blank uncoated nanocapsules (BNC), clozapine-loaded uncoated nanocapsules (CNC) (25 mg/Kg i.p.), blank chitosan-coated nanocapsules (BCSN), clozapine-loaded chitosan-coated nanocapsules (CCSN) (25 mg/Kg i.p.), blank polyethyleneglycol-coated nanocapsules (BPEGN), clozapine-loaded polyethyleneglycol-coated nanocapsules (CPEGN) (25 mg/Kg i.p.). The animals received the formulation once a day for seven consecutive days and euthanized in the eighth day. After euthanasia, the brain was collected and homogenate was processed for further analysis. The histopathology showed less brain tissue damage in nanocapsules-treated groups. The lipid peroxidation and carbonylation of proteins showed a significant increase (p < 0.05) induced by CZP. CNC and CPEGN groups obtained a reduction membrane of lipids damage and nanocapsules-treated groups showed significant improvement protein damage. CZP was able to induce genetic oxidative damage, while the nanocapsules causing less damage to DNA. The findings show that different coatings can act protecting target tissues decreasing oxidative damage, suggesting that the drug when linked to different nanocapsules is able to mitigate the harmful effects of clozapine.

Nanoencapsulation of rice bran oil increases its protective effects against UVB radiation-induced skin injury in mice

Excessive UV-B radiation by sunlight produces inflammatory and oxidative damage of skin, which can lead to sunburn, photoaging, and cancer. This study evaluated whether nanoencapsulation improves the protective effects of rice bran oil against UVB radiation-induced skin damage in mice. Lipid-core nanocapsules containing rice bran oil were prepared, and had mean size around 200 nm, negative zeta potential (∼-9 mV), and low polydispersity index (<0.20). In order to allow application on the skin, a hydrogel containing the nanoencapsulated rice bran oil was prepared. This formulation was able to prevent ear edema induced by UVB irradiation by 60 ± 9%, when compared with a hydrogel containing LNC prepared with a mixture of medium chain triglycerides instead of rice bran oil. Protein carbonylation levels (biomarker of oxidative stress) and NF-κB nuclear translocation (biomarker of pro-inflammatory and carcinogenesis response) were reduced (81% and 87%, respectively) in animals treated with the hydrogel containing the nanoencapsulated rice bran oil. These in vivo results demonstrate the beneficial effects of nanoencapsulation to improve the protective properties of rice bran oil on skin damage caused by UVB exposure.

Physical chemistry evaluation of stability, spreadability, in vitro antioxidant, and photo-protective capacities of topical formulations containing Calendula officinalis L. leaf extract

Calendula is used widely in cosmetic formulations that present phenolic compounds in their chemical constitution. The objective of our research was to develop and evaluate the stability of topical formulations containing 5% hydro-ethanolic extract of calendula leaves, including spreadability, and in vitro photo-protective, and antioxidant capacity. To evaluate the stability, we used organoleptic characteristics, pH, and viscosity parameters. Antioxidant capacity was measured by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, and the photo-protective capacity by SPF spectrophotometric measure. All formulations were stable. The calendula extract formulations in gel and cream showed no significant variations in pH, and the cream formulations presented lower viscosity variations than gel formulations. The spreadability of the gel formulations was superior to those in cream. The formulations also presented good antioxidant capacities and an FPS of around 1.75. In accordance with the results, the formulations can be used as antioxidants, but considering the low SPF obtained, calendula cannot be considered as a stand-alone sunscreen, yet may well be tested in future studies towards verifying enhancement of synthetic sunscreens.

Co-encapsulation of resveratrol and curcumin in lipid-core nanocapsules improves their in vitro antioxidant effects

Resveratrol and curcumin are natural antioxidants found in the human diet that have been used in the prevention and treatment of different diseases associated with oxidative stress. Aiming to improve the antioxidant effects of resveratrol and curcumin, lipid-core nanocapsules containing the combination of both polyphenols were developed. Physicochemical characteristics were evaluated and compared to the formulations containing each polyphenol individually. Co-encapsulation did not influence nanotechnological characteristics, and all formulations presented mean diameter around 200 nm, low polydispersity index, and encapsulation efficiency close to 100%. Nanoencapsulation increases the photostability of resveratrol and curcumin, and co-encapsulation improves resveratrol photostability. The in vitro antioxidant activity of polyphenols against HO radicals was enhanced by nanoencapsulation, and a better effect was observed after their co-nanoencapsulation. Also, nanocapsules exhibited controlled release profile, for both polyphenols. The results showed that the strategy to co-encapsulate resveratrol and curcumin is a promising approach to improve the performance of medicines used to prevent and treat diseases associated with oxidative stress.

The use of nanoencapsulation to decrease human skin irritation caused by capsaicinoids

Capsaicin, a topical analgesic used in the treatment of chronic pain, has irritant properties that frequently interrupt its use. In this work, the effect of nanoencapsulation of the main capsaicinoids (capsaicin and dihydrocapsaicin) on skin irritation was tested in humans. Skin tolerance of a novel vehicle composed of chitosan hydrogel containing nonloaded nanocapsules (CH-NC) was also evaluated. The chitosan hydrogel containing nanoencapsulated capsaicinoids (CH-NC-CP) did not cause skin irritation, as measured by an erythema probe and on a visual scale, while a formulation containing free capsaicinoids (chitosan gel with hydroalcoholic solution [CH-ET-CP]) and a commercially available capsaicinoids formulation caused skin irritation. Thirty-one percent of volunteers reported slight irritation one hour after application of CH-NC-CP, while moderate (46% [CH-ET-CP] and 23% [commercial product]) and severe (8% [CH-ET-CP] and 69% [commercial product]) irritation were described for the formulations containing free capsaicinoids. When CH-NC was applied to the skin, erythema was not observed and only 8% of volunteers felt slight irritation, which demonstrates the utility of the novel vehicle. A complementary in vitro skin permeation study showed that permeation of capsaicinoids through an epidermal human membrane was reduced but not prevented by nanoencapsulation.

An experimental model of contact dermatitis: evaluation of the oxidative profile of Wistar rats treated with free and nanoencapsulated clobetasol

OBJECTIVE

An experimental animal model of contact dermatitis (CD) was used to investigate the effects of free and nanoencapsulated clobetasol propionate on the skin and on the oxidative profile of liver tissue.

METHODS

Female Wistar rats were divided into six groups, each containing eight rats. The first group, control (C), was sensitized with solid vaseline. Group 2, (CD), was sensitized with 5% NiSO(4). Groups 3 and 4 were sensitized with 5% NiSO(4) and treated with free (FC) and nanoencapsulated (NC) clobetasol (0.42 mg/g), respectively, daily for 5 days. Group 5 was treated with nanoencapsulated clobetasol (0.42 mg/g) on days 1, 3, and 5 (C135) and group 6 received a hydrogel containing empty nanoparticles (NP) daily for 5 days. Thiobarbituric acid reactive substances (TBARS), carbonyl levels, non-protein sulfhydryl groups (NPSH) and catalase activity were measured in liver homogenates.

RESULTS

A significant increase was observed in the levels of TBARS, NPSH, and catalase activity for the groups CD and NP.

DISCUSSION

Our results suggest that both NiSO(4) sensitization and NP administration induced oxidation of cellular lipids and activated the antioxidant enzyme catalase to protect from this damage. These results also indicated that daily treatment with the free and nanoencapsulated clobetasol, as well as treatment with the nanoencapsulated clobetasol every other day, were able to prevent these redox alterations and protect against histological damage.

Enhanced dermal delivery of diflucortolone valerate using lecithin/chitosan nanoparticles: in-vitro and in-vivo evaluations

The objective of this study was to prepare a suitable formulation for dermal delivery of diflucortolone valerate (DFV) that would maintain the localization in skin layers without any penetration and to optimize efficiency of DFV. Drug-loaded lecithin/chitosan nanoparticles with high entrapment efficiency (86.8%), were successfully prepared by ionic interaction technique. Sustained release of DFV was achieved without any initial burst release. Nanoparticles were also incorporated into chitosan gel at different ratios for preparing a more suitable formulation for topical drug delivery with adequate viscosity. In ex-vivo permeation studies, nanoparticles increased the accumulation of DFV especially in the stratum corneum + epidermis of rat skin without any significant permeation. Retention of DFV from nanoparticle in chitosan gel formulation (0.01%) was twofold higher than commercial cream, although it contained ten times less DFV. Nanoparticles in gel formulations produced significantly higher edema inhibition in rats compared with commercial cream in in-vivo studies. Skin blanching assay using a chromameter showed vasoconstriction similar to that of the commercial product. There were no barrier function changes upon application of nanoparticles. In-vitro and in-vivo results demonstrated that lecithin/chitosan nanoparticles in chitosan gel may be a promising carrier for dermal delivery of DFV in various skin disorders.

In vitro skin penetration of clobetasol from lipid nanoparticles: drug extraction and quantitation in different skin layers

Clobetasol propionate (CP) is a potent topical corticosteroid that causes several cutaneous and systemic side effects. In the present work, CP was encapsulated in nanostructured lipid carriers (NLCs) to increase drug retention in the outer skin layers and improve the safety of topical therapy. NLCs were prepared using a microemulsion technique with a mixture of lecithin, taurodeoxycholate, stearic acid, and oleic acid. In vitro penetration studies were performed in a modified Franz-type diffusion cell, and porcine ears were used as a model of human skin. A simple and sensitive liquid chromatographic method was developed and validated for clobetasol determination in different skin layers. NLCs presented uniform size distribution, high zeta potentialand entrapment efficiency values (> 98%). The analytical procedure was validated according to FDA guidelines. Clobetasol recoveries from skin samples were higher than 85%, with no interference of skin components and NLC ingredients. In experiments, after 6 h, a higher drug accumulation in the stratum corneum arising from NLCs compared to aqueous CP solution was observed. Thus, the NLCs demonstrated high potential for targeting CP to the skin and ensuring drug accumulation in the stratum corneum.