Incorporation of Eugenia dysenterica extract in microemulsions preserves stability, antioxidant effect and provides enhanced cutaneous permeation

The amazing native Brazilian fruits

A number of native Brazilian plant species are under exploited by the scientific community, despite the country's precious biodiversity. The vast majority of native Brazilian fruits (NBF) is source of compounds that provide many health benefits and can potentially be used to prevent diseases and formulate high-added value products. This review covers the scientific research over the last decade (2012-2022) on eight NBF, and focuses on information about the production and market panorama, physical description, physicochemical characterization, nutritional composition, their functional value of bioactive compounds and health benefits, as well as the potential for utilizations for each. The studies herein compiled reveal the outstanding nutritional value of these NBF. They are sources of vitamins, fibers, minerals and bioactive compounds that exhibit antioxidant activity, and they contain phytochemicals with anti-inflammatory action, anti-obesity and other functions that bring many health benefits to consumers. NBF can be also used as raw material for multiple products such as nectars, juices, jams, frozen pulps, liquor, among others. The dissemination of knowledge about NBF has fundamental implications worldwide.

In vitro diffusion of plant phenolics through the skin: A review update

OBJECTIVE

Excessive skin exposure to deleterious environmental variables results in inflammation as well as molecular and cellular impairments that compromise its functionality, aesthetic qualities, and overall well-being. The implementation of topical administration of antioxidants and other compounds as a method for preventing or reversing damage is a rational approach. Numerous phenolic compounds derived from plants have demonstrated capabilities such as scavenging free radicals and promoting tissue healing. However, the primary obstacle lies in effectively delivering these compounds to the specific place on the skin, and accurately forecasting their diffusion through the skin can assist in determining the most effective tactics. Hence, this article provides a comprehensive analysis of recent literature pertaining to the in vitro skin diffusion characteristics of plant phenolics. The aim is to gain a deeper understanding of their behaviour when present in various forms such as solutions, suspensions, and formulations.

METHOD

The data on plant extracts and isolated plant phenolic compounds in vitro skin diffusion assays published over the last six years were compiled and discussed.

RESULTS

Even though the gold standard Franz diffusion cell is the most commonly used in the assessment of in vitro plant phenolic skin diffusion profiles, a plethora of skin models and assay conditions are reported for a variety of compounds and extracts in different vehicles.

CONCLUSION

The presence of numerous models and vehicles poses a challenge in creating correlations among the existing data on plant phenolic compounds. However, it is possible to draw some general conclusions regarding molecular, vehicle, and skin characteristics based on the gathered information.

Iontophoresis for the cutaneous delivery of nanoentraped drugs

INTRODUCTION

The skin is an attractive route for drug delivery. However, the stratum corneum is a critical limiting barrier for drug permeation. Nanoentrapment is a way to enhance cutaneous drug delivery, by diverse mechanisms, with a notable trend of nanoparticles accumulating into the hair follicles when topically applied. Iontophoresis is yet another way of increasing drug transport by applying a mild electrical field that preferentially passes through the hair follicles, for being the pathway of lower resistance. So, iontophoresis application to nanocarriers could further increase actives accumulation into the hair follicles, impacting cutaneous drug delivery.

AREAS COVERED

In this review, the authors aimed to discuss the main factors impacting iontophoretic skin transport when combining nanocarriers with iontophoresis. We further provide an overview of the conditions in which this combination has been studied, the characteristics of nanosystems employed, and hypothesize why the association has succeeded or failed to enhance drug permeation.

EXPERT OPINION

Nanocarriers and iontophoresis association can be promising to enhance cutaneous drug delivery. For better results, the electroosmotic contribution to the iontophoretic transport, mainly of negatively charged nanocarriers, charge density, formulation pH, and skin models should be considered. Moreover, the transfollicular pathway should be considered, especially when designing the nanocarriers.

Anti-inflammatory effect evaluation of naringenin and its incorporation into a chitosan-based film for transdermal delivery

Naringenin is a bioflavonoid mainly found in citrus fruits. It presents many pharmacological benefits, including a remarkable anti-inflammatory activity, but its oral bioavailability is poor. To overcome this drawback, this work proposes a transdermal administration of such bioflavonoid, considering its use in the chronic treatment of inflammatory conditions. For this, it aims to develop a chitosan-based film that guarantees a consistent transdermal delivery of the drug. First, naringenin's in vitro anti-inflammatory effect on T-cell proliferation was evaluated, followed by research on the modulation of gene expression for inflammatory factors in peripheral blood mononuclear cells. Chitosan films were then prepared and characterized. Afterward, naringenin release profile from a selected film was determined as well as the drug permeation across porcine skin provided by the film. Naringenin induced the expression of the anti-inflammatory factors IL-10 and TGF-β1 while inhibiting the expression of the pro-inflammatory cytokine IL-1β and limiting T-cell proliferation. The chitosan film was successfully developed, and the drug was progressively released to the physiological media following both first order and Korsmeyer-Peppas kinetics. When topically applied, the chitosan film guaranteed a constant and continuous diffusion of naringenin across the skin over 72 h. Indeed, the permeation flux of naringenin was 0.30 ± 0.01 µg/cm²/h, which means a concentration in the receptor solution 14-fold (p < 0.05) higher than that provided by the drug solution. Thus, the chitosan film represents a promising transdermal alternative for the long-term treatment of inflammatory conditions using naringenin.

Pouteria macrophylla Fruit Extract Microemulsion for Cutaneous Depigmentation: Evaluation Using a 3D Pigmented Skin Model

Here, we verify the depigmenting action of Pouteria macrophylla fruit extract (EXT), incorporate it into a safe topical microemulsion and assess its effectiveness in a 3D pigmented skin model. Melanocytes-B16F10- were used to assess the EXT effects on cell viability, melanin synthesis, and melanin synthesis-related gene transcription factor expression, which demonstrated a 32% and 50% reduction of intra and extracellular melanin content, respectively. The developed microemulsion was composed of Cremophor EL^®/Span 80 4:1 (w/w), ethyl oleate, and pH 4.5 HEPES buffer and had an average droplet size of 40 nm (PdI 0.40 ± 0.07). Skin irritation test with reconstituted epidermis (Skin Ethic RHE^TM) showed that the formulation is non-irritating. Tyrosinase inhibition was maintained after skin permeation in vitro, in which microemulsion showed twice the inhibition of the conventional emulsion (20.7 ± 2.2% and 10.7 ± 2.4%, respectively). The depigmenting effect of the microemulsion was finally confirmed in a 3D culture model of pigmented skin, in which histological analysis showed a more pronounced effect than a commercial depigmenting formulation. In conclusion, the developed microemulsion is a promising safe formulation for the administration of cutite fruit extract, which showed remarkable depigmenting potential compared to a commercial formulation.

Recent developments in industrial applications of nanoemulsions

Nanotechnology is being utilized in various industries to increase the quality, safety, shelf-life, and functional performance of commercial products. Nanoemulsions are thermodynamically unstable colloidal dispersions that consist of at least two immiscible liquids (typically oil and water), as well as various stabilizers (including emulsifiers, texture modifiers, ripening inhibitors, and weighting agents). They have unique properties that make them particularly suitable for some applications, including their small droplet size, high surface area, good physical stability, rapid digestibility, and high bioavailability. This article reviews recent developments in the formulation, fabrication, functional performance, and gastrointestinal fate of nanoemulsions suitable for use in the pharmaceutical, cosmetic, nutraceutical, and food industries, as well as providing an overview of regulatory and health concerns. Nanoemulsion-based delivery systems can enhance the water-dispersibility, stability, and bioavailability of hydrophobic bioactive compounds. Nevertheless, they must be carefully formulated to obtain the required functional attributes. In particular, the concentration, size, charge, and physical properties of the nano-droplets must be taken into consideration for each specific application. Before launching a nanoscale product onto the market, determination of physicochemical characteristics of nanoparticles and their potential health and environmental risks should be evaluated. In addition, legal, consumer, and economic factors must also be considered when creating these systems.

Improved skin permeability and whitening effect of catechin-loaded transfersomes through topical delivery

The aim of the study was to prepare catechin-loaded transfersomes to enhance drug permeability through topical administration for the skin protection against ultraviolet radiation induced photo-damage. The results showed that the catechin-loaded transfersomes were monodispersed with polydispersity index (PDI) < 0.2, <200 nm in particle size and with high encapsulation efficiency (E.E.%) greater than 85%. The in vitro skin permeation test indicated that the catechin-loaded transfersomes enhanced the skin permeability by 85% compared to the catechin aqueous solution. Similarly, the in-vivo skin whitening study demonstrated that F5 transfersome formulation was effective in tyrosinase inhibition and had good biocompatibility to the guinea pig skin. Finally, the stability study showed that both physicochemical properties and E.E.% of the F5 transferosome formulation were fairly stable after 3 months storage. Therefore, topical administration of catechin-loaded transfersomes could be considered as a potential strategy for the treatment of UV-induced oxidative damage to the skin.

Follicular-targeted delivery of spironolactone provided by polymeric nanoparticles

This study proposes developing a topical formulation based on poly-ε-caprolactone (PCL) or methacrylic acid/methyl methacrylate copolymer (EL100) nanoparticles to enable a safer and more effective therapy of alopecia and acne with spironolactone. The effect of the size of the nanoparticle on follicular-targeted drug delivery is also verified. Compatibility studies based on thermal analyses and complementary techniques showed a small interaction of the drug with excipients, which may not compromise the drug stability. PCL nanoparticles of 180.0 ± 1.6 and 126.8 ± 1.0 nm, and EL100 nanoparticles of 102.7 ± 7.1 nm were then prepared. All nanoparticles entrapped more than 75 % of spironolactone, were physically stable, and stabilized the drug for at least 90 days. They were also non-irritant according to HET-CAM tests. Drug release from the nanoparticles was reduced in aqueous buffer media but fast when in contact with oil. Finally, in vitro skin penetration experiments revealed the largest nanoparticles (of 180 nm) targeted drug delivery to the hair follicles 5-fold (p < 0.05) more than the control solution, 2.1-fold (p < 0.05) more than nanoparticles produced with the same polymer (PCL) but with smaller size (123 nm), and 4.9-fold (p < 0.05) more than the 102-nm E100 nanoparticles. In conclusion, follicular targeting can be adjusted according to nanoparticle size, and this work succeeded in obtaining polymeric nanoparticles adequate to enable topical treatment of acne and alopecia with spironolactone.

Physicochemical characterization and nano-emulsification of three species of pumpkin seed oils with focus on their physical stability

We present the chemical composition, quality parameters and antioxidant capacity of pumpkin seed oils (PSO) from Cucurbita pepo, Cucurbita maxima, and Cucurbita moschata cultivated in Brazil. In addition, PSO nanoemulsions (nanopepo, nanomax and nanomosc) were developed and their physical stabilities were assessed under long-term storage at two temperatures. Among the PSO, C. pepo presented the highest contents of polyunsaturated fatty acids, total carotenoids, and chlorophylls, but the lowest oxidative stability. Conversely, C. maxima PSO showed highest oxidative stability and total tocopherol content but the lowest chlorophyll content. Nanomax and nanopepo were more stable to droplet growth at 4 °C, while nanomosc was more stable at 25 °C. Nanopepo was the most stable formulation after the heating-cooling cycles, whereas nanomax was the most stable under centrifugation regardless the temperature. Overall, all nanoemulsions presented droplet diameter lower than 200 nm and ζ-potential approaching -30 mV until the end of storage.

Latanoprost Loaded in Polymeric Nanocapsules for Effective Topical Treatment of Alopecia

Latanoprost has recently been used to treat alopecia as it causes an increase in the capillary density of patients. This work presents for the first time the development of polymeric nanocapsules containing latanoprost for the topical treatment of alopecia. Poly-ε-caprolactone nanocapsules loading latanoprost were developed by nanoprecipitation of the polymer on the surface of drug oily nanodroplets. The method encapsulated 93.9 ± 0.4% of the drug into nanocapsules of 197.8 (± 1.2) nm (PdI = 0.15 ± 0.01). The nanosystem presented a zeta potential equal to - 30.1 ± 1.8 mV and was stable for at least 90 days when stored at 6°C. The colloidal aqueous dispersion was non-irritating, according to the in vitro HET-CAM test. The nanocapsules improved latanoprost accumulation into the hair follicles when topically applied on porcine skin, delivering 30% more drug to these skin structures relative to the control solution (P < 0.05). Also, with a simple manual massage, latanoprost accumulation was increased by twofold (P < 0.05). In conclusion, in addition to being a stable and safe formulation, nanocapsules enhanced latanoprost accumulation into the hair follicles, being a nanosystem with high potential for use as a topical formulation for the treatment of androgenic alopecia.

Phonophoretic application of a glucosamine and chondroitin nanoemulsion for treatment of knee chondropathies

Aim: This study was performed to assess the effect of the phonophoretic application of a nanoemulsion incorporating glucosamine and chondroitin sulfate (NANO-CG) associated with kinesiotherapy on the reduction of pain and stiffness in knee chondropathy. Materials & methods: NANO-CG was tested in vitro and in vivo prior to being applied in a randomized and controlled clinical trial. Results: Cell viability and hen's egg test-chorionallantonic membrane tests indicated the NANO-CG is safe for topical application. Permeation tests showed NANO-CG enhances drug permeation through the skin. There was no statistical significance between treated groups in this preliminary study, however, pain reduction and complete recovery of articular cartilage were observed in some patients treated with NANO-CG. Conclusion: We demonstrate that NANO-CG may be a promising candidate for the therapy of knee chondropathy.