Topical Nanoemulsions as Delivery Systems for Green Extracts of Pterocaulon balansae Aiming at the Treatment of Sporotrichosis.

Coumarins are benzopyrones found in several plant genera, including Pterocaulon (Asteraceae). These compounds represent an important source of new treatments, especially as antimicrobial and antifungal agents. In this study, two coumarin-rich extracts from Pterocaulon balansae using green technologies were obtained through aqueous maceration (AE) and supercritical fluid extraction (SFE). Such extracts were incorporated into nanoemulsions (NAE and NSFE) composed of a medium-chain triglyceride oil core stabilized by phospholipids. The nanoemulsions exhibited droplet sizes between 127 and 162 nm, pH above 5.0, and viscosity of approximately 1.0 cP, properties compatible with the topical route. The coumarins permeation/retention from formulations through ear porcine skin using Franz-type diffusion cells were evaluated. Whatever the extract, coumarins were distributed in skin layers, especially in the dermis in both intact and impaired (tape stripping) skin. In addition, a significant increase in coumarins that reached up to the receptor fluid was observed for impaired skin, with increases of approximately threefold for NAE and fourfold for NSFE. Finally, antifungal activity of nanoemulsions was evaluated according to minimum inhibitory concentrations, and the values were 250 µg/mL for all strains tested. The overall results demonstrated the feasibility of incorporating P. balansae extracts into nanoemulsions and showed a potential alternative for the treatment of sporotrichosis.

Regulatory Framework, Challenges, and Initial Strategic Planning for Advanced Therapy Products (PTAs) Development in Brazil.

Advanced Therapies are a class of innovative complex biological products used for therapeutic purposes, encompassing cell therapy, tissue engineering, and gene therapy products. These are promising therapeutic strategies for several complex diseases with low or non-existent therapeutic alternatives. The proper transposition of basic research in this area into medicinal products must comply with regulatory requirements. Here we review the main regulatory recommendations, emphasizing on the Brazilian regulation. The critical points are the manufacturing process, challenges in characterizing the product, development of non-clinical trials, lack of adequate animal models representative of the clinical situation, and absence of valid and measurable therapeutic endpoints. Based on that, we propose a framework for strategic planning of pre-clinical studies in this field. The detailed example involves producing a nonviral vector-based gene editing product, but the regulations and methods may be extrapolated for developing different types of advanced therapies.

Metastatic Melanoma: A Preclinical Model Standardization and Development of a Chitosan-Coated Nanoemulsion Containing Temozolomide to Treat Brain Metastasis.

Melanoma is the most aggressive type of skin cancer. Brain metastasis is the worst scenario in metastatic melanoma and the treatment options for these patients are limited. Temozolomide (TMZ) is a chemotherapy agent used to treat primary central nervous system tumors. Our objective was to develop chitosan-coated nanoemulsion containing temozolomide (CNE-TMZ) for nasal route administration to melanoma brain metastasis treatment. A preclinical model of metastatic brain melanoma was standardized, and the efficiency of the developed formulation was further determined in vitro and in vivo. The nanoemulsion was done by spontaneous emulsification method and the formulation was characterized by size, pH, polydispersity index, and zeta potential. Culture assessments to determine cell viability were done in the A375 human melanoma cell line. To determine the safety of formulation, healthy C57/BL6 mice were treated with a nanoemulsion without TMZ. The model in vivo used B16-F10 cells implanted by stereotaxic surgery in C57/BL6 mice brains. The results demonstrate that the preclinical model used showed to be useful to analyze the efficiency of new candidate drugs to treat melanoma brain metastasis. The chitosan-coated nanoemulsions with TMZ showed the expected physicochemical characteristics and demonstrated safety and efficacy, reducing around 70% the tumor size compared to control mice, and presenting a tendency in mitotic index reduction, becoming an interesting approach to treat melanoma brain metastasis.

Nasal administration of a temozolomide-loaded thermoresponsive nanoemulsion reduces tumor growth in a preclinical glioblastoma model.

Glioblastoma (GB) is the worst and most common primary brain tumor. Temozolomide (TMZ), an alkylating agent, is widely used for treating primary and recurrent high-grade gliomas. However, at least 50% of TMZ treated patients do not respond to TMZ and the development of chemoresistance is a major problem. Here, we designed a lipid nanoemulsion containing a thermoresponsive polymer (poloxamer 407) aiming to improve TMZ release into the brain via nasal delivery. Increasing amounts of poloxamer 407 were added to preformed nanoemulsions (250 nm-range) obtained by spontaneous emulsification. The influence of the polymer concentration (from 2.5% to 12.5%) and temperature on viscosity was clearly evidenced. Such effect was also noticed on the mucoadhesiveness of formulations, as well as TMZ release rate and retention/permeation through nasal porcine mucosa using Franz-type diffusion cells. From these results, a formulation containing 10% of poloxamer (NTMZ-P10) was selected for further experiments by nasal route. A significantly higher TMZ amount was observed in the brain of rats from NTMZ-P10 in comparison with controls. Finally, our results show that formulation reduced significantly tumor growth by three-fold: 103.88 ± 43.67 mm3 (for NTMZ-P10) and 303.28 ± 95.27 mm3 (control). Overall, these results suggest the potential of the thermoresponsive formulation, administered by the non-invasive nasal route, as a future effective glioblastoma treatment.

Oral Pharmacokinetics of Hydroxycinnamic Acids: An Updated Review.

Hydroxycinnamic acids (HCAs) such as caffeic acid (CA), chlorogenic acid (CGA), coumaric acid (COA) isomers, ferulic acid (FA) and rosmarinic acid (RA) are natural phenolic acids with widespread distribution in vegetal foods and well-documented pharmacological activities. However, the low bioavailability of HCAs impairs their administration by the oral route. The present review addresses new findings and important factors/obstacles for their oral administration, which were unexplored in the reviews published a decade ago concerning the bioavailability of phenolic acids. Based on this, the article aims to perform an updated review of the water solubility and gastrointestinal stability of HCAs, as well as describe their oral absorption, distribution, metabolism and excretion (ADME) processes by in vitro, ex vivo, in situ and in vivo methods.

Effect of Hydrogel Containing Achyrocline satureioides (Asteraceae) Extract-Loaded Nanoemulsions on Wound Healing Activity.

Achyrocline satureioides (Lam.) DC extract-loaded nanoemulsions have demonstrated potential for wound healing, with promising effects on keratinocyte proliferation. We carried out the first in vivo investigation of the wound healing activity of a hydrogel containing A. satureioides extract-loaded nanoemulsions. We prepared hydrogels by adding the gelling agent (Carbopol® Ultrez) to extract-loaded nanoemulsions (~250 nm in diameter) obtained by spontaneous emulsification. The final flavonoid content in formulation was close to 1 mg/mL, as estimated by ultra-fast liquid chromatography. Permeation/retention studies using porcine ear skin showed that flavonoids reached deeper layers of pig ear skin when it was damaged (up to 3.2 µg/cm² in the dermis), but did not reach the Franz-type diffusion cell receptor fluid. For healing activity, we performed a dorsal wound model using Wistar rats, evaluating the lesion size, anti-inflammatory markers, oxidative damage, and histology. We found that extract-loaded formulations promoted wound healing by increasing angiogenesis by ~20%, reducing inflammation (tumor necrosis factor α) by ~35%, decreasing lipid damage, and improving the re-epithelialization process in lesions. In addition, there was an increase in the number of blood vessels and hair follicles for wounds treated with the formulation compared with the controls. Our findings indicate that the proposed formulation could be promising in the search for better quality healing and tissue reconstruction.

Cyclodextrin-Based Delivery Systems and Hydroxycinnamic Acids: Interactions and Effects on Crucial Parameters Influencing Oral Bioavailability-A Review.

Hydroxycinnamic acids (HCAs) are a subclass of phenolic acids presenting caffeic acid (CA), chlorogenic acid (CGA), coumaric acid (COA) isomers, ferulic acid (FA), and rosmarinic acid (RA) as the major representants, being broadly distributed into vegetal species and showing a range of biological potentials. Due to the low oral bioavailability of the HCAs, the development of delivery systems to promote better administration by the oral route is demanding. Among the systems, cyclodextrin (CD)-based delivery systems emerge as an important technology to solve this issue. Regarding these aspects, in this review, CD-based delivery systems containing HCAs are displayed, described, and discussed concerning the degree of interaction and their effects on crucial parameters that affect the oral bioavailability of HCAs.

Gene editing strategies to treat lysosomal disorders: The example of mucopolysaccharidoses.

Lysosomal storage disorders are a group of progressive multisystemic hereditary diseases with a combined incidence of 1:4,800. Here we review the clinical and molecular characteristics of these diseases, with a special focus on Mucopolysaccharidoses, caused primarily by the lysosomal storage of glycosaminoglycans. Different gene editing techniques can be used to ameliorate their symptoms, using both viral and nonviral delivery methods. Whereas these are still being tested in animal models, early results of phase I/II clinical trials of gene therapy show how this technology may impact the future treatment of these diseases. Hurdles related to specific hard-to-reach organs, such as the central nervous system, heart, joints, and the eye must be tackled. Finally, the regulatory framework necessary to advance into clinical practice is also discussed.

Achyrocline satureioides (Lam.) DC (Asteraceae) Extract-Loaded Nanoemulsions as a Promising Topical Wound Healing Delivery System: In Vitro Assessments in Human Keratinocytes (HaCaT) and HET-CAM Irritant Potential.

Achyrocline satureioides (Lam.) DC Asteraceae extracts (ASEs) have been investigated for the treatment of various skin disorders. This study reports the effects of ASE-loaded nanoemulsions (NEASE) on the cellular viability, death by necrosis, and migration of immortalized human keratinocytes (HaCaT cell line), as well as the irritant potential through the hen's egg chorioallantoic membrane test (HET-CAM). NEASE exhibited a polydispersity index above 0.12, with a droplet size of 300 nm, ζ-potential of -40 mV, and content of flavonoids close to 1 mg/mL. No cytotoxicity of the ASE was observed on HaCaT by MTT assay (up to 10 µg/mL). A significant increase of HaCaT viability was observed to NEASE (up to 5 µg/mL of flavonoids), compared to treatment with the ASE. The necrosis death evaluation demonstrated that only NEASE did not lead to cell death at all the tested concentrations. The scratch assay demonstrated that NEASE was able to increase the cell migration at low flavonoid concentrations. Finally, the HET-CAM test proved the non-irritative potential of NEASE. Overall, the results indicate the potential of the proposed formulations for topical use in wound healing, in view of their promising effects on proliferation and migration in keratinocytes, combined with an indication of the absence of cytotoxicity and non-irritating potential.

Optimization of Coumarins Extraction from Pterocaulon balansae by Box-Behnken Design and Anti-Trichomonas vaginalis Activity.

Trichomonas vaginalis causes trichomoniasis, a nonviral sexually transmitted infection with a high prevalence worldwide. Oral metronidazole is the drug of choice for the treatment of this disease, although high levels of T. vaginalis resistance to this agent are well documented in the literature. This study describes the anti-T. vaginalis activity of an optimized coumarin-rich extract from Pterocaulon balansae. Optimization was performed to maximize extraction of total coumarins by means of a 3-level Box-Behnken design, evaluating the effect of three factors: extraction time, plant : solvent ratio, and ethanol concentration. Optimum conditions were found to be 5 h extraction time and a plant : solvent ratio of 1% (w/v) and 60% (v/v) ethanol, which resulted in approximately 30 mg of total coumarins/g of dry plant. The coumarin-enriched extract exhibited a minimum inhibitory concentration of 30 µg/mL and an IC50 of 3.2 µg/mL against T. vaginalis, a low cytotoxicity, and a high selectivity index (18 for vaginal epithelial cells and 16 for erythrocytes). The coumarins permeation/retention profile through porcine vaginal mucosa was evaluated in Franz-type diffusion cells. After 8 h of kinetics, coumarins were detected in the tissue (4.93 µg/g) without detecting them in the receptor compartment. A significant increase of coumarins in the mucosa layers (8.18 µg/g) and receptor compartment (0.26 µg/g) was detected when a T. vaginalis suspension (2 × 105 trophozoites/mL) was previously added onto the mucosa. No alterations were visualized in the stratified squamous non-keratinized epithelium of the porcine vaginal mucosa after contact with the extract. Overall, these results suggest that the P. balansae coumarin-rich extract may have potential as a treatment for trichomoniasis.

Chitosan-coated rosmarinic acid nanoemulsion nasal administration protects against LPS-induced memory deficit, neuroinflammation, and oxidative stress in Wistar rats.

Rosmarinic acid (RA) lipid-nanotechnology-based delivery systems associate with mucoadhesive biopolymers for nasal administration has arisen as a new promising neuroprotective therapy for neurodegenerative disorders (ND). We have previously demonstrated the glioprotective effect of chitosan-coated RA nanoemulsions (RA CNE) against lipopolysaccharide (LPS)-induced damage in rat astrocyte primary culture. Here, we further investigate the protective effect of RA CNE nasal administration on LPS-induced memory deficit, neuroinflammation, and oxidative stress in Wistar rats, since these in vivo studies were crucial to understand the impact of developed delivery systems in the RA neuroprotective effects. The animals were treated through nasal route with RA CNE (2 mg·mL-1), free RA (2 mg·mL-1), blank CNE, and saline (control and LPS groups) administrations (n.a., 100 µL per nostril) twice a day (7 a.m./7 p.m.) for six days. On the sixth day, the animals received the last treatments and LPS was intraperitoneally (i.p.) administrated (250 µg·kg-1). Overall results, proved for the first time that the RA CNE nasal administration elicits a neuroprotective effect against LPS-induced damage, which was associated with increased 1.6 times recognition index, decreased 5.0 and 1.9 times in GFAP+ cell count and CD11b expression, respectively, as well as increased 1.7 times SH in cerebellum and decreased 3.9 times TBARS levels in cerebral cortex in comparison with LPS group. RA CNE treatment also facilitates RA bioavailability in the brain, confirmed by RA quantification. Free RA also demonstrates a protective effect in some studied parameters, although no RA was quantified in the brain.

Hydrogels containing soybean isoflavone aglycones-rich fraction-loaded nanoemulsions for wound healing treatment - in vitro and in vivo studies.

Soybean isoflavone aglycones have been investigated as potential wound healing compounds for topical application. The aim of this study was to evaluate the wound healing properties of a soybean isoflavone aglycones-rich fraction (IAF) when incorporated into lipid nanoemulsions dispersed in acrylic-acid hydrogels. Formulations exhibited a mean droplet size in the sub 200 nm range, negative ζ-potential (-60 mV), and displayed non-Newtonian pseudoplastic behavior. The addition of a gelling agent decreased the IAF release from formulations and improved the retention of these compounds in intact porcine ear skin when compared with a control propylene glycol solution. No IAF were detected in receptor fluid of Franz-type diffusion cells. However, increasing amounts of IAF were noticed in both skin layers and the receptor fluid when the tissue was partially injured (tape stripping), or when the epidermis was completely removed. In vitro studies showed that IAF elicits an increased proliferation and migration of keratinocytes (HaCaT cell line). Subsequently, the healing effect of the formulations was evaluated in a model of dorsal wounds in rats, by assessing the size of the lesions, histology, inflammatory markers, and antioxidant activity. Overall findings demonstrated the potential of IAF-loaded formulations to promote wound healing by increasing angiogenesis by ∼200 %, reducing the lipid oxidation (TBARS) by ∼52 % and the inflammation (TNFα) by ∼35 %, while increasing re-epithelialization by ∼500 %, visualized by the epithelium thickness.

A stability-indicating ultra-fast liquid chromatography method for the assay of the main flavonoids of Achyrocline satureioides (Marcela) in porcine skin layers and nanoemulsions.

INTRODUCTION: Achyrocline satureioides (marcela or macela) is a plant widely used in folk medicine in South America. Recently, there has been increasing interest for the development of skin care products containing A. satureoides extracts, due to its well-documented antioxidant, antiherpetic, and wound healing properties. OBJECTIVES: The present study aimed to develop and validate a yet unexplored stability-indicating and robust ultra-fast liquid chromatography (UFLC) method for the simultaneous quantification of the main flavonoids of A. satureioides in extracts, nanoemulsions, and porcine skin layers. MATERIAL AND METHODS: The chromatographic separation of flavonoids quercetin, luteolin, and 3-O-methylquercetin was performed on a Luna C18 analytical column (100 mm × 2.0 mm i.d.; particle size 2.5 µm) using isocratic elution with methanol/phosphoric acid 1% (48:52 v/v) with a flow rate of 0.3 mL/min at 40°C. RESULTS: The method was found to be specific, linear (R > 0.998), precise, accurate, and robust for all flavonoids assayed in A. satureioides extract, nanoemulsions, and porcine ear skin. A low matrix effect was noted for all complex matrices. The stability-indicating UFLC method was evaluated by submitting isolated flavonoids, a mixture of standards, and A. satureioides extract to acidic, alkaline, oxidative, UV-A/UV-C light, and thermal stress conditions. No peaks were found co-eluting with the flavonoids of interest in all matrices. The robustness of the method was confirmed using Plackett-Burman experimental design. CONCLUSION: The short run time (8 min) and reliability of the method could be useful for the determination of A. satureioides flavonoids in topical product development since extracts of this medicinal plant have been used to treat various skin disorders.

Glioprotective Effect of Chitosan-Coated Rosmarinic Acid Nanoemulsions Against Lipopolysaccharide-Induced Inflammation and Oxidative Stress in Rat Astrocyte Primary Cultures.

Rosmarinic acid (RA) is a natural polyphenolic compound with a well-documented neuroprotective effect mainly associated with its anti-inflammatory and antioxidant activities. Recently, our research group developed and optimized chitosan-coated RA nanoemulsions (RA CNE) intended to be used for nasal delivery as a new potential neuroprotective therapy. In this sense, the present study aimed to evaluate the protective and/or therapeutic potential of RA CNE in inflammation/oxidative stress induced by LPS (1 µg mL-1) in rat astrocyte primary cultures. In summary, pre-treatment with RA CNE before exposure to LPS (protective protocol) reduced significantly the LPS-induced alterations in astrocyte cell viability, proliferation, and cell death by necrosis, which was not observed in therapeutic protocol. RA CNE protective protocol also enhanced anti-oxidative status by ~ 50% by decreasing oxygen reactive species production and nitric oxide levels and preventing total thiol content decrease. Finally, our results demonstrate the protective effect of RA CNE in migratory activation and GFAP expression of reactive astrocytes. Overall, our findings indicate for the first time the RA CNE glioprotective potential, associated with an increase in cell viability and proliferation, a preventive effect on cellular death by necrosis, migratory ability and hypertrophic reactive astrocytes, and the reparation of astrocyte redox state.

Compatibility study of rosmarinic acid with excipients used in pharmaceutical solid dosage forms using thermal and non-thermal techniques.

Rosmarinic acid (RA) is a phenolic compound that presents well-documented anti-inflammatory, antioxidant and antitumor activities, and based on its pharmacological potential and poor bioavailability, several solid dosage forms have been developed to RA delivery. Therefore, in literature, there are no reports about RA compatibility with excipients. In this regard, the aim of the present study was to evaluate, for the first time, the compatibility of RA with excipients commonly used in solid dosage forms at a 1:1 (RA:excipient) ratio using differential scanning calorimetry (DSC), thermogravimetry (TG), Fourier-transform infrared (FTIR), solid-state nuclear magnetic resonance (ssNMR), and isothermal stress testing (IST) coupled with liquid chromatography (LC). The excipients selected were hydroxypropyl methylcellulose (HPMC), microcrystalline cellulose (MCC), lactose monohydrate (LAC), polyvinylpyrrolidone (PVP), talc (TALC), croscarmellose sodium (CCS), and magnesium stearate (MgSTE). According to DSC results, physical interactions were found between RA and HPMC, LAC, CCS, and MgSTE. The TG analyses confirmed the physical interactions and suggested chemical incompatibility. FTIR revealed physical interaction of RA with TALC and MgSTE and the ssNMR confirmed the physical interaction showed by FTIR and excluded the presence of chemical incompatibility. By IST, the greatest loss of RA content was found to CCS and MgSTE (>15%), demonstrating chemical incompatibilities with RA. High temperatures used in DSC and TG analyses could be responsible for incompatibilities in binary mixtures (BMs) with HPMC and LAC, while temperature above 25 °C and presence of water were factors that promote incompatibilities in BMs with CCS and MgSTE. Overall results demonstrate that RA was compatible with MCC and PVP.

Development, physico-chemical characterization and in-vitro studies of hydrogels containing rosmarinic acid-loaded nanoemulsion for topical application.

OBJECTIVES: Natural sources with antioxidant activity, such as rosmarinic acid (RA), have been considered as an interesting approach for the development of new anti-ageing skin products. In this context, this study aimed to develop hydrogels containing RA-loaded nanoemulsions and evaluate the effect of the addition of Tween® 80 (a nonionic cosurfactant) in formulations intended to be used for topical application. METHODS: Physico-chemical characterization, in-vitro release and skin retention/permeation from hydrogels of RA-loaded nanoemulsions (containing or not Tween® 80) were evaluated. The RA-loaded nanoemulsion safety profiles were also investigated in keratinocytes (HaCaT cells). KEY FINDINGS: It was observed that all formulations presented adequate physico-chemical characterization for topical application. Furthermore, the results also demonstrated that the presence of Tween® 80 decreased the droplet size and polydispersity index of nanoemulsions and hydrogels. An extended RA release was noted for the hydrogels. However, when comparing the hydrogels, a positive effect of the presence of Tween® 80 on RA retention/permeation in total skin was seen. The RA-loaded nanoemulsion safety profiles demonstrated a good tolerability (3.125-100 µm) in HaCaT cells. CONCLUSIONS: The overall results demonstrated that the formulations developed in this study can be considered as a suitable carrier for RA in a topical application targeting new anti-ageing skin care products.

An overview of the neuroprotective potential of rosmarinic acid and its association with nanotechnology-based delivery systems: A novel approach to treating neurodegenerative disorders.

Neurodegenerative disorders (ND) are characterized by slow and progressive neuronal dysfunction induced by the degeneration of neuronal cells in the central nervous system (CNS). Recently, the neuroprotective effects of natural compounds with anti-inflammatory and antioxidant activities has been clearly demonstrated. This appears to be an attractive therapeutic approach for ND, particularly regarding the use of polyphenols. In this review, we present an overview of the neuroprotective potential of rosmarinic acid (RA) and discuss the use of nanotechnology as a novel approach to treating ND. RA presents a variety of biological important activities, i.e. the modulation of pro-inflammatory cytokine expression, prevention of neurodegeneration and damage reduction. However, its poor bioavailability represents a limitation in terms of pharmacodynamics. In this sense, nanotechnology-based carriers could allow for the administration of higher but still safe amounts of RA, aiming for CNS delivery. Nasal administration could be a pleasant route for delivery to the CNS, as this represents a direct route to the CNS. With these advantages, RA-loaded nanotechnology-based therapy through the nasal route could be promising approach for the treatment of ND.

Skin Permeation and Oxidative Protection Effect of Soybean Isoflavones from Topical Nanoemulsions-a Comparative Study of Extracts and Pure Compounds.

Soybean isoflavone-rich extracts have been considered as promising skin antiaging products due to their antioxidant activity. This study investigates the effect of soybean isoflavone forms on porcine ear skin permeation/retention from topical nanoemulsions and their potential in protecting skin against oxidative damage caused by UVA/UVB light. Soybean non-hydrolyzed (SNHE) and hydrolyzed (SHE) extracts, mainly composed of genistin and genistein, were produced. Nanoemulsions containing SNHE (NESNHE) and SHE (NESHE) were prepared by spontaneous emulsification procedure and yielded monodispersed nanoemulsions. A delay of isoflavone release was observed after extracts incorporation into nanoemulsions when compared to a propyleneglycol dispersion of pure compounds. An increase of isoflavone skin retention from nanoemulsions was also achieved. However, from extracts, a higher amount of genistin (NESNHE) and a lower amount of genistein (NESHE) were detected in the skin in comparison to pure isoflavones. Finally, the protection of porcine ear skin by formulations against UVA/UVB oxidative stress was evaluated. Extract-loaded nanoemulsions offered better skin protection than pure isoflavones. Skin lipids were similarly protected by NESHE and NESNHE, whereas skin proteins were more protected by NESNHE. Overall, nanoemulsions containing isoflavone-rich soybean extracts may be considered a better topical formulation aiming skin protection from UVA/UVB oxidative damage.

Box-Behnken design optimization of mucoadhesive chitosan-coated nanoemulsions for rosmarinic acid nasal delivery-In vitro studies.

Mucoadhesive chitosan-coated nanoemulsions for rosmarinic acid (RA) nasal delivery were optimized. The optimum ratio between the formulation components that led to minimum droplet size and PDI, and maximal ζ-potential and RA content was obtained using Box-Behnken design (BBD). Optimized conditions were 8.5% oil phase (w/v), 3:10 lecithin to oil phase ratio (w/w), and 0.1% chitosan final concentration (w/v). Physicochemical characterization, mucoadhesion measurement, in vitro release and permeation/retention were performed. Optimized chitosan-coated RA nanoemulsions presented adequate physicochemical characteristics, high mucoadhesive potential, prolonged drug release, and long-lasting permeation time with a higher RA penetration/retention through porcine nasal mucosa. Cell viability and death by necrosis in fibroblasts cells were also evaluated to investigate the formulations safety. Formulations did not induce cytotoxicity following 24 h (3.125-50 µM) or 48 h (3.125-25 µM) of treatments. Overall results demonstrated that optimized chitosan-coated nanoemulsion showed to be a suitable carrier for RA nasal delivery aiming neuroprotective therapies.