RESUMEN

Essential oils (EOs) are natural antioxidant alternatives that reduce skin damage. However, EOs are highly volatile; therefore, their nanoencapsulation represents a feasible alternative to increase their stability and favor their residence time on the skin to guarantee their effect. In this study, EOs of Rosmarinus officinalis and Lavandula dentata were nanoencapsulated and evaluated as skin delivery systems with potential antioxidant activity. The EOs were characterized and incorporated into polymeric nanocapsules (NC-EOs) using nanoprecipitation. The antioxidant activity was evaluated using the ferric thiocyanate method. The ex vivo effects on pig skin were evaluated based on biophysical parameters using bioengineering techniques. An ex vivo dermatokinetic evaluation on pig skin was performed using modified Franz cells and the tape-stripping technique. The results showed that the EOs had good antioxidant activity (>65%), which was maintained after nanoencapsulation and purification. The nanoencapsulation of the EOs favored its deposition in the stratum corneum compared to free EOs; the highest deposition rate was obtained for 1,8-cineole, a major component of L. dentata, at 1 h contact time, compared to R. officinalis with a major deposition of the camphor component. In conclusion, NC-EOs can be used as an alternative antioxidant for skin care.

Asunto(s)

Nanocápsulas , Aceites Volátiles , Animales , Porcinos , Aceites Volátiles/farmacología , Antioxidantes/farmacología , Piel , Eucaliptol , Polímeros

RESUMEN

Alopecia areata is managed with oral corticosteroids, which has known side effects for patients. Given that a topical application of formulations containing a corticoid and a substance controlling hair loss progression could reduce or eliminate such adverse effects and increase the patient's adherence to the treatment, this study prepares polymeric and lipidic nanoparticles (PNPs and NLCs) to co-entrap minoxidil and betamethasone and compares the follicular drug delivery provided by topical application of these nanoparticles. The prepared PNPs loaded 99.1 ± 13.0% minoxidil and 70.2 ± 12.8% betamethasone, while the NLCs entrapped 99.4 ± 0.1 minoxidil and 80.7 ± 0.1% betamethasone. PNPs and NLCs presented diameters in the same range, varying from 414 ± 10 nm to 567 ± 30 nm. The thermal analysis revealed that the production conditions favor the solubilization of the drugs in the nanoparticles, preserving their stability. In in vitro permeation studies with porcine skin, PNPs provided a 2.6-fold increase in minoxidil penetration into the follicular casts compared to the control and no remarkable difference in terms of betamethasone; in contrast, NLCs provided a significant (specifically, a tenfold) increase in minoxidil penetration into the hair follicles compared to the control, and they delivered higher concentrations of betamethasone in hair follicles than both PNPs and the control. Neither PNPs nor NLCs promoted transdermal permeation of the drugs to the receptor solution, which should favor a topical therapy. Furthermore, both nanoparticles targeted approximately 50% of minoxidil delivery to the follicular casts and NLCs targeted 74% of betamethasone delivery to the hair follicles. In conclusion, PNPs and NLCs are promising drug delivery systems for enhancing follicular targeting of drugs, but NLCs showed superior performance for lipophilic drugs.

RESUMEN

Liquid crystalline nanoparticles (LCNs) are an attractive drugs topical delivery system due to the great internal ordering, wide interfacial area and structural similarities with the skin. In this work, LCNs were designed to encapsulate triptolide (TP) and to complex on its surface small interfering RNAs (siRNA) targeting TNF-α and IL-6, aiming at topical co-delivery and regulating multi-targets in psoriasis. These multifunctional LCNs showed appropriate physicochemical properties for topical application, such as a mean size of 150 nm, low polydispersion, TP encapsulation greater than 90% and efficient complexation with siRNA. The internal reverse hexagonal mesostructure of LCNs was confirmed by SAXS while their morphology was assessed by cryo-TEM. In vitro permeation studies revealed an increase of more than 20-fold in the distribution of TP through the porcine epidermis/dermis was achieved after the application of LCN-TP or LCN TP in hydrogel. In cell culture, LCNs showed good compatibility and rapid internalization, which was attributed to macropinocytosis and caveolin-mediated endocytosis. Anti-inflammatory potential of multifunctional LCNs was assessed by reducing of TNF-α, IL-6, IL-1ß and TGF-ß1 levels in LPS-stimulated macrophages. These results support the hypothesis that the co-delivery of TP and siRNAs by LCNs may be a new strategy for psoriasis topical therapy.

Asunto(s)

Nanopartículas , Psoriasis , Porcinos , Animales , ARN Interferente Pequeño , Factor de Necrosis Tumoral alfa , Interleucina-6 , Dispersión del Ángulo Pequeño , Difracción de Rayos X , Psoriasis/tratamiento farmacológico , Nanopartículas/química

RESUMEN

Vitamins are widely found in nature, for example, in plants and fruits. Ascorbic acid and nicotinamide are examples of these compounds that have potent antioxidant properties, besides stimulating collagen production and depigmenting properties that protect the skin from premature aging. To overcome the skin barrier and reduce the instability of antioxidant compounds, alternative systems have been developed to facilitate the delivery of antioxidants, making them efficiently available to the tissue for an extended time without causing damage or toxicity. The objective of this study was to obtain chitosan biodegradable microparticles containing ascorbic acid and nicotinamide for topical delivery. The microparticles were obtained by spray drying and characterized chemically by means of scanning electron microscopy, infrared spectroscopy, X-ray diffraction, and differential exploratory calorimetry. The drugs were successfully encapsulated and the microparticles showed positive zeta potential. In vitro release assays showed a sustained release profile. The evaluation of ex vivo skin permeation and retention demonstrated low permeation and adequate retention of the compounds in the epidermis/dermis, suggesting the efficient delivery from the obtained microparticles. Antibacterial assays have shown that microparticles can inhibit the growth of microorganisms in a time- and dose-dependent manner, corroborating their use in cosmetic products for application on the skin.

RESUMEN

Thermosensitive bioadhesive formulations can display increased retention time, skin permeation, and improve the topical therapy of many drugs. Acne is an inflammatory process triggered by several factors like the proliferation of the bacteria Propionibacterium acnes. Aiming for a new alternative treatment with a natural source, propolis displays great potential due to its antibiotic, anti-inflammatory, and healing properties. This study describes the development of bioadhesive thermoresponsive platform with cellulose derivatives and poloxamer 407 for propolis skin delivery. Propolis ethanolic extract (PES) was added to the formulations with sodium carboxymethylcellulose (CMC) or hydroxypropyl methylcellulose (HPMC) and poloxamer 407 (Polox). The formulations were characterized as rheology, bioadhesion, and mechanical analysis. The selected formulations were investigated as in vitro propolis release, cytotoxicity, ex vivo skin permeation by Fourier Transform Infrared Photoacoustic Spectroscopy, and the activity against P. acnes. Formulations showed suitable sol-gel transition temperature, shear-thinning behavior, and texture profile. CMC presence decreased the cohesiveness and adhesiveness of formulations. Polox/HPMC/PES system displayed less cytotoxicity, modified propolis release governed by anomalous transport, skin permeation, and activity against P. acnes. These results indicate important advantages in the topical treatment of acne and suggest a potential formulation for clinical evaluation.

Asunto(s)

Acné Vulgar , Própolis , Acné Vulgar/tratamiento farmacológico , Celulosa , Geles/química , Humanos , Derivados de la Hipromelosa , Poloxámero/química

RESUMEN

Nanotechnology-based delivery systems have been considered a promising approach for topical application, considering their characteristics of penetration into/across the skin. The present review aimed to evaluate the recent international scenario of patents concerning the use of nanotechnology- based delivery systems as skin penetration enhancers. A survey of recent patent documents was conducted by using the Espacenet patent database including the terms "skin" in the title and "promot* or enhanc* and penetrat* or absorp* or permeat*" and "nano*" with the truncation symbol (*) in the abstract of documents. A total of 110 patents were published from 2008 to 2018, with 94 technologies being considered. The results demonstrated an increase in innovations concerning nanotechnologybased delivery systems as skin penetration enhancers in recent years. Most patent applicants are from China (60.6%) and Korea (21.3%), and companies (68%) were the most prominent owners. The majority of patent applications (76%) were intended for cosmetic purposes; the types of products and nanostructures were also investigated. Overall results demonstrated the increased interest around the world in patenting products involving skin permeation promotion and nanotechnology for pharmaceutical and, mainly, for cosmetics purposes.

Asunto(s)

Sistemas de Liberación de Medicamentos , Nanotecnología , Absorción Cutánea , Administración Cutánea , Cosméticos , Humanos , Nanoestructuras , Patentes como Asunto , Preparaciones Farmacéuticas/administración & dosificación , Preparaciones Farmacéuticas/metabolismo

RESUMEN

Organogels (ORGs) are semi-solid materials, in which an organic phase is immobilized by a three-dimensional network composed of self-organized system, forming the aqueous phase. In this context, lipid-Pluronics (PLs) ORGs form a two-phase system which can be effectively used as skin delivery systems, favoring their permeation across the skin. In this study, we presented the development of ORG skin drug-delivery systems for curcumin (CUR), a liposoluble phenolic pigment extracted from the turmeric rhizome. In special, we designed the formulation compositions in order to carry high amounts of CUR soluble in oleic acid (OA), as organic phase, entrapped into an aqueous phase composed of micellar PL-based hydrogels by associating two polymers with different hydrophilic-lipophilic balances, Pluronic F-127 (PL F-127), and Pluronic L-81 (PL L-81), to enhance the permeation across the skin. Results revealed that the incorporation of PL L-81 favored the CUR incorporation into micelle-micelle interface. CUR insertion into OA-PL F-127/L-81 reduced both G'/G" relationship (∼16 x) and viscosity values (η* ∼ 54 mPa.s, at 32.5°C), disturbing the ORG network structural organization. In vitro permeation assays through Strat-M® skin-model membranes showed that higher CUR-permeated amounts were obtained for OA-PL F-127/L-81 (4.83 µg.cm-2) compared to OA-PL F-127 (3.51 µg.cm-2) and OA (2.25 µg.cm-2) or hydrogels (∼1.2 µg.cm-2, p < 0.001). Additionally, ORG formulations presented low cytotoxic effects and evoked pronounced antileishmanial activity (IC50 < 1.25 µg.ml-1), suggesting their potential use as skin delivery systems against Leishmania amazonensis. Results from this study pointed out OA-PL-based ORGs as promising new formulations for possible CUR topical administration.

RESUMEN

Vaccination faces many challenges nowadays, and among them the use of adjuvant molecules and needle-free administration are some of the most demanding. The combination of transcutaneous vaccination and nanomedicine through a rationally designed new-formulation could be the solution to this problem. This study focuses on this rational design. For this purpose, new hyaluronic acid nanocapsules (HA-NCs) have been developed. This new formulation has an oily nucleus with immunoadjuvant properties (due to α tocopherol) and a shell made of hyaluronic acid (HA) and decorated with ovalbumin (OVA) as the model antigen. The resulting nanocapsules are smaller than 100 nm, have a negative superficial charge and have a population that is homogeneously distributed. The systems show high colloidal stability in storage and physiological conditions and high OVA association without losing their integrity. The elevated interaction of the novel formulation with the immune system was demonstrated through complement activation and macrophage viability studies. Ex vivo studies using a pig skin model show the ability of these novel nanocapsules to penetrate and retain OVA in higher quantities in skin when compared to this antigen in the control solution. Due to these findings, HA-NCs are an interesting platform for needle-free vaccination.

RESUMEN

The first limiting barrier for the transport in the skin is the stratum corneum; different strategies have been developed to overcome this barrier, including chemical enhancers. However, these penetration enhancers have limitations, including toxic adverse effects. In this context, research into nanomaterials has provided new tools to increase the residence time of drugs by generating a reservoir, increasing the specificity of drugs and reducing their adverse effects, and improving the penetration of drugs that are difficult to formulate. Silica nanoparticles have been proposed as suitable nanocarriers for skin delivery. Unfortunately, the mechanisms involved in the interaction, transport and fate of silica nanoparticles in the skin have not been fully investigated. This paper reviews significant findings about the interaction between silica-based nanocarriers and the skin. First, this review focuses on the properties and functions of the skin, the skin penetration properties of silica nanoparticles, their synthesis strategies and their toxicity. Finally, advances and evidence on the application of silica nanocarriers in skin drug delivery are provided, in which the use of nanoparticles increases the stability and solubility of the bioactive compound, enhancing its performance, act as penetrator enhancer and improving controlled release. Thus, improving the treatment of some skin disorders.

Asunto(s)

Sistemas de Liberación de Medicamentos , Nanopartículas/administración & dosificación , Dióxido de Silicio/administración & dosificación , Absorción Cutánea , Piel/efectos de los fármacos , Administración Cutánea , Animales , Portadores de Fármacos , Humanos

RESUMEN

Novel protamine-based nanosystems have been studied for cyclosporine-A (CsA) skin delivery. Core-shell structure systems have been developed to this end. These vehicles have particles sizes of 200-300 nm, a low polydispersity index and a zeta potential which varies between -16 mV and +35 mV. The resulting four nanosystems efficiently encapsulated CsA in their oily nucleus (60-80%) and released this drug in a controlled manner. These formulations have shown a high stability in aqueous suspension in storage conditions at 4 °C (for at least 21 months) and in acetate buffer at a physiological temperature of 37 °C (for at least 24 h). Ex vivo transdermal diffusion experiments using Franz diffusion cells and 2- to 3-day-old pig skin as a biological barrier were performed. All nanoformulations designed produced an increase in CsA transdermal delivery and two of these nanosystems presented a marked promoting effect; the more relevant parameters were smaller particle size (200 ± 7 nm) and negative superficial charge. Finally, the ability of these nanosystems to enhance retention of CsA in the skin was also studied. The protamine disposition in the shell influenced CsA skin retention. Therefore, the incorporation of CsA into the nanosystems studied here makes them suitable vehicles for CsA transdermal administration.

Asunto(s)

Ciclosporina/administración & dosificación , Ciclosporina/farmacocinética , Fármacos Dermatológicos/administración & dosificación , Fármacos Dermatológicos/farmacocinética , Nanocápsulas/química , Protaminas/química , Absorción Cutánea , Administración Cutánea , Animales , Ciclosporina/química , Fármacos Dermatológicos/química , Emulsiones/química , Tamaño de la Partícula , Piel/metabolismo , Porcinos

RESUMEN

Ultradeformable liposomes (UDLs) containing sodium cholate as edge activator could be an appropriate skin drug-delivery system for chloroaluminum phthalocyanine (ClAlPc) during photodynamic therapy (PDT) against cutaneous leishmaniasis (CL). The aim of this work was to study cell internalization, reactive oxygen species (ROS) production, and toxicity/genotoxicity and transdermal delivery of UDL-ClAlPc, and to determine whether PDT was able to induce anti-leishmanial activity in Leishmania (Viannia) braziliensis experimental models. Prepared liposomes had an average size of 118.39 nm, zeta potential of -37.83 mV, and polydispersity index of 0.15. Liposomal internalization (red fluorescence inside cells), ROS generation (green fluorescence by 2,7-dichlorodihydrofluorescein diacetate [DCFH-DA] cleavage) and non-specific DNA damage (photo-comets) were observed after PDT. Transdermal delivery of ClAlPc, measured by in vitro diffusion experiments through BALB/c skin, showed that UDL-ClAlPc was able to deliver very low quantities of ClAlPc (<1%) to deep skin layers. PDT using UDL-ClAlPc induced photodamage in mammalian cells (J774, THP-1, and NIH-3T3), promastigotes, and intracellular amastigotes without a selective response against amastigotes (selective index ≥1). Topical once-daily ClAlPc-UDL plus visible-light irradiation (20 J/cm2) twice weekly for 3 weeks was ineffective against L. (V.) braziliensis-infected BALB/c mice, whereas miltefosine 30 mg/kg/day orally for 10 days healed the lesions and scars, without parasites observed on the slides. Even though UDLs preserved ClAlPc photoactivities and were able to deliver ClAlPc to dermis, they were unable to result in healing of CL-infected mice after PDT. Experiments using different CL animal models and liposomes with increased skin permeability abilities are recommended.

Asunto(s)

Indoles/administración & dosificación , Leishmania braziliensis/efectos de los fármacos , Leishmaniasis Cutánea/tratamiento farmacológico , Compuestos Organometálicos/administración & dosificación , Fotoquimioterapia/métodos , Animales , Línea Celular , Daño del ADN , Femenino , Concentración 50 Inhibidora , Liposomas , Ratones , Ratones Endogámicos BALB C , Especies Reactivas de Oxígeno/metabolismo

RESUMEN

This study aimed to develop gel-creams from the lyophilised product of betamethasone dipropionate-loaded lipid-core nanocapsule suspensions and evaluated its efficacy in a model of contact dermatitis. The gel-creams were prepared and characterized followed by a study of in vitro drug penetration/permeation and its in vivo efficacy. The suspensions and lyophilised products showed nanometric size; the betamethasone content was 0.25 ± 0.01 mg/mL and the encapsulation efficiency was approximately 100%. The nanocapsules and redispersed powders presented control of the drug release. The gel-creams presented pH between 6.0-6.5 and exhibited non-Newtonian flow behavior, following the Herschel-Bulkley model. The skin penetration/permeation study indicated that betamethasone dipropionate can reach different skin layers. For in vivo efficacy, the contact dermatitis model was capable of causing tissue damage with changes in enzyme activities of the purinergic system in lymphocytes. The gel-creams showed the best dermatological and immunological efficacy and reduced oxidative damage in the evaluated tissues.

RESUMEN

Topical drug delivery is an interesting approach to treat skin diseases and to avoid pain and low patient compliance in cases where a systemic delivery is required. However, the stratum corneum, which is the outermost skin layer, strongly protects the body from the entrance of substances, especially those hydrophilic. In this context, different physical methods have been studied to overcome the stratum corneum barrier and facilitate penetration of drugs into or through the skin. Among them, iontophoresis, low-frequency ultrasound and microneedles have been widely employed for transdermal drug delivery. More recently, they are also studied to aid in the treatment of dermatological disorders, such as skin tumors and inflammation. Basically, iontophoresis refers to the movement of charged and non-charged hydrophilic molecules through the skin due to the application of a low constant electric current and the contributions of electromigration and electroosmosis. In low-frequency ultrasound, cavitation is the main mechanism for skin permeabilization that consists on the formation of microbubbles that disorganize the stratum corneum. Microneedles are microprojections, minimally invasive, that can be designed with different lengths, materials and geometry to increase skin permeability. In this review, concepts, mechanisms and applications of these three physical methods will be presented and discussed with focus on their use in dermatological treatments. Moreover, comparative studies using different physical methods will be presented and also some clinical perspectives will be addressed

Asunto(s)

Piel , Administración Tópica , Enfermedades de la Piel/tratamiento farmacológico , Ultrasonido/métodos , Administración Cutánea , Iontoforesis/métodos

RESUMEN

Aiming to improve the topical delivery of AmB to treat cutaneous fungal infections and leishmaniasis, ultradeformable liposomes containing amphotericin B (AmB-UDL) were prepared, and structural and functional characterized. The effect of different edge activators, phospholipid and AmB concentration, and phospholipid to edge activator ratio on liposomal deformability, as well as on AmB liposomal content, was tested. Liposomes having Tween 80 as edge activator resulted of maximal deformability and AmB/phospholipid ratio. These consisted of AmB-UDL of 107±8nm diameter, 0.078-polydispersity index and -3±0.2mV Z potential, exhibiting monomeric AmB encapsulated in the bilayer at a 75% encapsulation efficiency. After its cytotoxicity on keratinocytes (HaCaT cells) and macrophages (J774 cells) was determined, the in vitro antifungal activity of AmB-UDL was assayed. It was found that fungal strains (albicans and non-albicans Candida ATCC strains and clinical isolates of C. albicans) were more sensitive to AmB-UDL than mammal cells. Minimum inhibitory concentration values for AmB-UDL were 5-24 and 24-50 times lower than IC50 for J774 and HaCaT cells, respectively. AmB-UDL at 1.25µg/ml also displayed 100 and 75% anti- Leishmania braziliensis promastigote and amastigote activity, respectively. Finally, upon 1h of non-occlusive incubation, the total accumulation of AmB in human skin was 40 times higher when applied as AmB-UDL than as AmBisome. AmB-UDL provided a profound AmB penetration toward deep epithelial layers, achieved without classical permeation enhancers. Because of that, topical treatments of cutaneous fungal infection and leishmaniasis with AmB-UDL may be regarded of potential of clinical significance.

Asunto(s)

Anfotericina B/farmacología , Antifúngicos/farmacología , Antiprotozoarios/farmacología , Liposomas/química , Absorción Cutánea , Anfotericina B/química , Anfotericina B/farmacocinética , Animales , Antifúngicos/química , Antifúngicos/farmacocinética , Antiprotozoarios/química , Antiprotozoarios/farmacocinética , Candida albicans/efectos de los fármacos , Candida albicans/crecimiento & desarrollo , Línea Celular Transformada , Línea Celular Tumoral , Composición de Medicamentos , Humanos , Concentración 50 Inhibidora , Queratinocitos/efectos de los fármacos , Queratinocitos/microbiología , Queratinocitos/parasitología , Leishmania braziliensis/efectos de los fármacos , Leishmania braziliensis/crecimiento & desarrollo , Macrófagos/efectos de los fármacos , Macrófagos/microbiología , Macrófagos/parasitología , Ratones , Pruebas de Sensibilidad Microbiana , Tamaño de la Partícula , Polisorbatos/química , Piel/efectos de los fármacos , Piel/microbiología , Piel/parasitología , Electricidad Estática

RESUMEN

ABSTRACT Liquid-Crystalline Systems represent active compounds delivery systems that may be able to overcome the physical barrier of the skin, especially represented by the stratum corneum. To obtain these systems, aqueous and oily components are used with surfactants. Of the different association structures in such systems, the liquid-crystalline offer numerous advantages to a topical product. This manuscript presents the development of liquid-crystalline systems consisting, in which the oil component is olive oil, its rheological characterizations, and the location of liquid crystals in its phase map. Cytotoxic effects were evaluated using J-774 mouse macrophages as the cellular model. A phase diagram to mix three components with different proportions was constructed. Two liquid crystalline areas were found with olive oil in different regions in the ternary diagram with two nonionic surfactants, called SLC1 (S1) and SLC2 (S2). These systems showed lamellar liquid crystals that remained stable during the entire analysis time. The systems were also characterized rheologically with pseudoplastic behavior without thixotropy. The texture and bioadhesion assays showed that formulations were similar statistically (p < 0.05), indicating that the increased amount of water in S2 did not interfere with the bioadhesive properties of the systems. In vitro cytotoxic assays showed that formulations did not present cytotoxicity. Olive oil-based systems may be a promising platform for skin delivery of drugs.

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RESUMO Os cristais líquidos representam um sistema de liberação de substâncias ativas capazes de vencer a barreira cutânea, representada especialmente pelo estrato córneo. Água, óleo e tensoativos são misturados para se obter esses sistemas. Diferentes estruturas podem ser formadas nesses sistemas, as quais oferecem muitas vantagens para os produtos de uso tópico. Esse trabalho visou ao desenvolvimento de sistemas líquido-cristalinos preparados com óleo de oliva, sua caracterização reológica e a identificação das fases cristalinas no diagrama ternário. Efeitos citotóxicos foram avaliados usando células de rato como modelo celular. Construiu-se um diagrama de fases que mistura três componentes em diferentes proporções. Duas áreas de cristal líquido, denominadas SLC1 (S1) e SLC2 (S2), foram encontradas com óleo de oliva em diferentes regiões no diagrama ternário preparado com dois diferentes tensoativos não-iônicos. Esses sistemas mostraram fase cristalina lamelar, que permaneceu estável durante o tempo estudado. Os sistemas foram também caracterizados reologicamente e apresentaram comportamento pseudoplástico com tixotropia. Os ensaios de textura e bioadesão mostraram que as formulações foram similares (p < 0.05), indicando que o aumento da quantidade de água em S2 não interferiu nas propriedades bioadesivas dos sistemas. Os ensaios de citotoxicidade mostraram que as formulações não foram citotóxicas. Sistemas à base de óleo de oliva são interessantes para a liberação de fármacos na pele.

Asunto(s)

Nanotecnología/métodos , Aceite de Oliva/uso terapéutico , Reología/clasificación , Cristales Líquidos/análisis , Liberación de Fármacos

RESUMEN

Retinoids are lipophilic compounds that are highly used in cosmetics/therapeutics for skin disorders. Conventional formulations are limited by poor water solubility, high chemical/photochemical instability and the irritation of retinoids. Interestingly, lipid nanoparticles enable the administration of retinoids in aqueous media, providing drug stabilization and controlled release. Recently, it has been demonstrated that retinoids in solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions and nanocapsules can decrease degradation, improve targeting and enhance efficacy for the treatment of skin disorders. This article focuses on the formulation, fabrication, characterization and in vitro/in vivo evaluation of solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions and nanocapsules loaded with retinoids for skin administration. Furthermore, the incorporation of these lipid nanoparticles into secondary vehicles is discussed.

Asunto(s)

Lípidos/química , Nanopartículas/química , Retinoides/administración & dosificación , Retinoides/química , Administración Cutánea , Animales , Humanos , Piel/metabolismo , Absorción Cutánea

RESUMEN

Topical glucocorticoids (TG) such as dexamethasone (DEX) have been used for decades for the treatment of skin diseases. However, TG present well-documented side effects and their delivery to the skin is often insufficient. Therefore, many efforts have been undergone to improve the amount of drug delivered to the skin and to reduce side effects at the same time. In this work, the feasibility of DEX-submicron polymeric particles (SP) prepared by vibrational spray-drying as an approach to overcome the challenges associated with the topical administration of this drug class was evaluated. DEX was homogeneously dispersed in the SP matrix, according to confocal Raman microscopy analysis. Drug-loaded SP were incorporated into the oil phase of oil-in-water emulsions (creams). The formulation containing polymeric submicron particles (C-SP) showed controlled drug release kinetics and a significant drug accumulation in skin compared to formulations containing non-polymeric particles or free drug. DEX accumulation in the stratum corneum was evaluated by tape stripping and a depot effect over time was observed for C-SP, while the formulation containing the free drug showed a decrease over time. Similarly, C-SP presented higher drug retention in epidermis and dermis in skin penetration studies performed on pig skin in Franz diffusion cells, while drug permeation into the receptor compartment was negligible. It was demonstrated, for the first time, the advantageous application of submicron polymeric particles obtained by vibrational spray-drying in semisolid formulations for cutaneous administration to overcome challenges related to the therapy with TG such as DEX.

Asunto(s)

Dexametasona/administración & dosificación , Portadores de Fármacos/química , Glucocorticoides/administración & dosificación , Polímeros/química , Absorción Cutánea , Piel/metabolismo , Animales , Dexametasona/farmacocinética , Composición de Medicamentos/métodos , Liberación de Fármacos , Emulsiones , Glucocorticoides/farmacocinética , Técnicas In Vitro , Microscopía Confocal , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Piel/efectos de los fármacos , Propiedades de Superficie , Sus scrofa , Distribución Tisular , Vibración