RESUMO
As a new strategy for treatment of ductal carcinoma in situ, biocompatible and bioadhesive nanoemulsions for intraductal administration of the cytotoxic agent piplartine (piperlongumine) were optimized in this study. To confer bioadhesive properties, the nanoemulsion was modified with chitosan or hyaluronic acid. Tricaprylin was selected as the nanoemulsion non-polar phase due to its ability to dissolve larger drug amounts compared to isopropyl myristate and monocaprylin. Use of phosphatidylcholine as sole surfactant did not result in a homogeneous nanoemulsion, while its association with polysorbate 80 and glycerol (in a surfactant blend) led to the formation of nanoemulsions with droplet size of 76.5⯱â¯1.2â¯nm. Heating the aqueous phase to 50⯰C enabled sonication time reduction from 20 to 10â¯min. Inclusion of either chitosan or hyaluronic acid resulted in nanoemulsions with similar in vitro bioadhesive potential, and comparable ability to prolong mammary tissue retention (to 120â¯h) in vivo without causing undesirable histological alterations. Piplartine was stable in both nanoemulsions for 60â¯days; however, the size of loaded NE-HA was maintained at a similar range for longer periods of time, suggesting that this nanoemulsion may be a stronger candidate for intraductal delivery.
Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Dioxolanos/administração & dosagem , Glândulas Mamárias Animais/metabolismo , Nanopartículas/administração & dosagem , Piperidonas/administração & dosagem , Adesividade , Animais , Antineoplásicos Fitogênicos/química , Galinhas , Quitosana/administração & dosagem , Quitosana/química , Membrana Corioalantoide/efeitos dos fármacos , Dioxolanos/química , Vias de Administração de Medicamentos , Emulsões , Feminino , Glicerol/administração & dosagem , Glicerol/química , Ácido Hialurônico/administração & dosagem , Ácido Hialurônico/química , Nanopartículas/química , Fosfatidilcolinas/administração & dosagem , Fosfatidilcolinas/química , Piperidonas/química , Polissorbatos/administração & dosagem , Polissorbatos/química , Ratos Wistar , Pele/química , SuínosRESUMO
This study reports the development of a simple and reproducible method, with high rates of recovery, to extract the cytotoxic agent piplartine from skin layers, and a sensitive and rapid UV-HPLC method for its quantification. Considering the potential of piplartine for topical treatment of skin cancer, this method may find application for formulation development and pharmacokinetics studies to assess cutaneous bioavailability. Porcine skin was employed as a model for human tissue. Piplartine was extracted from the stratum corneum (SC) and remaining viable skin layers (VS) using methanol, vortex homogenization and bath sonication, and subsequently assayed by HPLC using a C18 column, and 1:1 (v/v) acetonitrile-water (adjusted to pH 4.0 with acetic acid 0.1%) as mobile phase. The quantification limit of piplartine was 0.2 µg/mL (0.6 µm), and the assay was linear up to 5 µg/mL (15.8 µm), with within-day and between-days assay coefficients of variation and relative errors <15%. Piplartine recovery from SC and VS varied from 86 to 96%. The method was suitable to assay samples from skin penetration studies, enabling detection of differences in cutaneous delivery in different skin compartments resulting from treatment with various formulations and time periods.
Assuntos
Antineoplásicos Fitogênicos/análise , Dioxolanos/análise , Piperidonas/análise , Pele/química , Animais , Antineoplásicos Fitogênicos/farmacocinética , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Dioxolanos/farmacocinética , Modelos Lineares , Piperidonas/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Pele/metabolismo , Absorção Cutânea , SuínosRESUMO
Considering that breast cancer usually begins in the lining of the ducts, local drug administration into the ducts could target cancers and pre-tumor lesions locally while reducing systemic adverse effects. In this study, a cationic bioadhesive nanoemulsion was developed for intraductal administration of C6 ceramide, a sphingolipid that mediates apoptotic and non-apoptotic cell death. Bioadhesive properties were obtained by surface modification with chitosan. The optimized nanoemulsion displayed size of 46.3 nm and positive charge, properties that were not affected by ceramide encapsulation (0.4%, w/w). C6 ceramide concentration necessary to reduce MCF-7 cells viability to 50% (EC50) decreased by 4.5-fold with its nanoencapsulation compared to its solution; a further decrease (2.6-fold) was observed when tributyrin (a pro-drug of butyric acid) was part of the oil phase of the nanocarrier, a phenomenon attributed to synergism. The unloaded nanocarrier was considered safe, as indicated by a score <0.1 in HET-CAM models, by the high survival rates of Galleria mellonella larvae exposed to concentrations ≤500 mg/mL, and absence of histological changes when intraductally administered in rats. Intraductal administration of the nanoemulsion prolonged drug localization for more than 120 h in the mammary tissue compared to its solution. These results support the advantage of the optimized nanoemulsion to enable mammary tissue localization of C6 ceramide.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Carcinoma Intraductal não Infiltrante/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/administração & dosagem , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/metabolismo , Carcinoma Intraductal não Infiltrante/patologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Galinhas , Emulsões , Feminino , Humanos , Células MCF-7 , Nanopartículas/metabolismo , Ratos , Resultado do TratamentoRESUMO
Because P-glycoprotein (P-gp) plays an absorptive role in the skin, its pharmacological inhibition represents a strategy to promote cutaneous localization of anticancer agents that serve as its substrates, improving local efficacy while reducing systemic exposure. Here, we evaluated the ability of a nanoemulsion (NE) coencapsulating a P-gp inhibitor (elacridar) with the antitumor drug paclitaxel to promote epidermal targeting. Loaded NE displayed a nanometric size (45.2 ± 4.0 nm) and negative zeta potential (-4.2 ± 0.8 mV). Elacridar improved NE ability to inhibit verapamil-induced ATPase activity of P-gp; unloaded NE-inhibited P-gp when used at a concentration of 1500 µM, while elacridar encapsulation decreased this concentration by 3-fold (p <0.05). Elacridar-loaded NE reduced paclitaxel penetration into the dermis of freshly excised mice skin and its percutaneous permeation by 1.5- and 1.7-fold (p <0.05), respectively at 6 h, whereas larger drug amounts (1.4-fold, p <0.05) were obtained in viable epidermis. Assessment of cutaneous distribution of a fluorescent paclitaxel derivative confirmed the smaller delivery into the dermis at elacridar presence. In conclusion, we have provided novel evidence that NE containing elacridar exhibited a clear potential for P-gp inhibition and enabled epidermal targeting of paclitaxel, which in turn, can potentially reduce adverse effects associated with systemic exposure to anticancer therapy.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Acridinas/farmacologia , Antineoplásicos/farmacologia , Portadores de Fármacos/química , Proteínas de Membrana Transportadoras/metabolismo , Nanopartículas/química , Pele/efeitos dos fármacos , Tetra-Hidroisoquinolinas/farmacologia , Acridinas/química , Administração Cutânea , Animais , Antineoplásicos/química , Transporte Biológico/efeitos dos fármacos , Emulsões/química , Emulsões/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Paclitaxel/química , Paclitaxel/farmacologia , Tamanho da Partícula , Tetra-Hidroisoquinolinas/química , Verapamil/química , Verapamil/farmacologiaRESUMO
Considering that tumor development is generally multifactorial, therapy with a combination of agents capable of potentiating cytotoxic effects is promising. In this study, we co-encapsulated C6 ceramide (0.35%) and paclitaxel (0.50%) in micro and nanoemulsions containing tributyrin (a butyric acid pro-drug included for potentiation of cytotoxicity), and compared their ability to co-localize the drugs in viable skin layers. The nanoemulsion delivered 2- and 2.4-fold more paclitaxel into viable skin layers of porcine skin in vitro at 4 and 8h post-application than the microemulsion, and 1.9-fold more C6 ceramide at 8h. The drugs were co-localized mainly in the epidermis, suggesting the nanoemulsion ability for a targeted delivery. Based on this result, the nanoemulsion was selected for evaluation of the nanocarrier-mediated cytotoxicity against cells in culture (2D model) and histological changes in a 3D melanoma model. Encapsulation of the drugs individually decreased the concentration necessary to reduce melanoma cells viability to 50% (EC50) by approximately 4- (paclitaxel) and 13-fold (ceramide), demonstrating an improved nanoemulsion-mediated drug delivery. Co-encapsulation of paclitaxel and ceramide further decreased EC50 by 2.5-4.5-fold, and calculation of the combination index indicated a synergistic effect. Nanoemulsion topical administration on 3D bioengineered melanoma models for 48h promoted marked epidermis destruction, with only few cells remaining in this layer. This result demonstrates the efficacy of the nanoemulsion, but also suggests non-selective cytotoxic effects, which highlights the importance of localizing the drugs within cutaneous layers where the lesions develop to avoid adverse effects.
Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Ceramidas/administração & dosagem , Portadores de Fármacos/administração & dosagem , Nanopartículas/administração & dosagem , Paclitaxel/administração & dosagem , Triglicerídeos/administração & dosagem , Animais , Antineoplásicos Fitogênicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ceramidas/química , Portadores de Fármacos/química , Emulsões , Melanoma/tratamento farmacológico , Nanopartículas/química , Paclitaxel/química , Pele/metabolismo , Absorção Cutânea/efeitos dos fármacos , Suínos , Triglicerídeos/químicaRESUMO
In this study, non-aqueous microemulsions were developed because of the challenges associated with finding pharmaceutically acceptable solvents for topical delivery of drugs sparingly soluble in water. The formulation irritation potential and ability to modulate the penetration of lipophilic compounds (progesterone, α-tocopherol, and lycopene) of interest for topical treatment/prevention of skin disorders were evaluated and compared to solutions and aqueous microemulsions of similar composition. The microemulsions (ME) were developed with BRIJ, vitamin E-TPGS, and ethanol as surfactant-co-surfactant blend and tributyrin, isopropyl myristate, and oleic acid as oil phase. As polar phase, propylene glycol (MEPG) or water (MEW) was used (26% w/w). The microemulsions were isotropic and based on viscosity and conductivity assessment, bicontinuous. Compared to drug solutions in lipophilic vehicles, MEPG improved drug delivery into viable skin layers by 2.5-38-fold; the magnitude of penetration enhancement mediated by MEPG into viable skin increased with drug lipophilicity, even though the absolute amount of drug delivered decreased. Delivery of progesterone and tocopherol, but not lycopene (the most lipophilic compound), increased up to 2.5-fold with MEW, and higher amounts of these two drugs were released from MEW (2-2.5-fold). Both microemulsions were considered safe for topical application, but MEPG-mediated decrease in the viability of reconstructed epidermis was more pronounced, suggesting its higher potential for irritation. We conclude that MEPG is a safe and suitable nanocarrier to deliver a variety of lipophilic drugs into viable skin layers, but the use of MEW might be more advantageous for drugs in the lower range of lipophilicity.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Absorção Cutânea/efeitos dos fármacos , Tensoativos/administração & dosagem , Administração Cutânea , Administração Tópica , Animais , Carotenoides/administração & dosagem , Carotenoides/metabolismo , Emulsões/administração & dosagem , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/fisiologia , Lipídeos/administração & dosagem , Licopeno , Propilenoglicol/administração & dosagem , Propilenoglicol/metabolismo , Pele/metabolismo , Absorção Cutânea/fisiologia , Tensoativos/metabolismo , Suínos , Viscosidade , alfa-Tocoferol/administração & dosagem , alfa-Tocoferol/metabolismoRESUMO
The skin presents several advantages as an administration route, including the possibility of localizing drugs in the tissue and overcoming the first-pass effect. However, its use is limited by the barrier function of the tissue, which is provided mainly (but not exclusively) by the stratum corneum. Various strategies to overcome this layer, have been considered over the years, ranging from the use of physical methods such as iontophoresis to wellknown conventional chemical penetration enhancers like oleic acid and DMSO. However, delivery of hydrophilic and large compounds remains a challenge. More recently, selected groups of peptides have attracted increasing attention due to their ability to penetrate into the skin promoting the transport of small and large molecules, including nanodispersed systems. Here, we will discuss the properties and application to cutaneous (into the skin) and transdermal (across the skin) delivery of three groups of peptides, namely protein-transduction domains, phage-displayed peptides and antimicrobial peptides.