RESUMO
The aim of this study was to propose the use of spray-dried mucoadhesive carvedilol-loaded nanocapsules in the formulation of sublingual tablets. There is no previous report describing the preparation of tablets containing spray-dried nanocapsules or tablets containing nanocapsules, neither prepared by direct compression nor for sublingual administration. Tablets of 6 mm of diameter and 2.7 ± 0.2 mm of height were obtained with a mean weight of 44 ± 4 mg, carvedilol content of 0.164 ± 0.017 mg, and a disintegration time less than 25 min. They were produced using a force of 4.7 ± 1.6 kgf. The release profile of carvedilol from the tablets was evaluated using the dialysis bag method. In parallel, the release of nanocapsules from the tablet structure into the release medium was evaluated using dynamic light scattering. Nanocapsules that were released from the tablets into the release medium exhibited similar particle size distributions after recovery as in their original liquid suspension, without losing their original ability to control drug release. Therefore, sublingual tablets may be produced from spray-dried drug-loaded nanocapsules using a direct compression technique, providing a useful pharmaceutical approach for drugs that undergo first pass metabolism, such as carvedilol.
Assuntos
Carvedilol/química , Nanocápsulas/química , Comprimidos/química , Administração Sublingual , Química Farmacêutica/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Nanomedicina/métodos , Tamanho da Partícula , Polímeros/química , Suspensões/químicaRESUMO
Cervical cancer is associated with the human papilloma virus (HPV) and nowadays is the fourth most frequent cancer among women. One of the treatments for this disease is based on the application of imiquimod. In this study, we postulated that the use of imiquimod in nanoemulsion results in a better antitumoral effect than the drug administered in its nonencapsulated form for the treatment of cervical cancer. Permeability studies using vaginal mucosa, as membrane, and in vitro studies involving cervical cancer cells (viability, clonogenic assay, and cell death analysis) were performed. We showed that low amount of encapsulated imiquimod permeated the vaginal mucosa. However, a higher percentage of cells died after the treatment with low amount (3.0 µmol L-1) of the formulation compared to the free drug. In addition, the innovative formulation presented a combinatory mechanism of cell death involving autophagy and apoptosis. Our results demonstrate that the imiquimod-loaded nanoemulsioncan be an alternative product for the treatment of cervical cancer validating the hypothesis.
Assuntos
Imiquimode/administração & dosagem , Papillomaviridae/efeitos dos fármacos , Neoplasias do Colo do Útero/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Composição de Medicamentos , Emulsões , Feminino , Humanos , Nanopartículas , Suínos , Neoplasias do Colo do Útero/virologiaRESUMO
This study aimed to evaluate in vitro and in vivo trypanocidal activity of free and nanoencapsulated curcumin against Trypanosoma evansi. In vitro efficacy of free curcumin (CURC) and curcumin-loaded in lipid-core nanocapsules (C-LNCs) was evaluated to verify their lethal effect on T. evansi. To perform the in vivo tests, T. evansi-infected animals were treated with CURC (10 and 100 mg kg(-1), intraperitoneally [i.p.]) and C-LNCs (10 mg kg(-1), i.p.) during 6 days, with the results showing that these treatments significantly attenuated the parasitaemia. Infected untreated rats showed protein peroxidation and an increase of nitrites/nitrates, whereas animals treated with curcumin showed a reduction on these variables. As a result, the activity of antioxidant enzymes (superoxide dismutase and catalase) differs between groups (P<0.05). Infected animals and treated with CURC exhibited a reduction in the levels of alanine aminotransferase and creatinine, when compared with the positive control group. The use of curcumin in vitro resulted in a better parasitaemia control, an antioxidant activity and a protective effect on liver and kidney functions of T. evansi-infected adult male Wistar rats.
Assuntos
Curcumina/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma/efeitos dos fármacos , Tripanossomíase/tratamento farmacológico , Produtos da Oxidação Avançada de Proteínas/sangue , Alanina Transaminase/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Catalase/sangue , Creatinina/metabolismo , Curcumina/administração & dosagem , Cães , Concentração de Íons de Hidrogênio , Rim/parasitologia , Rim/patologia , Rim/fisiopatologia , Fígado/enzimologia , Fígado/parasitologia , Fígado/patologia , Masculino , Nanocápsulas , Nitratos/sangue , Nitritos/sangue , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Ratos , Ratos Wistar , Superóxido Dismutase/sangue , Tripanossomicidas/administração & dosagem , Tripanossomíase/patologiaRESUMO
The oxidizing capacity and skin penetration of a commercial nanosized ZnO, Nanosun™ (Micronisers-Australia), were evaluated in vitro using porcine skin. Nanosun™ was initially characterized regarding its photo-reactivity and size distribution. An assay using methylene blue was performed to confirm the Nanosun™ photo-reactivity by exposing the labile molecule to UVA irradiation in the presence and absence of the nanosized ZnO. The nanosized ZnO was photo-reactive, reducing the methylene blue concentration to 7% while its concentration remained constant in the control formulation (without ZnO). The product label states that the average particle size is 30 nm. X-ray diffraction, nitrogen sorption and UV-spectrophotometry confirmed the presence of nanometric particles of approximately 30 nm. On the other hand, laser diffractometry showed micrometric particles in the size distribution profile. These analyses indicated that the nanoparticles are arranged as agglomerates and aggregates of micrometric proportions ranging from 0.6 to 60 µm. The skin lipid peroxidation was determined by the formation of thiobarbituric acid reactive species (TBARS) and quantified by UV-spectrophotometry. When exposed to UVA radiation the nanosized ZnO applied porcine skin showed a lower production of TBARS (7.2 ± 1.5 nmol g(-1)) than the controls, the MCT applied porcine skin (18.4 ± 2.8 nmol g(-1)) and the blank porcine skin (14.0 ± 2.0 nmol g(-1)). The penetration of ZnO nanoparticles was studied by scanning electron microscopy and energy dispersive X-ray spectroscopy. The tested ZnO particles did not penetrate into viable layers of the intact porcine skin. The particles tend to accumulate on the skin folds and in these regions they may penetrate into the horny layer.
Assuntos
Óxido de Zinco/química , Animais , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos da radiação , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Azul de Metileno/química , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Espectrometria por Raios X , Suínos , Raios UltravioletaRESUMO
Spray drying is a technique used to produce solid particles from liquid solutions, emulsions or suspensions. Buchi Labortechnik developed the latest generation of spray dryers, Nano Spray Dryer B-90. This study aims to obtain, directly, submicron drug particles from an organic solution, employing this equipment and using dexamethasone as a model drug. In addition, we evaluated the influence of both the type of solvent and surfactant on the properties of the powders using a 3(2) full factorial analysis. The particles were obtained with high yields (above 60%), low water content (below 2%) and high drug content (above 80%). The surface tension and the viscosity were strongly influenced by the type of solvent. The highest powder yields were obtained for the highest surface tension and the lowest viscosity of the drug solutions. The use of ionic surfactants led to higher process yields. The laser diffraction technique revealed that the particles deagglomerate into small ones with submicrometric size, (around 1 µm) that was also observed by scanning electron microscopy. Interaction between the raw materials in the spray-dried powders was verified by calorimetric analysis. Thus, it was possible to obtain dexamethasone submicrometric particles by vibrational atomization from organic solution.
Assuntos
Dexametasona/química , Solventes/química , Tensoativos/química , Tecnologia Farmacêutica/métodos , Excipientes/química , Microscopia Eletrônica de Varredura/métodos , Tamanho da Partícula , Pós/química , Soluções/química , Propriedades de Superfície , Tensão Superficial , ViscosidadeRESUMO
The aim of this study was to evaluate, for the first time, the antifungal efficacy of nanocapsules and nanoemulsions containing Melaleuca alternifolia essential oil (tea tree oil) in an onychomycosis model. The antifungal activity of nanostructured formulations was evaluated against Trichophyton rubrum in two different in vitro models of dermatophyte nail infection. First, nail powder was infected with T. rubrum in a 96-well plate and then treated with the formulations. After 7 and 14 days, cell viability was verified. The plate counts for the samples were 2.37, 1.45 and 1.0 log CFU mL(-1) (emulsion, nanoemulsion containing tea tree oil and nanocapsules containing tea tree oil, respectively). A second model employed nails fragments which were infected with the microorganism and treated with the formulations. The diameter of fungal colony was measured. The areas obtained were 2.88 ± 2.08 mm(2), 14.59 ± 2.01 mm(2), 40.98 ± 2.76 mm(2) and 38.72 ± 1.22 mm(2) for the nanocapsules containing tea tree oil, nanoemulsion containing tea tree oil, emulsion and untreated nail, respectively. Nail infection models demonstrated the ability of the formulations to reduce T. rubrum growth, with the inclusion of oil in nanocapsules being most efficient.
Assuntos
Portadores de Fármacos , Nanocápsulas , Óleo de Melaleuca/farmacologia , Trichophyton/efeitos dos fármacos , Contagem de Colônia Microbiana , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana/métodos , Viabilidade Microbiana/efeitos dos fármacos , Unhas/microbiologia , SuspensõesRESUMO
OBJECTIVE: The use of spray-dried powders containing tretinoin-loaded nanocapsules instead of the original liquid suspension, aimed at the preparation of dermatological nanomedicines with improved photostability, was investigated. METHODS: Powders were prepared using lactose as a drying adjuvant. Hydrogels were prepared using two approaches: dispersing Carbopol Ultrez 10 in an aqueous redispersion of the powder or incorporating the powder in previously formed hydrogels. RESULTS AND DISCUSSION: The photodegradation of tretinoin in hydrogels prepared with the powders showed similar half-life times (around 19.5 h) compared to preparations with the original liquid nanocapsules (20.7 ± 1.4 h), regardless of the preparation approach. In addition, the topical nanomedicines prepared with the spray-dried powders presented a significant improvement in tretinoin photostability compared to the formulation containing the non-encapsulated drug. CONCLUSION: This study verified that the addition of the spray-dried powders containing tretinoin-loaded lipid-core nanocapsules to hydrogels did not influence the photoprotection of the drug compared with the preparation procedure using the original liquid suspension.
Assuntos
Antineoplásicos/administração & dosagem , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Nanosferas/química , Pós , Tretinoína/administração & dosagem , Administração Tópica , Antineoplásicos/química , Antineoplásicos/efeitos da radiação , Dessecação , Portadores de Fármacos , Estabilidade de Medicamentos , Meia-Vida , Nanomedicina , Tamanho da Partícula , Fotólise , Polímeros , Suspensões , Tecnologia Farmacêutica/métodos , Tretinoína/química , Tretinoína/efeitos da radiação , Raios UltravioletaRESUMO
The influence of the spray-drying process on the ability of engineered lipid-core nanocapsules to protect tretinoin against UV degradation was evaluated. This approach represents a technological alternative to improve the microbiological stability, storage and transport properties of such formulations. Tretinoin-loaded lipid-core nanocapsules or tretinoin-loaded nanoemulsion were dispersed in lactose (10% w/v) and fed in the spray-drier to obtain a solid product (spray-dried powder containing tretinoin-loaded nanocapsules or nanoemulsion--SD-TTN-NCL or SD-TTN-NE, respectively). SD-TTN-NE showed a lower (p < or = 0.05) percentage of encapsulation (89 +/- 1%) compared to SD-TTN-NCL (94 +/- 2%). Redispersed SD-TTN-NCL and SD-TTN-NE showed z-average sizes of 204 +/- 2 nm and 251 +/- 9 nm, which were close to those of the original suspensions (220 +/- 3 nm and 239 +/- 14 nm, respectively). Similar percentage of photodegradation were determined for tretinoin loaded in nanocapsules (26.15 +/- 4.34%) or in the respective redispersed spray-dried powder (28.73 +/- 6.19 min) after 60 min of UVA radiation exposure (p > 0.05). Our experimental design showed for the first time that spray-dried lipid-core nanocapsules are able to protect tretinoin against UVA radiation, suggesting that the drying process did not alter the supramolecular structure of the lipid-core nanocapsules. Such powders are potential intermediate products for the development of nanomedicines containing tretinoin.
RESUMO
OBJECTIVE: Development of a hydrogel containing rutin at 0.025% (w/w) and evaluation of its in vivo efficacy in cutaneous wound healing in rats. METHODS: Hydrogels were prepared using Carbopol Ultrez® 10 NF and an aqueous dispersion of rutin in polysorbate 80. Hydrogels were characterized by means of pH measurement, rheological and spreadability analysis and rutin content determination by liquid chromatography. The in vivo healing effect was evaluated through the regression of skin lesions in rats and by analysis of oxidative stress. RESULTS AND DISCUSSION: Hydrogels showed adequate pH values (5.50-6.50) and pseudoplastic non-Newtonian behavior. After 5 days of treatment of wounds, hydrogels containing rutin presented a higher decrease in the wound area compared to the control hydrogels. Analysis of the oxidative stress showed a decrease in lipid peroxidation and protein carbonyl content as well as an increase in catalase activity after the treatment with the hydrogel containing rutin. Furthermore, this treatment increased total protein levels. CONCLUSION: This study shows for the first time the feasibility of using dermatological formulations containing rutin to improve skin wound healing.
Assuntos
Resinas Acrílicas/química , Polissorbatos/química , Rutina/administração & dosagem , Cicatrização/efeitos dos fármacos , Administração Cutânea , Animais , Química Farmacêutica/métodos , Cromatografia Líquida/métodos , Modelos Animais de Doenças , Estudos de Viabilidade , Hidrogéis , Concentração de Íons de Hidrogênio , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Carbonilação Proteica/efeitos dos fármacos , Ratos , Ratos Wistar , Reologia , Rutina/farmacologiaRESUMO
AIM: To evaluate the effect of cationic coating of polymeric nanocapsules in sunscreen formulations on the in vitro skin penetration of benzophenone-3. METHODS: Benzophenone-3-loaded nanocapsules were prepared by the interfacial deposition of poly(ε-caprolactone) and coated by using a chitosan solution. The nanoparticles were characterized and incorporated in hydrogels. The presence of nanoparticles in hydroxyethyl cellulose gels was observed by transmission electron microscopy and photon correlation spectroscopy. Penetration studies were carried out using Franz cells with porcine skin membranes. RESULTS: Benzophenone-3-loaded chitosan-coated nanocapsules presented a mean size of 202 ± 7 nm and positive zeta potential (+21 ± 1 mV), while these values for the uncoated nanocapsules were 175 ± 1 nm and -8 ± 1 mV. Penetration profiles showed that a higher amount of benzophenone-3 remained at the skin surface and a lower amount was found in the receptor compartment after the application of the formulation containing chitosan-coated nanocapsules compared to a formulation containing its free form. CONCLUSIONS: Hydrogel containing benzophenone-3 chitosan-coated nanocapsules represents an innovative formulation to overcome limitations of sunscreen daily use.
Assuntos
Benzofenonas/farmacocinética , Quitosana/química , Absorção Cutânea , Protetores Solares/farmacocinética , Administração Cutânea , Animais , Benzofenonas/administração & dosagem , Celulose/análogos & derivados , Celulose/química , Hidrogéis , Técnicas In Vitro , Microscopia Eletrônica de Transmissão , Nanocápsulas , Tamanho da Partícula , Poliésteres/química , Protetores Solares/administração & dosagem , SuínosRESUMO
The aim of the present work was to evaluate the feasibility to convert drug-loaded nanocapsule suspensions in a solid dosage form (tablets). Dexamethasone was used as a model drug due to its low aqueous solubility and fast drug release from conventional tablets. Granules containing dexamethasone-loaded nanocapsules were obtained by a wet granulation process using a dispersion of polyvinylpirrolidone/nanocapsules as a binder system. Granules were compressed in an eccentric compression machine (D-NC-T). A control formulation (tablets without nanocapsules) was also prepared (D-T). Tablets were characterized by means of mean weight, hardness, friability, diameter, thickness, disintegration time, drug content, morphological analysis by scanning electron microscopy (SEM), and in vitro drug release studies. D-NC-T showed adequate physicochemical characteristics according to the pharmacopeial requirements in terms of mean weight, hardness, friability, disintegration time and drug content. Intact nanocapsules in tablets were observed by SEM. In vitro drug release studies showed a slower release of dexamethasone from these tablets (D-NC-T) compared to the control formulation (D-T). Results showed that these tablets represent an interesting platform to the development of oral drug delivery systems containing polymeric nanocapsules.
Assuntos
Nanocápsulas/química , Comprimidos/química , Administração Oral , Química Farmacêutica/métodos , Dexametasona/administração & dosagem , Dexametasona/farmacocinética , Sistemas de Liberação de Medicamentos , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Nanocápsulas/ultraestrutura , Nanotecnologia , Polímeros/química , Povidona/químicaRESUMO
The industrial development of polymeric nanoparticle suspensions is still limited due to their low physicochemical stability. In this paper, we evaluated the wet granulation process as an alternative method to dry polymeric nanocapsules using dexamethasone as drug model. Nanocapsule suspensions were used as granulating liquid as well as a drug-loaded-nanocarrier in the wet granulation process. Granules were evaluated regarding their drug content, mean particle size, yield, moisture content, flow properties, stability on storage, recovery studies after water redispersion and morphological characteristics (SEM). Granules containing dexamethasone-loaded polymeric nanocapsules presented good drug content (approximately 94%) and were stable for 6 months at room temperature. Morphological analyses showed nanostructures on their surface and the nanoparticles were recovered after redispersing the granules in water. These results suggest that wet granulation can be an interesting alternative to dry drug-loaded nanocapsule suspensions.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Nanocápsulas/química , Polímeros/química , Análise de Variância , Dexametasona/química , Estabilidade de Medicamentos , Microscopia Eletrônica de Varredura , Nanocápsulas/ultraestrutura , Tamanho da Partícula , Suspensões/químicaRESUMO
The influence of the polymeric amorphous materials on the physicochemical and drug release properties of drug-loaded nanocapsules as well as their role on the protection of the entrapped drug against the degradation induced by UV radiation was evaluated. Nanocapsules were prepared by interfacial deposition of preformed polymer (PLA, PLGA 50:50, and PLGA 85:15) using clobetasol propionate as the drug model. In vitro drug release was evaluated by the dialysis bag method. Photochemical stability was studied under UVA radiation. After preparation, all formulations presented nanometric mean size (180-200 nm), polydispersity index below 0.20, acid pH, negative zeta potential, and encapsulation efficiency close to 100%. Clobetasol propionate-loaded PLGA nanocapsules presented a lower physicochemical stability, showing a high drug leakage during 3 months of storage. In vitro studies showed biphasic drug release from all nanocapsules (according to an anomalous transport) and no influence of the hydrophilic characteristics of the amorphous polymeric material on the release rate. The photostability of clobetasol propionate under UVA radiation was improved by its incorporation into PLA and PLGA nanocapsules showing that besides semicrystalline polymers, amorphous polymers could also efficiently protect nanoencapsulated drugs against UV radiation.
Assuntos
Clobetasol/química , Cristalização/métodos , Portadores de Fármacos/química , Nanocápsulas/química , Nanocápsulas/ultraestrutura , Nanomedicina/métodos , Poliésteres/química , Absorção , Clobetasol/administração & dosagem , Difusão , Portadores de Fármacos/efeitos da radiação , Estabilidade de Medicamentos , Luz , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Transição de Fase , Propriedades de SuperfícieRESUMO
CONTEXT: Our group previously reported the development of dexamethasone-loaded polymeric nanocapsules as an alternative for topical dermatological treatments. OBJECTIVE: Our study aimed to prepare and characterize a hydrogel containing this system to improve the effectiveness of the glucocorticoid for cutaneous disorders. METHODS: For the antiproliferative activity assay, a dexamethasone solution and D-NC were tested on Allium cepa root meristem model. D-NC were prepared by the interfacial deposition of preformed polymer. Hydrogels were prepared using Carbopol Ultrez 10 NF, as polymer, and characterized according to the following characteristics: pH, drug content, spreadability, viscosity, and in vitro drug release. RESULTS AND DISCUSSION: Nanocapsules showed mean particle size and zeta potential of 201 +/- 6 and -5.73 +/- 0.42 nm, respectively. They demonstrated a lower mitotic index (4.62%) compared to free dexamethasone (8.60%). Semisolid formulations presented acidic pH values and adequate drug content (between 5.4% and 6.1% and 100% and 105%, respectively). The presence of nanocapsules in hydrogels led to a decrease in their spreadability factor. Intact nanoparticles were demonstrated by TEM as well as by dynamic light scattering (mean particle size < 300 nm). In vitro studies showed a controlled dexamethasone release from hydrogels containing the drug associated to the nanocapsules following the Higuchi's squared root model (k = 20.21 +/- 2.96 mg/cm(2)/h(1/2)) compared to the hydrogels containing the free drug (k = 26.65 +/- 2.09 mg/cm(2)/h(1/2)). CONCLUSION: Taking all these results together, the hydrogel containing D-NC represent a promising approach to treat antiproliferative-related dermatological disorders.
Assuntos
Dexametasona/administração & dosagem , Dexametasona/química , Portadores de Fármacos/administração & dosagem , Hidrogéis/química , Hidrogéis/síntese química , Nanocápsulas/administração & dosagem , Nanocápsulas/química , Administração Cutânea , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/análise , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fenômenos Químicos , Dexametasona/análise , Dexametasona/farmacologia , Difusão , Portadores de Fármacos/análise , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Composição de Medicamentos/métodos , Concentração de Íons de Hidrogênio , Imunossupressores/administração & dosagem , Imunossupressores/análise , Imunossupressores/química , Imunossupressores/farmacologia , Meristema/citologia , Meristema/efeitos dos fármacos , Mitose/efeitos dos fármacos , Cebolas/efeitos dos fármacos , Tamanho da Partícula , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos , Solubilidade , SuspensõesRESUMO
The aim of this study was to prepare and characterize tretinoin-loaded nanocapsules as well as to evaluate the influence of this nanoencapsulation on tretinoin photostability. Tretinoin-loaded nanocapsules (0.5 mg ml(-1)) were prepared by interfacial deposition of preformed polymer (poly-epsilon-caprolactone) using two different oily phases: capric/caprylic triglycerides and sunflower seed oil. Tretinoin-loaded nanocapsules presented drug content close to the theoretical value, encapsulation efficiencies higher than 99.9%, nanometric mean size with a polydispersity index below 0.25, and pH values between 5.0 and 7.0. Regarding photodegradation studies, tretinoin methanolic solution showed a half-life time around 40 min according to a first order equation, whereas tretinoin nanocapsule suspensions showed a half-life between 85 and 100 min (twofold higher than in methanolic solution) according to a zero order equation. Tretinoin-loaded nanocapsules improved tretinoin photostability, independently on the type of oily phase used in this study, and represent a potential system to be incorporated in topical or systemic dosage forms containing tretinoin.
Assuntos
Fármacos Dermatológicos/efeitos da radiação , Nanocápsulas , Fotólise , Tretinoína/efeitos da radiação , Raios Ultravioleta , Caprilatos/química , Química Farmacêutica , Ácidos Decanoicos/química , Fármacos Dermatológicos/química , Composição de Medicamentos , Estabilidade de Medicamentos , Estudos de Viabilidade , Meia-Vida , Cinética , Tamanho da Partícula , Óleos de Plantas/química , Poliésteres/química , Solubilidade , Óleo de Girassol , Tecnologia Farmacêutica/métodos , Tretinoína/química , Triglicerídeos/químicaRESUMO
This work reports the preparation of dexamethasone in nanoparticle-coated microparticles and the study of the influence of such microencapsulation on drug absorption across Caco-2 cell monolayers. Nanoparticle-coated microparticles were prepared by spray-drying using nanocapsules (NC) or nanospheres (NS) in aqueous suspensions as coating material. Drug contents ranged from 64 to 134mgg(-1), yields between 49% and 67% and moisture content below 2.0%. SEM and AFM analysis demonstrated that the nanoparticle-coated microparticles (20-53microm) show nanostructures on their surface with a similar diameter compared to the aqueous suspensions. The type of nanocoating material had a significant influence on the drug release profile and on the drug permeation across Caco-2 cells: NC-coated microparticles led to a prolonged release and slower transport across Caco-2 cell monolayers, while the NS-coated microparticles showed a faster release and Caco-2 transport compared to uncoated microparticles. The correlation between the amount of drug permeated and the drug released (%) suggests that the drug absorption from such a delivery system is controlled mainly by the release rate rather than by epithelial permeability. Caco-2 transport studies appear to be a useful characterization tool for the development of microparticulate oral controlled release systems.
Assuntos
Dexametasona/administração & dosagem , Dexametasona/metabolismo , Nanopartículas , Transporte Biológico , Células CACO-2 , Química Farmacêutica , Dexametasona/farmacocinética , Composição de Medicamentos , Excipientes , Humanos , Umidade , Concentração de Íons de Hidrogênio , L-Lactato Desidrogenase/metabolismo , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Modelos Estatísticos , Tamanho da Partícula , Difração de Raios XRESUMO
Ilex paraguariensis is used in Brazil as a stimulating beverage called "mate". Leaves and immature fruit extracts of Ilex paraguariensis were evaluated for their radical scavenging capacity, total methylxanthine and polyphenol contents. Antimicrobial activity of two enriched saponin fractions obtained from the fruits were also evaluated. The radical scavenging activity of the fractioned extracts was determined spectrophotometrically using 1,1-diphenylpicrylhydrazyl free radical (DPPH). The IC50o of L-ascorbic acid, ethyl acetate and n-butanol fractions from the leaves and ethyl acetate fraction from the fruits were 6.48 microg/mL, 13.26 microg/mL, 27.22 microg/mL, and 285.78 microg/mL, respectively. Total methylxanthine content was 1.16 +/- 0.06 mg/g dry weight in the fruits and 8.78 +/- 0.01 mg/g in the leaves. Total polyphenol content varied from 86.82 +/- 3 x 10(-4) to 199.91 +/- 3 x 10(-3) mg/g in leaf fractions and from 54.25 +/- 1 x 10(-3) to 110.36 +/- 4 x 10(-4) mg/g in fruit fractions. Enriched saponin fractions from the fruits showed no antimicrobial activity. To our knowledge, this are the first data available on the antioxidant/antimicrobial activities and polyphenol/methylxanthine contents of Ilex paraguariensis fruits.
Assuntos
Antioxidantes/química , Flavonoides/química , Frutas/química , Ilex paraguariensis/química , Fenóis/química , Xantinas/química , Antibacterianos/química , Antibacterianos/farmacologia , Compostos de Bifenilo , Brasil , Flavonoides/farmacologia , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Testes de Sensibilidade Microbiana , Fenóis/farmacologia , Picratos/química , Folhas de Planta/química , Polifenóis , Saponinas/química , Saponinas/farmacologia , Xantinas/farmacologiaRESUMO
Doxazosin has been evaluated for the treatment of several types of cancer. Here, the antitumor effect of the nanoencapsulated form of doxazosin was evaluated in an in vitro model of breast cancer (MCF7 cell line). Doxazosin-loaded polymeric nanocapsules (DXZ-NC) were produced by interfacial deposition of preformed polymer with homogeneous aspect, spherical shape, mean diameter of about 130nm, positive zeta potential (+5mV), and encapsulation efficiency close to 35%. The Alamar Blue® assay and cell counting were carried out to assess cell viability and cell number, respectively. Mechanism of death was evaluated by Annexin/Propidium Iodide staining, while the long-term response was assessed using the clonogenic assay. Nuclear morphometric analysis was investigated using the NMA technique. A significant decrease in cell viability and clonogenicity was observed after the treatment with DXZ-NC when compared to the non-encapsulated drug. All treatments induced apoptosis as the main mechanism of toxicity. In conclusion, the nanoencapsulation of doxazosin improved its in vitro effects in MCF7 cells, without changing the mechanism of cell death underlying its toxicity. This approach was fundamental to reduce the long-term in vitro ability of the remaining tumor cells to form new colonies after the treatment, potentially reducing the risk of tumor recurrence.
Assuntos
Neoplasias da Mama/patologia , Doxazossina/farmacologia , Nanocápsulas/química , Contagem de Células , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Clonais , Liberação Controlada de Fármacos , Feminino , Humanos , Células MCF-7 , Nanocápsulas/ultraestrutura , Tamanho da PartículaRESUMO
The generation of multi-functional drug delivery systems, namely solid dosage forms loaded with nano-sized carriers, remains little explored and is still a challenge for formulators. For the first time, the coupling of two important technologies, 3D printing and nanotechnology, to produce innovative solid dosage forms containing drug-loaded nanocapsules was evaluated here. Drug delivery devices were prepared by fused deposition modelling (FDM) from poly(ε-caprolactone) (PCL) and Eudragit® RL100 (ERL) filaments with or without a channelling agent (mannitol). They were soaked in deflazacort-loaded nanocapsules (particle size: 138nm) to produce 3D printed tablets (printlets) loaded with them, as observed by SEM. Drug loading was improved by the presence of the channelling agent and a linear correlation was obtained between the soaking time and the drug loading (r2=0.9739). Moreover, drug release profiles were dependent on the polymeric material of tablets and the presence of the channelling agent. In particular, tablets prepared with a partially hollow core (50% infill) had a higher drug loading (0.27% w/w) and faster drug release rate. This study represents an original approach to convert nanocapsules suspensions into solid dosage forms as well as an efficient 3D printing method to produce novel drug delivery systems, as personalised nanomedicines.
Assuntos
Sistemas de Liberação de Medicamentos , Nanocápsulas/química , Impressão Tridimensional , Comprimidos , Resinas Acrílicas/química , Poliésteres/química , Polímeros , Tecnologia FarmacêuticaRESUMO
The treatment of various hair disorders has become a central focus of good dermatologic patient care as it affects men and women all over the world. For many inflammatory-based scalp diseases, glucocorticoids are an essential part of treatment, even though they are known to cause systemic as well as local adverse effects when applied topically. Therefore, efficient targeting and avoidance of these side effects are of utmost importance. Optimizing the balance between drug release, interfollicular permeation, and follicular uptake may allow minimizing these adverse events and simultaneously improve drug delivery, given that one succeeds in targeting a sustained release formulation to the hair follicle. To test this hypothesis, three types of polymeric nanocarriers (nanospheres, nanocapsules, lipid-core nanocapsules) for the potent glucocorticoid clobetasol propionate (CP) were prepared. They all exhibited a sustained release of drug, as was desired. The particles were formulated as a dispersion and hydrogel and (partially) labeled with Rhodamin B for quantification purposes. Follicular uptake was investigated using the Differential Stripping method and was found highest for nanocapsules in dispersion after application of massage. Moreover, the active ingredient (CP) as well as the nanocarrier (Rhodamin B labeled polymer) recovered in the hair follicle were measured simultaneously, revealing an equivalent uptake of both. In contrast, only negligible amounts of CP could be detected in the hair follicle when applied as free drug in solution or hydrogel, regardless of any massage. Skin permeation experiments using heat-separated human epidermis mounted in Franz Diffusion cells revealed equivalent reduced transdermal permeability for all nanocarriers in comparison to application of the free drug. Combining these results, nanocapsules formulated as an aqueous dispersion and applied by massage appeare to be a good candidate to maximize follicular targeting and minimize drug penetration into the interfollicular epidermis. We conclude that such nanotechnology-based formulations provide a viable strategy for more efficient drug delivery to the hair follicle. Moreover, they present a way to minimize adverse effects of potent glucocorticoids by releasing the drug in a controlled manner and simultaneously decreasing interfollicular permeation, offering an advantage over conventional formulations for inflammatory-based skin/scalp diseases.