RESUMEN
New adjuvant strategies are needed to improve protein-based subunit vaccine immunogenicity. We examined the potential to use nanostructure of 6-O-ascorbyl palmitate to formulate ovalbumin (OVA) protein and an oligodeoxynucleotide (CpG-ODN) (OCC). In mice immunized with a single dose, OCC elicited an OVA-specific immune response superior to OVA/CpG-ODN solution (OC). Rheological studies demonstrated OCC's self-assembling viscoelastic properties. Biodistribution studies indicated that OCC prolonged OVA and CpG-ODN retention at injection site and lymph nodes, reducing systemic spread. Flow-cytometry assays demonstrated that OCC promoted OVA and CpG-ODN co-uptake by Ly6ChiCD11bhiCD11c+ monocytes. OCC and OC induced early IFN-γ in lymph nodes, but OCC led to higher concentration. Conversely, mice immunized with OC showed higher serum IFN-γ concentration compared to those immunized with OCC. In mice immunized with OCC, NK1.1+ cells were the IFN-γ major producers, and IFN-γ was essential for OVA-specific IgG2c switching. These findings illustrate how this nanostructure improves vaccine's response.
Asunto(s)
Nanoestructuras , Oligodesoxirribonucleótidos , Ovalbúmina , Vacunas de Subunidad , Animales , Nanoestructuras/química , Vacunas de Subunidad/inmunología , Vacunas de Subunidad/química , Vacunas de Subunidad/farmacocinética , Ratones , Oligodesoxirribonucleótidos/química , Oligodesoxirribonucleótidos/farmacocinética , Ovalbúmina/inmunología , Ovalbúmina/química , Femenino , Ratones Endogámicos C57BL , Adyuvantes Inmunológicos/química , Adyuvantes Inmunológicos/farmacocinética , Interferón gamma/metabolismo , Distribución Tisular , Ácido Ascórbico/análogos & derivadosRESUMEN
Neglected tropical diseases are a major health problem throughout the world, and there are few effective and safe drugs. In this study, we report the design and synthesis of a novel series of carbonates of eugenol using different aliphatic alcohols and N,N-carbonyldiimidazole. Spectroscopic techniques, including 1 H nuclear magnetic resonance (NMR), 13 C NMR, Fourier transform infrared, and high-resolution mass spectrometry, were used to confirm the structures of the synthesized compounds. In vitro and in silico studies of prodrugs of eugenol were performed to determine their antiplasmodial, trypanocidal, and leishmanicidal activities, and also their cytotoxicity. Compounds were highly active against Leishmania braziliensis and Plasmodium falciparum, whereas the activity shown for Trypanosoma cruzi was moderate. Molecular docking was used to determine a possible mode of action of eugenol against the dihydroorotate dehydrogenase of the three parasites (TcDHODH, LbDHODH, and PfDHODH). Notably, the docking results showed that eugenol not only has binding energy similar to that of the natural substrate (-7.2 and -7.1, respectively) but also has interactions with relevant biological residues of PfDHODH. This result indicates that eugenol could act as a substrate for PfDHODH in the pyrimidine biosynthesis pathway of P. falciparum. In conclusion, the combination of certain aliphatic alcohols and eugenol through a carbonate bond could significantly increase the antiparasitic activity of this class of compounds, which merits further studies.
Asunto(s)
Leishmania braziliensis , Trypanosoma cruzi , Carbonatos/farmacología , Eugenol/farmacología , Simulación del Acoplamiento Molecular , Plasmodium falciparum , Relación Estructura-ActividadRESUMEN
We are reporting for the first time the synthesis and application of an innovative nanometric system for the controlled topic release of melatonin in the retina. The ethylcellulose nanocapsules were characterized by diverse physicochemical techniques (scanning electron microscopy, zeta potential, hydrodynamic diameters) and an in vitro release study was done. A complete ex vivo and in vivo trans-corneal permeation and an irritation study were carried out with the new formulations in albino rabbits, to which a retinal degenerative model was induced. The results obtained demonstrate that the in vitro release of melatonin (1 mg/mL and 2 mg/mL) transported by nanocapsules is slower when compared to a solution of melatonin. Greater penetration of melatonin through the cornea was demonstrated by ex vivo and in vivo tests. This can be attributable to an enhanced neuroprotective effect of melatonin on retinal ganglion cells when it is included in ethylcellulose nanocapsules compared to a solution of melatonin. These outstanding findings add promising new perspectives to current knowledge about administrations using nano-technological tools in the treatment of neurodegenerative diseases at the ocular level.
Asunto(s)
Celulosa/análogos & derivados , Melatonina/administración & dosificación , Degeneración Retiniana/tratamiento farmacológico , Células Ganglionares de la Retina/patología , Animales , Antioxidantes/administración & dosificación , Celulosa/farmacología , Modelos Animales de Enfermedad , Composición de Medicamentos , Microscopía Electrónica de Rastreo , Nanopartículas/ultraestructura , Conejos , Degeneración Retiniana/diagnóstico , Células Ganglionares de la Retina/efectos de los fármacosRESUMEN
Cystic echinococcosis (CE), which is caused during the metacestode larval stage of Echinococcus granulosus, is a life-threatening disease and is very difficult to treat. At present, the FDA-approved antihelmintic drugs are mebendazole (MBZ), albendazole (ABZ) and its principal metabolite ABZ sulfoxide (ABZSO), but as these have a therapeutic efficacy over 50%, underlining the need for new drug delivery systems. The aim of this work was the optimization and characterization of previously developed ABZ lipid nanocapsules (ABZ-LNCs) and evaluate their efficacy in mice infected with E. granulosus. LNCs were prepared by the phase inversion technique and characterized in terms of size, surface charge, drug loading, and in vitro stability followed by an in vivo proof-of-concept using a murine model infected with E. granulosus. Stable particle dispersions with a narrow size distribution and high efficiency of encapsulation (≥90%) were obtained. ABZ-LNCs showed a greater chemoprophylactic efficacy than ABZ suspension administered by the oral route as 4 out of the 10 ABZ-LNCs treated mice did not develop any cysts, whereas the infection progressed in all mice from the ABZ suspension group. Regarding the ultrastructural studies of cysts, mice treated with ABZ-LNCs or ABZ suspension revealed changes in the germinal layer. However, the extent of the damage appeared to be greater after ABZ-LNC administration compared to the suspension treatment. These results suggest that ABZ-LNCs could be a promising novel candidate for ABZ delivery to treat CE.
Asunto(s)
Albendazol/uso terapéutico , Anticestodos/uso terapéutico , Equinococosis/tratamiento farmacológico , Echinococcus granulosus/efectos de los fármacos , Albendazol/administración & dosificación , Albendazol/química , Animales , Anticestodos/administración & dosificación , Anticestodos/química , Bovinos , Cromatografía Líquida de Alta Presión , Equinococosis/prevención & control , Echinococcus granulosus/ultraestructura , Femenino , Intestinos/química , Ratones , Microscopía Electrónica de Rastreo , Nanocápsulas/normas , Nanocápsulas/ultraestructura , Enfermedades Desatendidas/tratamiento farmacológico , Enfermedades Desatendidas/prevención & control , Tamaño de la Partícula , Polvos , Estómago/químicaRESUMEN
This work focuses on improving the effectiveness of current therapies against glaucoma by incorporating self-assembled polymers into the ophthalmic formulation. To that end, we first studied the influence of the dispersing medium on the mechanical performance of self-assembling elastin-like (EL) and silk-elastin-like (SEL) hydrogels by conducting rheological tests. These polymers were subsequently incorporated into the antiglaucoma formulation, which contains timolol maleate (TM) as active ingredient, and in vivo tests, namely adhesion tests and intraocular pressure measurements (IOP), were performed in New Zealand rabbits. An enhanced reduction in IOP due to the presence of the polymers was observed. Moreover, differences in the effectiveness between both EL- and SEL-hydrogels, which can be explained on the basis of the different rheological properties displayed by these two systems, were also encountered. The results point to the potential of this system as a basis for the development of an ophthalmic formulation against glaucoma.
Asunto(s)
Antihipertensivos/uso terapéutico , Portadores de Fármacos/química , Glaucoma/tratamiento farmacológico , Presión Intraocular/efectos de los fármacos , Timolol/uso terapéutico , Animales , Rastreo Diferencial de Calorimetría , Línea Celular , Liberación de Fármacos , Elastina/química , Ojo/efectos de los fármacos , Fibroblastos , Humanos , Hidrogeles/química , Masculino , Modelos Animales , Soluciones Oftálmicas/uso terapéutico , Conejos , Reología , Seda/química , Resultado del TratamientoRESUMEN
A study was performed for the development and validation of a method of High Performance Liquid Chromatography (HPLC) for the identification and simultaneous quantification of Gallein and Human Serum Albumin (HSA). In addition, this work presents the development and physicochemical characterization of this new pharmaceutical formulation of HSA nanoparticles loaded with Gallein for potential use in the treatment of Alzheimer's disease. The method was developed with the purpose of determining the performance of the synthesis process of nanoparticles and the efficiency of encapsulation of the drug in the nanosystem. The HPLC mobile phase consisted of ACN:H2O:TEA:H3PO4 (50:49.8:0.1:0.1 v/v/v) pumped at a flow rate of 0.8 mL/min, isocratic mode, and the measurement were carried out at 220 nm. Chromatographic runs were performed on a C18 column (150 × 4.60 mm; 5 µm size particles). The HPLC-method was validated following the International Conference on Harmonisation (ICH) of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines and was used to simultaneously quantify the two components of the nanoformulation. Thus, the values obtained through the validated method were 43 % for drug encapsulation efficiency (% EE) and the synthesis performance (% yield) was 96 %. Moreover, the nanoformulation was characterized by DLS, the results showed that the average particle size was 217 nm, with a PDI of (0.085 ± 0.005) and a potential Z of -29.7 mV. Therefore, the developed method has proven useful in providing accurate simultaneous measurements of HSA and Gallein from albumin nanoparticles. It is advantageous since it is able to reduce the time and facilitate the determination of Gallein encapsulation efficiency and yield of albumin nanoparticles.
Asunto(s)
Nanopartículas , Cromatografía Líquida de Alta Presión/métodos , Reproducibilidad de los Resultados , Humanos , Nanopartículas/química , Modelos Lineales , Cromatografía de Fase Inversa/métodos , Albúmina Sérica Humana/química , Albúmina Sérica Humana/análisis , Límite de DetecciónRESUMEN
Solid dispersions (SDs) containing the anthelmintic compound albendazole (ABZ) and either Pluronic 188 (P 188) or polyethylene glycol 6000 (PEG 6000) as hydrophilic carriers were formulated. Drug-polymers interactions in solid state were investigated using different techniques. Only a 4% of total ABZ was dissolved at 5 min post-incubation, reaching dissolution rates of 32.8% (PEG 6000) and 69.4% (P 188) in SDs. In this way, P 188 was substantially more efficient as ABZ dissolution promoter in comparison to PEG 6000, especially at the initial stages of the dissolution processes (<30 min). An increased systemic availability (p < 0.001) was obtained when ABZ was administered as ABZ-P 188 SDs, with a 50% enhancement in systemic exposure (AUC values) compared to treatment with an ABZ suspension. Consistently, the Cmax increased 130% (p < 0.001) following treatment with P 188 based SD ABZ formulation. For the ABZ-PEG 6000 SD formulation, the favorable effect on ABZ systemic availability did not reached statistical significance compared to the control group. The study reported here showed the utility of pharmacokinetic assays performed on mice as a model for preliminary drug formulation screening studies.
Asunto(s)
Albendazol/química , Albendazol/farmacocinética , Portadores de Fármacos/química , Albendazol/administración & dosificación , Animales , Área Bajo la Curva , Disponibilidad Biológica , Química Farmacéutica/métodos , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/farmacocinética , Evaluación Preclínica de Medicamentos/métodos , Masculino , Ratones , Ratones Endogámicos BALB C , Polietilenglicoles/química , Solubilidad , Suspensiones/administración & dosificación , Suspensiones/química , Suspensiones/farmacocinéticaRESUMEN
Solids dispersions (SDs) have been proposed as an alternative to improve the dissolution rate of low solubility drugs. SDs containing albendazole (ABZ; 5, 10, 25, and 50% w/w) and Pluronic 188 (P 188) as hydrophilic carrier were formulated. The obtained SDs were assessed in comparison to physical mixtures (PMs). Drug-polymer interactions in solid state were investigated using Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction analysis. No chemical interaction was found between ABZ and poloxamer. The dissolution profiles indicated that ABZ incorporated in SDs and PMs was rapidly released, reaching rapidly the steady state. Increased dissolution rates are usually observed at the highest polymer proportions. However, an opposite effect for SDs as well as for PMs was observed in the assays described here. The systems with the lowest P 188 percentages (SD4, SD3; PM4, PM3) tended to be more effective in increasing the ABZ dissolution rate. Such a result can be attributed to the fact that concentrated aqueous solutions of Poloxamer may form thermo-reversible gels. The physical-mechanical properties indicated that SDs possess improved flow and compacting properties compared to PMs. Thus, ABZ SDs would be more convenient for solid dosage form design and manufacture.
Asunto(s)
Albendazol/química , Antihelmínticos/química , Poloxámero/química , Albendazol/farmacocinética , Antihelmínticos/farmacocinética , Composición de Medicamentos , Sistemas de Liberación de Medicamentos , Excipientes , Pruebas de Dureza , Polietilenglicoles/química , Povidona , SolubilidadRESUMEN
Helminthic infections are produced by different types of worms and affect millions of people worldwide. Benzimidazole compounds such as ricobendazole (RBZ) are widely used to treat helminthiasis. However, their low aqueous solubility leads to poor gastrointestinal dissolution, absorption and potential lack of efficacy. The formulation of nanocrystals (NCs) have become the strategy of preference for hydrophobic drugs. In this work, we prepared RBZ NCs (RBZ-NCs) by an optimized combination of bead milling and spray-drying. Following the physicochemical characterization, a comparative pharmacokinetic evaluation of RBZ-NCs was performed in dogs using as controls a micronized powdered form of RBZ (mRBZ) and a physical mixture of drug and stabilizer 1:1 (PM). The particle size of the redispersed RBZ-NCs was 181.30 ± 5.93 nm, whereas DSC, PXRD and FTIR analyses demonstrated that the active ingredient RBZ remained physicochemically unchanged after the manufacture process. RBZ-NCs exhibited improved in vitro biopharmaceutical behaviour when compared to mRBZ. Consequently, the pharmacokinetic trial demonstrated a significant increase in the drug oral absorption, with an AUC0-∞ 1.9-fold higher in comparison to that obtained in animals treated with mRBZ. This novel formulation holds substantial potential for the development of new/alternative treatments for helminth infections both in human and veterinary medicine.
Asunto(s)
Albendazol/análogos & derivados , Nanopartículas/química , Tamaño de la Partícula , Secado por Pulverización , Albendazol/síntesis química , Albendazol/farmacocinética , Animales , Antihelmínticos/síntesis química , Antihelmínticos/farmacocinética , Estudios Cruzados , Perros , Femenino , MasculinoRESUMEN
The interaction between a cationic polymethacrylate (Eudragit E, EU) and a set of 7 drugs having acid groups (AH) was studied. Two series of complexes were prepared (EU-AH50 and EU-AH50Cl50), in both 50% of the basic groups of EU were neutralized with AH but in the second, the remaining groups were further neutralized with HCl. These products were stable solid ionic complexes that were characterized through infrared spectroscopy and X-ray power diffraction. All EU-AH50Cl50 at 5-10mg/ml produced clear optically isotropic aqueous dispersions. This result was in line with the increase of the apparent solubility of the low solubility AH assayed. The species distribution, as determined on the complex of diclofenac, showed a degree of counterion condensation as high as 97.9%. The reversibility of the counterion condensation, as well as the affinity between EU and AH, was evaluated through the proton withdrawing effect produced by the ionic exchange generated by titration with NaCl. Besides, drug delivery in bicompartimental Franz cells towards water as receptor medium was very slow. However, it was increased as water was replaced by NaCl solution that upon diffusion generates ionic exchange. Therefore, the EU-AH system behaves as a reservoir of drug able to deliver it in simulated biological fluid.
Asunto(s)
Acrilatos/química , Aniones/química , Cationes/química , Preparaciones Farmacéuticas/química , Polímeros/química , Algoritmos , Aminas/química , Preparaciones de Acción Retardada/química , Difusión , Estabilidad de Medicamentos , Concentración de Iones de Hidrógeno , Iones/química , Sacarina/química , Cloruro de Sodio/química , Solubilidad , Espectrofotometría Ultravioleta/instrumentación , Espectrofotometría Ultravioleta/métodos , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Electricidad Estática , Difracción de Rayos X/métodosRESUMEN
The aim of this work was the development of extended release tablets of 500 mg of ciprofloxacin based on swellable drug polyelectrolyte matrices (SDPM). A set of complexes of carbomer, ciprofloxacin and sodium, (CB-Cip)(50)Na( x ), having a molar ratio Cip/CB acid groups of 0.5 and variable proportions of Na(+) was used to prepare SDPM. Characterization of complexes by FT-IR, powder X-ray diffraction and thermal analysis revealed that Cip, in its protonated form, is ionically bonded to the functional groups of CB. Rates of fluid uptake of (CB-Cip)(50)Na( x ) matrices as well as Cip release in simulated gastric fluid were modulated by changes in the proportion of Na(+) incorporated in the complexes. A direct correlation between fluid uptake and delivery rate was observed along the series of matrices. Release rates were modulated from 1.4 mg/min to 25 mg/min in going from (CB-Cip)(50)Na(10) to (CB-Cip)(50)Na(14). The analysis of kinetic data suggest that rates of swelling, ionic pair dissociation and drug diffusion play a role in the kinetic control of delivery. Complexes were satisfactorily prepared and processed together with small amounts of antiadherent and lubricant excipients to obtain a series of extended release SDPM tablets through the current tableting technology processes. Cip release from matrices was widely modulated by the composition of the complexes yielding a flexible system that allows selecting a composition that releases in 120 min 90% of the dose in simulated gastric fluid.
Asunto(s)
Resinas Acrílicas/química , Resinas Acrílicas/farmacocinética , Ciprofloxacina/química , Ciprofloxacina/farmacocinética , Electrólitos/química , Electrólitos/farmacocinética , Química Farmacéutica , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Jugo Gástrico/química , Jugo Gástrico/metabolismo , Polímeros/química , Polímeros/farmacocinética , Espectroscopía Infrarroja por Transformada de Fourier , ComprimidosRESUMEN
There is a need for new vaccine adjuvant strategies that offer both vigorous antibody and T-cell mediated protection to combat difficult intracellular pathogens and cancer. To this aim, we formulated class-B synthetic oligodeoxynucleotide containing unmethylated cytosine-guanine motifs (CpG-ODN) with a nanostructure (Coa-ASC16 or coagel) formed by self-assembly of 6-0-ascorbyl palmitate ester. Our previous results demonstrated that mice immunized with ovalbumin (OVA) and CpG-ODN formulated with Coa-ASC16 (OVA/CpG-ODN/Coa-ASC16) elicited strong antibodies (IgG1 and IgG2a) and Th1/Th17 cellular responses without toxic systemic effects. These responses were superior to those induced by a solution of OVA with CpG-ODN or OVA/CpG-ODN formulated with aluminum salts. In this study, we investigated the capacity of this adjuvant strategy (CpG-ODN/Coa-ASC16) to elicit CD8+ T-cell response and some of the underlying cellular and molecular mechanisms involved in adaptive response. We also analyzed whether this adjuvant strategy allows a switch from an immunization scheme of three-doses to one of single-dose. Our results demonstrated that vaccination with OVA/CpG-ODN/Coa-ASC16 elicited an antigen-specific long-lasting humoral response and importantly-high quality CD8+ T-cell immunity with a single-dose immunization. Moreover, Coa-ASC16 promoted co-uptake of OVA and CpG-ODN by dendritic cells. The CD8+ T-cell response induced by OVA/CpG-ODN/Coa-ASC16 was dependent of type I interferons and independent of CD4+ T-cells, and showed polyfunctionality and efficiency against an intracellular pathogen. Furthermore, the cellular and humoral responses elicited by the nanostructured formulation were IL-6-independent. This system provides a simple and inexpensive adjuvant strategy with great potential for future rationally designed vaccines.
Asunto(s)
Antígenos/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Interferón Tipo I/metabolismo , Oligodesoxirribonucleótidos/inmunología , Adyuvantes Inmunológicos , Animales , Antígenos/química , Citocinas/metabolismo , Humanos , Inmunidad Humoral , Ratones , Ratones Noqueados , Nanoestructuras , Oligodesoxirribonucleótidos/química , Ovalbúmina/inmunología , Transducción de Señal , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismoRESUMEN
An isocratic high-performance liquid chromatographic method was developed, optimized and validated for the determination of nystatin in human saliva (UV and fluorescence detection). A reversed-phase Luna C18 column (25 degrees C), with a mobile phase of MeOH, H2O, and DMF (70:20:10, v/v/v), and a flow-rate of 0.8 ml/min were used. The elution time for nystatin was 5.8+/-0.2 min. Calibration curves in human saliva were linear from 0.78 to 50 microg/ml. Limits of quantification were 0.78 microg/ml and 0.75 microg/ml for UV and fluorescence detection, respectively. The accuracy and precision values of intra- and inter-day variation studies were within acceptable limits, according to FDA guidelines. The described method has proved to be useful to give accurate measurements of nystatin in real samples.
Asunto(s)
Antifúngicos/análisis , Cromatografía Líquida de Alta Presión/métodos , Nistatina/análisis , Saliva/química , Antifúngicos/administración & dosificación , Preparaciones de Acción Retardada , Estabilidad de Medicamentos , Humanos , Estructura Molecular , Nistatina/administración & dosificación , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Release kinetics of the volatile compounds of oregano EO microcapsules and the relation with the antioxidant activity were studied. Different wall material (WM) to core (C) ratios (1:1 and 2:1; WM:C), addition of colloidal silicon dioxide (CSD); and different storage conditions: 23 °C (room temperature; R) and 4 °C (fridge temperature; F) were evaluated for 90 d. Volatile compounds, total phenolic content (TPC), free radical scavenging activity (FRSA), and Trolox equivalent antioxidant capacity (TEAC) were measured. The formulas 2:1 (WM:C) (R and F) without CSD behaved differently from the rest, exhibited a higher antioxidant activity, and released less amount of volatile compounds after 90 d. These treatments grouped together in the cluster analysis, showing the highest TPC (81.54 mg gallic ac/g), FRSA (8.66%), and TEAC (12.35 µg Trolox/g). The addition of CSD facilitated the released of volatile compounds through storage time and promoted losses in the antioxidant activity. The temperature had a significant effect in most of the evaluated variables. However, this effect was more noticeable in F2 (1:1, CSD). PRACTICAL APPLICATION: Oregano essential oil has antioxidant, antimicrobial, and sensory preserving properties. However, it is susceptible to volatilization and is degraded by external factors. Its addition into food matrices is restricted due to low solubility and hydrophobicity. The antioxidant activity of oregano EO is preserved after the process of microencapsulation by spray-drying that extends its stability during storage. Oregano EO microcapsules are an alternative of delivery which protects and extends the shelf life of this essential oil, overcomes stability related limitations and preserves its desirable characteristics allowing these kind of microcapsules to be later incorporated into food products. These microcapsules could be used as a natural additive/flavouring with antioxidant properties.
Asunto(s)
Antioxidantes/química , Aceites Volátiles/química , Origanum/química , Extractos Vegetales/química , Cápsulas/química , Humanos , Fenoles/química , GustoRESUMEN
This study deals with the development and characterization of the delivery properties of swellable drug-polyelectrolyte matrices (SDPM) of alginic acid (AA). Complexes (AA-D)(x) in solid state were obtained by neutralization of AA with different molar proportions (x) of model basic drugs (D), in which D is atenolol, metoclopramide and propranolol. They were characterized by DSC, IR and X-ray diffraction. Matrices prepared by compaction of (AA-D)(x) alone or in a mixture with sodium alginate (NaAA) were subjected to measurements of solvent up-take, release kinetics and erosion in three media (water, buffer of pH 6.8 and 0.01 M HCl). In addition, the dynamics of swelling was also evaluated. All SDPM assayed exhibited a remarkable zero order of delivery in water and buffer of pH 6.8 and also in two-step delivery experiments: 2 h in acid medium followed by a second step at pH 6.8. Experimental results indicate that the erosion of the hydrogel layer is the main delivery process. Delivery rate, can be modulated either by varying the composition of (AA-D)(x) or by diluting it with NaAA.
Asunto(s)
Alginatos/química , Hidrogeles/química , Agua/química , Atenolol/química , Rastreo Diferencial de Calorimetría , Sistemas de Liberación de Medicamentos , Ácido Glucurónico/química , Dureza , Ácidos Hexurónicos/química , Metoclopramida/química , Propranolol/química , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos XRESUMEN
Glaucoma is characterized by increased intraocular pressure (IOP) that results in blindness if it remains untreated. Acetazolamide (AZM) is a carbonic anhydrase inhibitor, mainly used to reduce IOP in the treatment of glaucoma. However, the potential of topical treatment is limited, due to its low permeability across the ocular epithelium. An alternative to overcome this limitation is the incorporation of AZM in nanoparticulate systems, such as polymeric nanocapsules (NCs). In this way, the aim of this work was to prepare and characterize NC formulations containing AZM, using ethylcellulose (EC) and Eudragit(®) RS100 (EUD) as encapsulating polymers. The formulations showed high encapsulation efficiency. Particle size measurements showed that NCs are in the nanometric range. Comparing both groups of formulations, the NCEC proved to be smaller than those prepared with EUD. The formulations prepared with EC showed negative zeta potentials, while NCs of EUD were positively charged. For both groups of formulations, no more than 30% of drug was released in 120 min. Ex vivo and in vivo studies evidenced that the NCEC formulations were the most efficient, because an increased amount of permeated drug was observed, along with a greater IOP decrease and longer duration of the effect in normotensive rabbits.
Asunto(s)
Acetazolamida/administración & dosificación , Administración Oftálmica , Córnea/efectos de los fármacos , Presión Intraocular/efectos de los fármacos , Nanopartículas/administración & dosificación , Polímeros/administración & dosificación , Acetazolamida/metabolismo , Administración Tópica , Animales , Córnea/metabolismo , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/metabolismo , Presión Intraocular/fisiología , Masculino , Nanopartículas/metabolismo , Técnicas de Cultivo de Órganos , Tamaño de la Partícula , Polímeros/metabolismo , ConejosRESUMEN
Modern subunit vaccines require the development of new adjuvant strategies. Recently, we showed that CpG-ODN formulated with a liquid crystal nanostructure formed by self-assembly of 6-O-ascorbyl palmitate (Coa-ASC16) is an attractive system for promoting an antigen-specific immune response to weak antigens. Here, we showed that after subcutaneous injection of mice with near-infrared fluorescent dye-labeled OVA antigen formulated with Coa-ASC16, the dye-OVA was retained at the injection site for a longer period than when soluble dye-OVA was administered. Coa-ASC16 alone elicited a local inflammation, but how this material triggers this response has not been described yet. Although it is known that some materials used as a platform are not immunologically inert, very few studies have directly focused on this topic. In this study, we explored the underlying mechanisms concerning the interaction between Coa-ASC16 and the immune system and we found that the whole inflammatory response elicited by Coa-ASC16 (leukocyte recruitment and IL-1ß, IL-6 and IL-12 production) was dependent on the MyD88 protein. TLR2, TLR4, TLR7 and NLRP3-inflammasome signaling were not required for induction of this inflammatory response. Coa-ASC16 induced local release of self-DNA, and in TLR9-deficient mice IL-6 production was absent. In addition, Coa-ASC16 revealed an intrinsic adjuvant activity which was affected by MyD88 and IL-6 absence. Taken together these results indicate that Coa-ASC16 used as a vaccine platform is effective due to the combination of the controlled release of antigen and its intrinsic pro-inflammatory activity. Understanding how Coa-ASC16 works might have significant implications for rational vaccine design.
Asunto(s)
Adyuvantes Inmunológicos/química , Antígenos/administración & dosificación , Ácido Ascórbico/análogos & derivados , Factor 88 de Diferenciación Mieloide/metabolismo , Vacunas/administración & dosificación , Animales , Ácido Ascórbico/química , Preparaciones de Acción Retardada , Humanos , Inflamasomas/efectos de los fármacos , Inflamación/inducido químicamente , Inflamación/patología , Interleucinas/biosíntesis , Leucocitos/efectos de los fármacos , Cristales Líquidos , Ratones , Ratones Noqueados , Factor 88 de Diferenciación Mieloide/genética , Ovalbúmina/inmunología , Receptor Toll-Like 9/biosíntesis , Receptor Toll-Like 9/genética , Receptores Toll-Like/biosíntesisRESUMEN
In vitro mucoadhesion, water uptake, and drug release of nystatin (N) from matrices of carbomer (C) and lyophilized carbomer sodium salt (CNaL) mixtures were evaluated. Matrices with different ratios C:CNaL were prepared by direct compression. Commercial C as well as lyophilized powder (CL) were used. In vitro mucoadhesion increased as the proportion of C in the matrix was raised. The same effect was observed when C was replaced by CL. Matrices in which C was replaced by CL showed an increase of both water uptake and release rates. Besides, the release of N from matrices CL:CNaL exhibited a kinetics with Super Case II (n>1) mechanism. However, for C:CNaL matrices, drug release was slower and exhibited a biphasic profile with a first stage characterized by either an anomalous (n<1, for C>or=50%) or a Case II (n approximately 1.0, C<50%) mechanisms. After that period, the mechanism changed to Super Case II transport (n>1).
Asunto(s)
Resinas Acrílicas/química , Antifúngicos/administración & dosificación , Sistemas de Liberación de Medicamentos , Nistatina/administración & dosificación , Antifúngicos/química , Antifúngicos/farmacocinética , Nistatina/química , Nistatina/farmacocinética , Comprimidos , Agua/químicaRESUMEN
The adjuvants approved in human vaccine with recombinant/purified antigens induce weak cellular immune response and so the development of new adjuvant strategies is critical. CpG-ODN has successfully been used as an adjuvant (phase I-III clinical trials) but its bioavailability needs to be improved. We investigated the adjuvant ability of CpG-ODN formulated with a liquid crystal nanostructure of 6-O-ascorbyl palmitate (Coa-ASC16). Mice immunized with OVA/CpG-ODN/Coa-ASC16 elicited a potent specific IgG1, IgG2a, Th1 and Th17 cellular response without systemic adverse effects. These responses were superior to those induced by OVA/CpG-ODN (solution of OVA with CpG-ODN) and to those induced by the formulation OVA/CpG-ODN/Al(OH)3. Immunization with OVA/CpG-ODN/Coa-ASC16 resulted in a long-lasting cell-mediated immune response (at least 6.5 months). Furthermore, Coa-ASC16 alone allows a controlled release of CpG-ODN in vitro and induces local inflammatory response, independent of TLR4 signaling, characterized by an influx of neutrophils and Ly6C(high) monocytes and pro-inflammatory cytokines. Remarkably, the adjuvant capacity of CpG-ODN co-injected with Coa-ASC16 (OVA/CpG-ODN plus Coa-ASC16) was similar to the adjuvant activity of OVA/CpG-ODN, supporting the requirement for whole formulation to help CpG-ODN adjuvanticity. These results show the potential of this formulation, opening a new avenue for the development of better vaccines.