RESUMEN

Bio-inspired nanotechnology-based strategies are potential platforms for enhanced dissolution and oral biovailability of poorly water-soluble drugs. In this study, a recently patented green biopolymer (Prosopis africana gum, PG) was compatibilized with microcrystalline cellulose (MCC), a conventional polysaccharide, via thermo-regulated coacervation to obtain PG-MCC (1:0, 1:1, 1:2, 2:1, and 0:1) rational blends and the nanoparticles developed with optimized (1:1) biocomposites (termed "prosopisylated cellulose") by combined homogenization-nanoprecipitation technique was engineered as a high circulating system for improved oral bioavailability of griseofulvin (GF), a model Biopharmaceutics Classification System (BCS) Class-II drug. The effects of biopolymer interaction on morphological and microstructural properties of drug-free biocomposites obtained were investigated by Fourier transform infra-red spectroscopy, scanning electron microscopy and x-ray diffractometry, while the physicochemical properties and in-vivo pharmacokinetics of GF-loaded nanoparticles were also ascertained. Optimized biocomposites revealed inter-molecular and intra-molecular hydrogen bonding between the hydroxyl group of MCC and polar components of PG, as well as reduction in crystallinity of MCC. Griseofulvin-loaded nanoparticles were stable, displayed particles with relatively smooth surfaces and average size of 26.18 ± 0.94 . nm, with zeta potential and polydispersity index of 32.1 ± 0.57 mV and 0.173 ± 0.06, respectively. Additionally, the nanoparticles showed good entrapment efficiency (86.51 ± 0.93 %), and marked improvement in griseofulvin dissolution when compared to free drug, with significantly (p < 0.05) higher GF release in basic than acidic PEG-reinforced simulated bio-microenvironments. Besides, x-ray diffractogram of GF-loaded nanoparticles showed amorphization with few characteristic peaks of GF while infra-red spectrum indicated broader principal peaks of GF and components compatibility. Furthermore, GF-loaded nanoparticles showed low plasma clearance with three-fold increase in systemic bioavailability of griseofulvin compared with free drug. These results showed that prosopisylated cellulose nanoparticles would be a facile approach to improve oral bioavailability of BCS class-II drugs and can be pursued as a new versatile drug delivery platform.

Asunto(s)

Administración Oral , Materiales Biocompatibles/química , Celulosa/química , Nanopartículas/química , Solubilidad , Agua/química , Animales , Disponibilidad Biológica , Tampones (Química) , Portadores de Fármacos/química , Composición de Medicamentos , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Femenino , Griseofulvina/química , Enlace de Hidrógeno , Concentración de Iones de Hidrógeno , Masculino , Nanotecnología/métodos , Tamaño de la Partícula , Conejos

RESUMEN

Human activities in the areas of high altitude have increased significantly recently. Brain is highly sensitive to changing of oxygen pressure due to high altitude, and this physiological response may lead to serious brain injury, such as learning and memory disabilities. Puerarin is a phytoestrogen with many pharmacological activities, such as treatment of neurological disorders. However, most of current drugs can not easily enter brain through the blood-brain barrier (BBB). The nose-to-brain route can bypass BBB for brain-targeting. Here, thermosensitive in situ hydrogels (TISGs) of puerarin were prepared with poloxamers 407, poloxamers 188 and propylene glycol to improve bioavailability and brain targeting. In vitro drug release in simulated nasal fluids, rheological properties and cilia toxicity of puerarin TISGs were explored. The pharmacodynamics and pharmacokinetics of puerarin by intranasal (i.n.) and oral (p.o.) administrations were also evaluated. The viscosity of puerarin TISGs tended to increase obviously with increased temperature. The puerarin release profile and transmucosal process of puerarin TISGs could be described with the first-order kinetics equation, depending on drug diffusion. The cilia toxicity of puerarin TISGs was not obvious. Rat models of hypobarism/hypoxia-induced brain injury were established with a hypobaric simulation chamber. Morris water maze and open filed tests indicated that puerarin TISGs improved the spatial memory and spontaneous exploratory behavior of the rats suffering from hypoxia-induced brain injury. Furthermore, puerarin TISGs decreased the level of oxidative stress cytokines (malondialdehyde (MDA) and glutathione (GSH)) in the peripheral circulation, alleviated the cerebral histological lesions, and relieved the expression of hypoxia-inducible factor-1α (HIF-1α). Intranasal puerarin TISGs were absorbed quickly with a shorter Tmax (10.0 ± 5.7 min) compared to that of oral puerarin (36 ± 13.4 min). In addition, the relative bioavailability of i.n. puerarin TISGs was high to 300% compared to oral administration of puerarin. The area under the curve (AUC) of brain after i.n. administration of puerarin TISGs was 954.5 ± 335.1 h.ng/mL, while no puerarin was detected in the brain after oral administration. Therefore, i.n. puerarin TISGs led to excellent brain targeting effect. Puerarin TISGs are an effective neuroprotector formulation for prevention of brain injury induced by acute high-altitude hypoxia.

Asunto(s)

Mal de Altura , Lesiones Encefálicas , Administración Intranasal , Animales , Lesiones Encefálicas/tratamiento farmacológico , Hipoxia , Isoflavonas , Ratas

RESUMEN

The purpose of the present study was to determine the solubility of raloxifene hydrochloride (RHCl) in ten solvents: water, ethanol, isopropyl alcohol (IPA), ethylene glycol (EG), propylene glycol (PG), polyethylene glycol-400 (PEG-400), Transcutol, 1-butanol, dimethyl sulfoxide (DMSO), and ethyl acetate (EA) at temperatures of 298.2-323.2 K and a pressure of 0.1 MPa. The solubility data obtained was fitted upon "Apelblat and Van't Hoff" equations. The maximum mole fraction solubility of RHCl was obtained in DMSO (5.02 × 10-2 at 323.2 K), followed by PEG-400 (5.92 × 10-3 at 323.2 K), EA (3.11 × 10-3 at 323.2 K), Transcutol (1.22 × 10-3 at 323.2 K), PG (2.19 × 10-4 at 323.2 K), 1-butanol (1.96 × 10-4 at 323.2 K), IPA (1.47 × 10-4 at 323.2 K), ethanol (7.90 × 10-5 at 323.2 K), EG (6.65 × 10-5 at 323.2 K), and water (3.60 × 10-5 at 323.2 K). Similar fashions were noticed at each studied temperature. The higher solubility of RHCl in DMSO, PEG-400, EA, and Transcutol was possibly referable to their lower polarity in comparison with water. The molecular interactions between the solute and solvent molecules were estimated by calculating parameters like activity coefficients, and more prominent solute-solvent molecular interactions were noted for RHCl-DMSO, RHCl-EA, and RHCl-PEG-400 in comparison with the other solute-solvent combinations. The outcomes of the "apparent thermodynamic analysis" showed that the dissolution of RHCl was "endothermic, spontaneous and entropy-driven" in all investigated solvents. The obtained solubility data of RHCl in commonly used solvents could be useful in the purification, recrystallization, and dosage form design of the drug.

Asunto(s)

Antagonistas de Estrógenos/química , Clorhidrato de Raloxifeno/química , Solventes/química , Difracción de Polvo , Solubilidad , Temperatura , Termodinámica , Difracción de Rayos X

RESUMEN

Autophagy is a cell survival mechanism hijacked by advanced tumors to endure a rough microenvironment. Late autophagy inhibitors such as (hydroxy)chloroquine have been used clinically to halt tumor progression with modest success. However, given the toxic nature of these compounds and their lack of specificity, novel targets should be considered. We recently identified a benzotropolone derivative that significantly inhibited the essential autophagy protein ATG4B. Therefore, we synthesized and tested additional benzotropolone compounds to identify a promising ATG4B inhibitor that impairs autophagy both in vitro and in vivo. A compound library containing 27 molecules with a benzotropolone backbone was synthesized and screened for inhibition of recombinant ATG4B. Depending on the benzotropolone compound, inhibition of recombinant ATG4B ranged from 3 to 82%. Active compounds were evaluated in cellular assays to confirm inhibition of ATG4B and suppression of autophagy. Seven compounds inhibited processing of the autophagy protein LC3 and autophagosome formation. Compound UAMC-2526 was selected for further in vivo use because of its fair plasma stability. This compound abolished autophagy both in nutrient-deprived GFP-LC3 mice and in CD1-/- Foxn1nu mice bearing HT29 colorectal tumor xenografts. Moreover, addition of UAMC-2526 to the chemotherapy drug oxaliplatin significantly improved inhibition of tumor growth. Our data indicate that suppression of autophagy via ATG4B inhibition is a feasible strategy to augment existing chemotherapy efficacy and to halt tumor progression.

Asunto(s)

Adenocarcinoma/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Proteínas Relacionadas con la Autofagia/antagonistas & inhibidores , Autofagia/efectos de los fármacos , Neoplasias del Colon/tratamiento farmacológico , Inhibidores de Cisteína Proteinasa/uso terapéutico , Diseño de Fármacos , Tropolona/análogos & derivados , Adenocarcinoma/patología , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Proteínas Relacionadas con la Autofagia/genética , Proteínas Relacionadas con la Autofagia/metabolismo , Proliferación Celular/efectos de los fármacos , Neoplasias del Colon/patología , Cisteína Endopeptidasas/genética , Cisteína Endopeptidasas/metabolismo , Inhibidores de Cisteína Proteinasa/química , Inhibidores de Cisteína Proteinasa/farmacología , Estabilidad de Medicamentos , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Células HEK293 , Células HT29 , Humanos , Células Jurkat , Ratones Noqueados , Ratones Transgénicos , Proteínas Asociadas a Microtúbulos/antagonistas & inhibidores , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Compuestos Organoplatinos/uso terapéutico , Oxaliplatino , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Tropolona/química , Tropolona/farmacología , Tropolona/uso terapéutico , Ensayos Antitumor por Modelo de Xenoinjerto

RESUMEN

Parameters of headspace solid-phase microextraction, such as fiber coating (85µm CAR/PDMS), extraction time (2min for white and 3min for red wines), temperature (85°C), pre-incubation time (15min) were optimized for identification and quantification of semi-volatile additives (propylene glycol, sorbic and benzoic acids) in wines. To overcome problems in their determination, an evaporation of the wine matrix was performed. Using the optimized method, screening of 25 wine samples was performed, and the presence of propylene glycol, sorbic and benzoic acids was found in 22, 20 and 6 samples, respectively. Analysis of different wines using a standard addition approach showed good linearity in concentration ranges 0-250, 0-125, and 0-250mg/L for propylene glycol, sorbic and benzoic acids, respectively. The proposed method can be recommended for quality control of wine and disclosing adulterated samples.

Asunto(s)

Benzoatos/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Propilenglicol/análisis , Microextracción en Fase Sólida/métodos , Ácido Sórbico/análisis , Vino/análisis

RESUMEN

Drug permeation through the intercellular lipids, which pack around and between corneocytes, may be enhanced by increasing the thermodynamic activity of the active in a formulation. However, this may also result in unwanted drug crystallisation on and in the skin. In this work, we explore the combination of ATR-FTIR spectroscopy and multivariate data analysis to study drug crystallisation in the skin. Ex vivo permeation studies of saturated solutions of diclofenac sodium (DF Na) in two vehicles, propylene glycol (PG) and dimethyl sulphoxide (DMSO), were carried out in porcine ear skin. Tape stripping and ATR-FTIR spectroscopy were conducted simultaneously to collect spectral data as a function of skin depth. Multivariate data analysis was applied to visualise and categorise the spectral data in the region of interest (1700-1500cm-1) containing the carboxylate (COO-) asymmetric stretching vibrations of DF Na. Spectral data showed the redshifts of the COO- asymmetric stretching vibrations for DF Na in the solution compared with solid drug. Similar shifts were evident following application of saturated solutions of DF Na to porcine skin samples. Multivariate data analysis categorised the spectral data based on the spectral differences and drug crystallisation was found to be confined to the upper layers of the skin. This proof-of-concept study highlights the utility of ATR-FTIR spectroscopy in combination with multivariate data analysis as a simple and rapid approach in the investigation of drug deposition in the skin. The approach described here will be extended to the study of other actives for topical application to the skin.

Asunto(s)

Diclofenaco/química , Epidermis/efectos de los fármacos , Piel/efectos de los fármacos , Espectroscopía Infrarroja por Transformada de Fourier , Animales , Antiinflamatorios no Esteroideos/química , Cromatografía Líquida de Alta Presión , Análisis por Conglomerados , Cristalización , Dimetilsulfóxido/química , Inflamación , Luz , Análisis Multivariante , Dolor , Análisis de Componente Principal , Propilenglicol/química , Porcinos , Termodinámica

RESUMEN

Convective flow is one of the main mechanisms of mass transfer employed in drug delivery (e.g. osmotic pumps) and working in material transport in the body (e.g. blood circulation). Although convective flow has been investigated extensively, not much data is available on convective behavior of nanoparticles, the subject of the present investigation. Here, liposomes with different sizes, charges, bilayer flexibilities and medium viscosities were encountered convective flow and changes in their properties were monitored over 48h. For large particles (>350nm), neutral liposomes (NL) showed significant phase separation and decreased lipid content over time, while positively or negatively charged liposomes remained homogenous. Reduction of size in NLs to about 100nm resolved phase separation problem, but their lipid content still showed reduction; no such a problem was observed in charged small liposomes. When bilayer flexibility of large NLs was increased, neither phase separation nor decreased lipid content was observed. Increasing medium viscosity for large NLs from 3.4cP to 45.2cP again solved the problem and a uniform liposomal delivery was observed. These results indicate that size, charge, bilayer flexibility and viscosity affect convective liposomal delivery and that uniform delivery is possible even in large liposomes by optimizing such factors.

Asunto(s)

Química Farmacéutica/métodos , Sistemas de Liberación de Medicamentos , Lípidos/química , Nanopartículas , Liposomas , Tamaño de la Partícula , Viscosidad

RESUMEN

Lycopene is a potent antioxidant that has received extensive attention recently. Due to the challenges encountered with current methods of lycopene extraction using hazardous solvents, industry calls for a greener, safer and more efficient process. The main purpose of present study was application of microemulsion technique to extract lycopene from tomato pomace. In this respect, the effect of eight different surfactants, four different co-surfactants, and ultrasound and enzyme pretreatments on lycopene extraction efficiency was examined. Experimental results revealed that application of combined ultrasound and enzyme pretreatments, saponin as a natural surfactant, and glycerol as a co-surfactant, in the bicontinuous region of microemulsion was the optimal experimental conditions resulting in a microemulsion containing 409.68±0.68 µg/glycopene. The high lycopene concentration achieved, indicates that microemulsion technique, using a low-cost natural surfactant could be promising for a simple and safe separation of lycopene from tomato pomace and possibly from tomato industrial wastes.

Asunto(s)

Carotenoides/aislamiento & purificación , Solanum lycopersicum/química , Tensoactivos/farmacología , Antioxidantes , Emulsiones , Residuos Industriales/análisis , Licopeno

RESUMEN

Self-nanoemulsifying formulations (SNEFs) structured with PEG 4000 as PEGylated SNEFs, were formulated after solubility studies using rational blends of soybean oil, a combination of Kolliphor(®) EL and Kolliphor(®) P188 as surfactants, and Transcutol(®) HP as co-surfactant, and evaluated for oral delivery of gentamicin. Incorporation of gentamicin and PEG 4000 reduced the initial area of nanoemulsion of the ternary phase diagrams produced by water titration method using oil, surfactant mixture and co-surfactant. Emulsion droplets were in the nanometer scale ranging from 80-210 nm. FT-IR study revealed that gentamicin structure remained intact in all formulations, and SEM micrographs showed spherical globules. Zeta potentials of SNEFs were in the range of -25.4 to -42.5 mV, and showed a stable system with minor flips in electrostatic charges. There was high in vitro diffusion-dependent permeation of gentamicin from the SNEFs. Results obtained in this work showed that oral delivery of gentamicin was improved by formulation as surface modified SNEFs.

Asunto(s)

Química Farmacéutica/métodos , Emulsionantes/química , Emulsiones/química , Gentamicinas/química , Nanotecnología/métodos , Polietilenglicoles/química , Administración Oral , Cápsulas , Estabilidad de Medicamentos , Gentamicinas/administración & dosificación , Gentamicinas/farmacología , Pruebas de Sensibilidad Microbiana , Nanopartículas/química , Nanopartículas/ultraestructura , Tamaño de la Partícula , Permeabilidad , Transición de Fase/efectos de los fármacos , Solubilidad , Factores de Tiempo , Viscosidad

RESUMEN

The aim of the present work is the characterization of smart auto-degradable microspheres composed of calcium alginate/high methoxylated pectin containing an alginate lyase (AL) from Sphingobacterium multivorum and levofloxacin. Microspheres were prepared by ionotropic gelation containing AL in its inactive form at pH 4.0. Incubation of microspheres in Tris-HCl and PBS buffers at pH 7.40 allowed to establish the effect of ion-chelating phosphate on matrix erodability and suggested an intrinsically activation of AL by turning the pH close to neutrality. Scanning electron and optical microscopies revealed the presence of holes and surface changes in AL containing microspheres. Furthermore, texturometric parameters, DSC profiles and swelling properties were showing strong changes in microspheres properties. Encapsulation of levofloxacin into microspheres containing AL showed 70% efficiency and 35% enhancement of antimicrobial activity against Pseudomonas aeruginosa biofilm. Levofloxacin release from microspheres was not changed at acidic pH, but was modified at neutral pH in presence of AL. Advantageously, only gel matrix debris were detectable after overnight incubation, indicating an autodegradative gel process activated by the pH. Absence of matrix cytotoxicity and a reduction of the levofloxacin toxicity after encapsulation were observed in mammalian CHO-K1 cell cultures. These properties make the system a potent and versatile tool for antibiotic oral delivery targeted to intestine, enhancing the drug bioavailability to eradicate bacterial biofilm and avoiding possible intestinal obstructions.

Asunto(s)

Alginatos/química , Antibacterianos/administración & dosificación , Biopelículas/efectos de los fármacos , Sistemas de Liberación de Medicamentos , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Levofloxacino/administración & dosificación , Ácido Glucurónico/química , Ácidos Hexurónicos/química , Concentración de Iones de Hidrógeno , Levofloxacino/química , Levofloxacino/farmacología , Microesferas , Solubilidad

RESUMEN

Intranasal Microemulsions (MEs) for nose to brain delivery of a novel combination of Albendazole sulfoxide (ABZ-SO) and Curcumin (CUR) for Neurocysticercosis (NCC), a brain infection are reported. MEs prepared by simple solution exhibited a globule size <20nm, negative zeta potential and good stability. The docosahexaenoic acid (DHA) ME revealed high and rapid ex vivo permeation of drugs through sheep nasal mucosa. Intranasal DHA ME resulted in high brain concentrations and 10.76 (ABZ-SO) and 3.24 (CUR) fold enhancement in brain area-under-the-curve (AUC) compared to intravenous DHA MEs at the same dose. Direct nose to brain transport (DTP) of >95% was seen for both drugs. High drug targeting efficiency (DTE) to the brain compared to Capmul ME and drug solution (P<0.05) suggested the role of DHA in aiding nose to brain delivery. Histopathology study confirmed no significant changes. High efficacy of ABZ-SO: CUR (100:10ng/mL) DHA ME in vitro on Taenia solium cysts was confirmed by complete ALP inhibition and disintegration of cysts at 96h. Considering that the brain concentration at 24h was 1400±160.1ng/g (ABZ-SO) and 120±35.2ng/g (CUR), the in vitro efficacy seen at a 10 fold lower concentration of the drugs strongly supports the assumption of clinical efficacy. The intranasal DHA ME is a promising delivery system for targeted nose to brain delivery.

Asunto(s)

Albendazol/análogos & derivados , Antihelmínticos/administración & dosificación , Antiinflamatorios no Esteroideos/administración & dosificación , Barrera Hematoencefálica/efectos de los fármacos , Curcumina/administración & dosificación , Ácidos Docosahexaenoicos/química , Sistemas de Liberación de Medicamentos , Administración Intranasal , Albendazol/administración & dosificación , Albendazol/química , Albendazol/metabolismo , Albendazol/farmacocinética , Animales , Antihelmínticos/química , Antihelmínticos/metabolismo , Antihelmínticos/farmacocinética , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/metabolismo , Antiinflamatorios no Esteroideos/farmacocinética , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/ultraestructura , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Curcumina/química , Curcumina/metabolismo , Curcumina/farmacocinética , Combinación de Medicamentos , Composición de Medicamentos , Estabilidad de Medicamentos , Emulsiones , Femenino , Técnicas In Vitro , Masculino , Absorción Nasal , Neurocisticercosis/sangre , Neurocisticercosis/tratamiento farmacológico , Neurocisticercosis/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Vehículos Farmacéuticos/química , Ratas Sprague-Dawley , Oveja Doméstica , Distribución Tisular

RESUMEN

This paper put forward a deconvolution-based method for designing and optimizing tanshinone IIA sustained-release pellets (TA-SRPs) with improved efficacy in the treatment of variant angina. TA-SRPs were prepared by coating TA ternary solid dispersion immediate-release pellets (TA-tSD-IRPs) with the blends of polyvinyl acetate (PVAc) and polyvinyl alcohol-polyethylene glycol (PVA-PEG) using fluidized bed technology. The plasma concentration-time curve of TA-tSD-IRPs following oral administration as a weight function was investigated in New Zealand white rabbits. The predicted/expected plasma concentration-time curve of TA-SRPs as a response function was simulated according to the circadian rhythm of variant angina during 24h based on chronotherapy theory. The desired drug release profile of TA-SRPs was obtained via the point-area deconvolution procedure using the weight function and response function, and used for formulation optimization of TA-SRPs. The coating formulation of TA-SRPs was optimized as 70:30 (w/w) PVAc/PVA-PEG with 5% (w/w) coating weight due to in vitro drug release profile of these TA-SRPs was similar to the desired release profile (similarity factor f2=64.90). Pharmacokinetic studies of these optimized TA-SRPs validated that their actual plasma concentration-time curve possessed a basically consistent trend with the predicted plasma concentration-time curve and the absolute percent errors (%PE) of concentrations in 8-12h were less than 10%. Pharmacodynamic studies further demonstrated that these TA-SRPs had stable and improved efficacy with almost simultaneous drug concentration-efficacy. In conclusion, deconvolution could be employed in the development of TA-SRPs for angina chronotherapy with simultaneous drug efficacy and reduced design blindness and complexity.

Asunto(s)

Abietanos/administración & dosificación , Abietanos/farmacocinética , Angina de Pecho/tratamiento farmacológico , Fármacos Cardiovasculares/administración & dosificación , Fármacos Cardiovasculares/farmacocinética , Cronoterapia de Medicamentos , Tecnología Farmacéutica/métodos , Abietanos/sangre , Abietanos/química , Administración Oral , Angina de Pecho/sangre , Animales , Fármacos Cardiovasculares/sangre , Fármacos Cardiovasculares/química , Química Farmacéutica , Simulación por Computador , Preparaciones de Acción Retardada , Modelos Animales de Enfermedad , Excipientes/química , Masculino , Modelos Biológicos , Óxido Nítrico/sangre , Polietilenglicoles/química , Alcohol Polivinílico/química , Polivinilos/química , Conejos , Solubilidad

RESUMEN

Although leukotrienes have been implicated in seizures, no study has systematically investigated whether the blockade of CysLT1 receptors synergistically increases the anticonvulsant action of classic antiepileptics. In this study, behavioral and electroencephalographic methods, as well as isobolographic analysis, are used to show that the CysLT1 inverse agonist montelukast synergistically increases the anticonvulsant action of phenobarbital against pentylenetetrazole-induced seizures. Moreover, it is shown that LTD4 reverses the effect of montelukast. The experimentally derived ED50mix value for a fixed-ratio combination (1:1 proportion) of montelukast plus phenobarbital was 0.06±0.02 µmol, whereas the additively calculated ED50add value was 0.49±0.03 µmol. The calculated interaction index was 0.12, indicating a synergistic interaction. The association of montelukast significantly decreased the antiseizure ED50 for phenobarbital (0.74 and 0.04 µmol in the absence and presence of montelukast, respectively) and, consequently, phenobarbital-induced sedation at equieffective doses. The demonstration of a strong synergism between montelukast and phenobarbital is particularly relevant because both drugs are already used in the clinics, foreseeing an immediate translational application for epileptic patients who have drug-resistant seizures.

Asunto(s)

Acetatos/farmacología , Anticonvulsivantes/farmacología , Antagonistas de Leucotrieno/farmacología , Fenobarbital/farmacología , Quinolinas/farmacología , Animales , Convulsivantes , Ciclopropanos , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Electroencefalografía/efectos de los fármacos , Femenino , Ratones , Actividad Motora/efectos de los fármacos , Pentilenotetrazol , Convulsiones/inducido químicamente , Convulsiones/prevención & control , Sulfuros

RESUMEN

RNA-cleaving DNAzymes are a potential novel class of nucleic acid-based active pharmaceutical ingredients (API). However, developing an appropriate drug delivery system (DDS) that achieves high bioavailability is challenging. Especially in a dermal application, DNAzymes have to overcome physiological barriers composed of penetration barriers and degrading enzymes. The focus of the present study was the development of a protective and penetration-enhanced dermal DDS that was tailor made for DNAzymes. DNAzyme Dz13 was used as a potential API for topical therapy against actinic keratosis. In the progress of development and selection, different preservatives, submicron emulsions (SMEs) and the physiological pH range were validated with respect to the API's integrity. A physicochemical stable SME of a pharmaceutical grade along with a high API integrity was achieved. Additionally, two developed protective systems, consisting of a liposomal formulation or chitosan-polyplexes, reduced the degradation of Dz13 in vitro. A combination of SME and polyplexes was finally validated at the skin and cellular level by in vitro model systems. Properties of penetration, degradation and distribution were determined. The result was enhanced skin penetration efficiency and increased cellular uptake with a high protective efficiency for DNAzymes due to the developed protective DDS.

Asunto(s)

ADN Catalítico/administración & dosificación , Sistemas de Liberación de Medicamentos , Administración Cutánea , Animales , Línea Celular , Quitosano/química , Citoplasma/metabolismo , ADN Catalítico/química , ADN Catalítico/farmacología , Estabilidad de Enzimas , Humanos , Técnicas In Vitro , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Queratosis Actínica , Liposomas , Piel/metabolismo , Absorción Cutánea , Sus scrofa

RESUMEN

Therapeutics based on short interfering RNAs (siRNAs), which act by inhibiting the expression of target transcripts, represent a novel class of potent and highly specific next-generation treatments for human skin diseases. Unfortunately, the intrinsic barrier properties of the skin combined with the large size and negative charge of siRNAs make epidermal delivery of these macromolecules quite challenging. To help evaluate the in vivo activity of these therapeutics and refine delivery strategies we generated an innovative reporter mouse model that predominantly expresses firefly luciferase (luc2p) in the paw epidermis--the region of murine epidermis that most closely models the tissue architecture of human skin. Combining this animal model with state-of-the-art live animal imaging techniques, we have developed a real-time in vivo analysis work-flow that has allowed us to compare and contrast the efficacies of a wide range nucleic acid-based gene silencing reagents in the skin of live animals. While inhibition was achieved with all of the reagents tested, only the commercially available "self-delivery" modified Accell-siRNAs (Dharmacon) produced potent and sustained in vivo gene silencing. Together, these findings highlight just how informative reliable reporter mouse models can be when assessing novel therapeutics in vivo. Using this work-flow, we developed a novel clinically-relevant topical formulation that facilitates non-invasive epidermal delivery of unmodified and "self-delivery" siRNAs. Remarkably, a sustained >40% luc2p inhibition was observed after two 1-hour treatments with Accell-siRNAs in our topical formulation. Importantly, our ability to successfully deliver siRNA molecules topically brings these novel RNAi-based therapeutics one-step closer to clinical use.

Asunto(s)

Silenciador del Gen , Terapia Genética/métodos , ARN Interferente Pequeño/uso terapéutico , Administración Tópica , Animales , Química Farmacéutica , Sistemas de Liberación de Medicamentos , Epidermis/efectos de los fármacos , Proteínas Filagrina , Genes Reporteros/efectos de los fármacos , Humanos , Inyecciones Intradérmicas , Proteínas de Filamentos Intermediarios/administración & dosificación , Proteínas de Filamentos Intermediarios/genética , Ratones , ARN Interferente Pequeño/administración & dosificación

RESUMEN

2,4-Dichlorophenoxy acetic acid (2,4-D) is a well-known plant auxin which is widely used in plant tissue culture experiments as well as a weed killer and a herbicide. In this study, 2,4-D was rediscovered as a new anti-inflammatory agent through an in silico molecular modeling and docking studies along with drug formulation and in vivo anti-inflammatory inspection. The molecular modeling and docking studies indicated high affinity of 2,4-D toward COX-2 enzyme in a way similar to Ibuprofen, suggesting a higher anti-inflammatory activity. Molecular docking by both MOE 2013.08 and Leadit 2.1.2 revealed excellent binding pattern compared to some of well-known non-steroidal anti-inflammatory drugs. 2,4-D was formulated in different gel bases. In vitro drug release experiments were used to examine the best 2,4-D formula for in vivo studies. In vivo carrageenan-induced hind paw edema inflammatory model in rats was used to test the in silico finding. 2,4-D showed potential in vivo anti-inflammatory activity and significantly reduced the concentration of prostaglandin E2 in hind paw tissues in a way similar to Ibuprofen. These results may open the door to introduce a new anti-inflammatory molecule; especially that 2,4-D is a well-investigated regarding its toxicity and side effect.

Asunto(s)

Ácido 2,4-Diclorofenoxiacético/química , Ácido 2,4-Diclorofenoxiacético/farmacología , Antiinflamatorios/química , Antiinflamatorios/farmacología , Animales , Carragenina/farmacología , Química Farmacéutica/métodos , Ciclooxigenasa 2/metabolismo , Dinoprostona/metabolismo , Reposicionamiento de Medicamentos/métodos , Edema/tratamiento farmacológico , Edema/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Masculino , Ratas , Ratas Wistar

RESUMEN

After use in oral pharmaceutical products, nanocrystals are meanwhile applied to improve the dermal penetration of cosmetic actives (e.g. rutin, hesperidin) and of drugs. By now, nanocrystals are only dermally applied made from poorly soluble actives. The novel concept is to formulate nanocrystals also from medium soluble actives, and to apply a dermal formulation containing additionally nanocrystals. The nanocrystals should act as fast dissolving depot, increase saturation solubility and especially accumulate in the hair follicles, to further increase skin penetration. Caffeine was used as model compound with relevance to market products, and a particular process was developed for the production of caffeine nanocrystals to overcome the supersaturation related effect of crystal growth and fiber formation - typical with medium soluble compounds. It is based on low energy milling (pearl milling) in combination with low dielectric constant dispersion media (water-ethanol or ethanol-propylene glycol mixtures) and optimal stabilizers. Most successful was Carbopol(®) 981 (e.g. 20% caffeine in ethanol-propylene glycol 3:7 with 2% Carbopol, w/w). Nanocrystals with varied sizes can now be produced in a controlled process e.g. 660 nm (optimal for hair follicle accumulation) to 250 nm (optimal for fast dissolution). The short term test proved stability over 2 months of the present formulation being sufficient to perform in vivo testing of the novel concept.

Asunto(s)

Cafeína/química , Portadores de Fármacos/química , Nanopartículas/química , Resinas Acrílicas/química , Administración Cutánea , Cafeína/administración & dosificación , Cafeína/farmacocinética , Química Farmacéutica , Cosméticos , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/farmacocinética , Composición de Medicamentos , Folículo Piloso/química , Nanopartículas/administración & dosificación , Absorción Cutánea , Solubilidad

RESUMEN

The aim of this work was to develop a fast-dissolving film formulation containing EFdA for potential use as a topical vaginal microbicide for prevention of HIV sexual transmission. Solid state compatibility approaches were used to screen commonly used polymers for formulation development. Factorial design and desirability function were used to investigate the effect of two variables, the ratio of the polymers and the concentration of selected plasticizer on four mechanical responses including tensile strength, elongation at break, toughness and elastic modulus for optimization of the film formulation. Assessments of EFdA-loaded films included physicochemical characteristics, in vitro cytotoxicity, epithelia integrity, ex vivo permeability and bioactivity test. The optimal placebo film was composed of PVA, HPMC E5 and propylene glycol (7:3:3, w/w), and its mechanical characteristics were comparable to those of VCF(®) film (a commercial vaginal film product). Permeability studies using human ectocervical explants showed that there was no significant difference in cumulative permeated amount of EFdA between EFdA film and free EFdA. The results of in vitro cytotoxicity and bioactivity testing showed that 50% cytotoxic concentration (CC50) was several orders of magnitude higher than 50% effective concentration (EC50) of EFdA. Furthermore, epithelial integrity study showed that EFdA-loaded film had a much lower toxicity to HEC-1A cell monolayers as compared to VCF(®). Therefore, EFdA-loaded vaginal film may be considered as a promising vaginal microbicide for HIV prevention.

Asunto(s)

Desoxiadenosinas/administración & dosificación , Excipientes/química , Infecciones por VIH/prevención & control , Inhibidores de la Transcriptasa Inversa/administración & dosificación , Administración Intravaginal , Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/farmacología , Fármacos Anti-VIH/toxicidad , Línea Celular , Química Farmacéutica/métodos , Desoxiadenosinas/farmacología , Desoxiadenosinas/toxicidad , Relación Dosis-Respuesta a Droga , Composición de Medicamentos , Femenino , Humanos , Persona de Mediana Edad , Permeabilidad , Plastificantes/química , Polímeros/química , Inhibidores de la Transcriptasa Inversa/farmacología , Inhibidores de la Transcriptasa Inversa/toxicidad , Solubilidad , Factores de Tiempo