RESUMO
In this article, the degradability by Aspergillus niger and Aspergillus clavatus of three bio-based polyurethane (PU) foams is compared to previous degradability studies involving a Pseudomonas sp. bacterium and similar initial materials (Spontón et al. in Int. Biodet. Biodeg. 85:85-94, 2013, https://doi.org/10.1016/j.ibiod.2013.05.019 ). First, three new polyester-polyurethane foams were prepared from mixtures of castor oil (CO), maleated castor oil (MACO), toluene diisocyanate (TDI), and water. Then, their degradation tests were carried out in an aqueous medium, and employing the two mentioned fungi, after their isolation from the environment. From the degradation tests, the following was observed: (a) the insoluble (and slightly collapsed) foams exhibited free hydroxyl, carboxyl, and amine moieties; and (b) the water soluble (and low molar mass) compounds contained amines, carboxylic acids, and glycerol. The most degraded foam contained the highest amount of MACO, and therefore the highest concentration of hydrolytic bonds. A basic biodegradation mechanism was proposed that involves hydrolysis and oxidation reactions.
Assuntos
Aspergillus , Poliésteres , Poliuretanos , Poliuretanos/química , Poliuretanos/metabolismo , Poliésteres/metabolismo , Aspergillus niger/metabolismo , Óleo de Rícino/química , ÁguaRESUMO
In previous work, we identified a triple mutant of the castor (Ricinus communis) stearoyl-Acyl Carrier Protein desaturase (T117R/G188L/D280K) that, in addition to introducing a double bond into stearate to produce oleate, performed an additional round of oxidation to convert oleate to a trans allylic alcohol acid. To determine the contributions of each mutation, in this work we generated individual castor desaturase mutants carrying residue changes corresponding to those in the triple mutant and investigated their catalytic activities. We observed that T117R, and to a lesser extent D280K, accumulated a novel product, namely erythro-9,10-dihydroxystearate, that we identified via its methyl ester through gas chromatography-mass spectrometry and comparison with authentic standards. The use of 18O2 labeling showed that the oxygens of both hydroxyl moieties originate from molecular oxygen rather than water. Incubation with an equimolar mixture of 18O2 and 16O2 demonstrated that both hydroxyl oxygens originate from a single molecule of O2, proving the product is the result of dioxygenase catalysis. Using prolonged incubation, we discovered that wild-type castor desaturase is also capable of forming erythro-9,10-dihydroxystearate, which presents a likely explanation for its accumulation to â¼0.7% in castor oil, the biosynthetic origin of which had remained enigmatic for decades. In summary, the findings presented here expand the documented constellation of di-iron enzyme catalysis to include a dioxygenase reactivity in which an unactivated alkene is converted to a vicinal diol.
Assuntos
Dioxigenases/metabolismo , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Ricinus/enzimologia , Ácidos Esteáricos/metabolismo , Óleo de Rícino/química , Catálise , Dioxigenases/química , Cromatografia Gasosa-Espectrometria de Massas , Oxigenases de Função Mista/química , Mutação , Ácido Oleico/química , Ácido Oleico/metabolismo , Oxirredução , Oxigênio/metabolismo , Propanóis/metabolismo , Ricinus/genética , Ricinus/metabolismo , Ácidos Esteáricos/químicaRESUMO
Biomaterials used in tissue regeneration processes represent a promising option for the versatility of its physical and chemical characteristics, allowing for assisting or speeding up the repair process stages. This research has characterized a polyurethane produced from castor oil monoacylglyceride (Ricinus communis L) and tested its effect on reconstructing bone defects in rat calvaria, comparing it with commercial castor oil polyurethane. The characterizations of the synthesized polyurethane have been performed by spectroscopy in the infrared region with Fourier transform (FTIR); thermogravimetric analysis (TG/DTG); X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). For the in vivo test, 24 animals have been used, divided into 3 groups: untreated group (UG); control group treated with Poliquil® castor polyurethane (PCP) and another group treated with castor polyurethane from the Federal University of Piauí - UFPI (CPU). Sixteen weeks after surgery, samples of the defects were collected for histological and histomorphometric analysis. FTIR analysis has shown the formation of monoacylglyceride and polyurethane. TG and DTG have indicated thermal stability of around 125 °C. XRD has determined the semi-crystallinity of the material. The polyurethane SEM has shown a smooth morphology with areas of recesses. Histological and histomorphometric analyzes have indicated that neither CPU nor PCP induced a significant inflammatory process, and CPU has shown, statistically, better performance in bone formation. The data obtained shows that CPU can be used in the future for bone reconstruction in the medical field.
Assuntos
Fraturas Ósseas/cirurgia , Monoglicerídeos/química , Poliuretanos/química , Ricinus/química , Animais , Materiais Biocompatíveis/química , Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/farmacologia , Osso e Ossos/metabolismo , Óleo de Rícino/química , Consolidação da Fratura , Inflamação , Masculino , Teste de Materiais , Microscopia Eletrônica de Varredura , Osteogênese/efeitos dos fármacos , Ratos , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Difração de Raios XRESUMO
(R)-ricinoleic acid is the main component of castor oil from Ricinus communis L. Due to the presence of the hydroxyl group in homoallylic position and asymmetrically substituted carbon atom, it may undergo a number of chemical and biochemical transformations resulting in the products with some specific bioactivities. Conversion of (R)-ricinoleic acid into its (S)-enantiomer enables synthesis of both (R)- and (S)-ricinoleic acid derivatives and comparison of their biological activities. In the present research, (R)- and (S)-ricinoleic acid amides synthesized from methyl ricinoleates and ethanolamine or pyrrolidine as well as acetate derivatives of ethanolamine amides were studied to demonstrate their biological activities using HT29 cancer cells. Double staining of cells with fluorochromes (Hoechst 33258/propidium iodide) as well as 2,'7'-dichlorodihydrofluorescein (DCF) and comet assays were performed. Both the tested amides and acetates caused DNA damage and induced apoptotic and necrotic cell death. In the case of (R)- and (S)-enantiomers of one of the tested acetates, significant difference in the ability to induce DNA damage was observed, which showed the impact of the stereogenic center on the activities of these compounds.
Assuntos
Acetatos/química , Amidas/química , Antineoplásicos/farmacologia , Óleo de Rícino/química , Ácidos Ricinoleicos/química , Antineoplásicos/química , Dano ao DNA/efeitos dos fármacos , Células HT29 , Humanos , Ácidos Ricinoleicos/toxicidade , EstereoisomerismoRESUMO
In the present study, we report a reverse-phase high-performance liquid chromatography (RP-HPLC) method for separation of the regio-isomers of Glyceryl MonoRicinoleate (GMR) identified using position specificity of lipases. The approaches explored to identify these regio-isomers include LC-mass spectrometry, UV spectroscopy, and selective hydrolysis with lipases. A distinct UV absorption spectrum and λmax values for each isomer were noted, and mass spectral analysis further revealed their molecular weight. Lastly, the purified regio-isomers were subjected to hydrolysis with two distinctive regio-specific lipases to identified as sn-2 and sn-1(3) GMR. The current methodology of using analytic tool and enzyme specificity provides a useful platform for identifying regio-isomers for structured lipid synthesis.
Assuntos
Glicerídeos/análise , Lipase/química , Ácidos Ricinoleicos/análise , Óleo de Rícino/química , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Glicerídeos/química , Hidrólise , Isomerismo , Ácidos Ricinoleicos/química , Ricinus/químicaRESUMO
The present paper investigates the feasibility of using acetone (ACE) in triple blends with fossil diesel (D) and straight vegetable oils (SVOs) as alternative fuel for diesel engines. In this respect, ACE is selected as an oxygenated additivedue to its favorable propertiesto be mixed with vegetable oils and fossil diesel. In fact, the very low kinematic viscosity allows reduces the high viscosity of SVOs. ACE's oxygen content, low autoignition temperature, and very low cloud point and pour point values highlight its possibilities as an additive in D/ACE/SVO triple blends. Moreover, ACE can be produced through a renewable biotechnological process, an acetone-butanol-ethanol (ABE) fermentation from cellulosic biomass. The SVOs tested were castor oil (CO), which is not suitable for human consumption, and sunflower oil (SO), used as a standard reference for waste cooking oil. The viscosity measurement of the ACE/SVO double blend was considered crucial to choose the optimum proportion, which better fulfilled the specifications established by European standard EN 590. Moreover, some of the most significant physicochemical properties of D/ACE/SVO triple blends, such as kinematic viscosity, cloud point, pour point, and calorific value, were determined to assess their suitability as fuels. The blends were evaluated in a conventional diesel generator through the study of the following parameters: engine power, smoke emissions, and fuel consumption. Despite the low calorific value of ACE limits its ratio in the mixtures due to engine knocking problems, the experimental results reveal an excellent performance for the blends containing up to 16-18% of ACE and 22-24% of SVO. These blends produce similar engine power as to fossil diesel, but with slightly higher fuel consumption. Considerable reductions in emissions of air pollutants, as well as excellent cold flow properties are also obtained with these triple blends. In summary, the use of these biofuels could achieve a substitution of fossil diesel up to 40%, independently on the SVO employed.
Assuntos
Acetona/química , Biocombustíveis/análise , Óleo de Rícino/química , Gasolina/análise , Óleos de Plantas/química , Óleo de Girassol/química , Emissões de Veículos/análise , HumanosRESUMO
Pasty polymers offer a platform for injectable implants for drug delivery. A library of biodegradable pasty polymers was synthesized by bulk ring-opening polymerization of lactide, glycolide, trimethylene carbonate, or caprolactone using castor oil or 12-hydroxy stearic acid as hydroxyl initiators and stannous octoate as the catalyst. Some of the polymers behaved as Newtonian liquids. Pasty polymers of poly(caprolactone) and poly(trimethylene carbonate) were stable under physiologic conditions for over 1 month in vitro, whereas polymers of poly(lactic-co-glycolic acid) degraded within 10 days. These pasty polymers offer a platform for pasty injectable biodegradable carriers for drugs and fillers. SIGNIFICANCE STATEMENT: New injectable pasty, in situ forming drug delivery systems are described and are advantageous due to their ease of administration, tunable viscosity, and biodegradability. Polyesters based on lactide, glycolide, trimethylene carbonate, and caprolactone, which are commonly used as absorbable implants and drug carriers, were conjugated onto natural hydroxyl fatty acids. These polymers have potential use as wrinkle fillers and drug carriers.
Assuntos
Plásticos Biodegradáveis , Óleo de Rícino/química , Hidroxiácidos/química , Lactonas/química , Polímeros , Portadores de Fármacos , Stents Farmacológicos , Ácidos Graxos/química , Injeções , ViscosidadeRESUMO
Polyurethanes are widely used in the development of medical devices due to their biocompatibility, degradability, non-toxicity and chemical versatility. Polyurethanes were obtained from polyols derived from castor oil, and isophorone diisocyanate, with the incorporation of polycaprolactone-diol (15% w/w) and chitosan (3% w/w). The objective of this research was to evaluate the effect of the type of polyol and the incorporation of polycaprolactone-diol and chitosan on the mechanical and biological properties of the polyurethanes to identify the optimal ones for applications such as wound dressings or tissue engineering. Polyurethanes were characterized by stress-strain, contact angle by sessile drop method, thermogravimetric analysis, differential scanning calorimetry, water uptake and in vitro degradation by enzymatic processes. In vitro biological properties were evaluated by a 24 h cytotoxicity test using the colorimetric assay MTT and the LIVE/DEAD kit with cell line L-929 (mouse embryonic fibroblasts). In vitro evaluation of the possible inflammatory effect of polyurethane-based materials was evaluated by means of the expression of anti-inflammatory and proinflammatory cytokines expressed in a cellular model such as THP-1 cells by means of the MILLIPLEX® MAP kit. The modification of polyols derived from castor oil increases the mechanical properties of interest for a wide range of applications. The polyurethanes evaluated did not generate a cytotoxic effect on the evaluated cell line. The assessed polyurethanes are suggested as possible candidate biomaterials for wound dressings due to their improved mechanical properties and biocompatibility.
Assuntos
Óleo de Rícino/química , Quitosana/química , Poliésteres/química , Poliuretanos/síntese química , Animais , Fenômenos Biomecânicos , Varredura Diferencial de Calorimetria , Linhagem Celular , Proliferação de Células , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Teste de Materiais , Camundongos , Poliuretanos/química , Poliuretanos/farmacologia , Células THP-1/citologia , Células THP-1/efeitos dos fármacos , TermogravimetriaRESUMO
Despite the great potential of peptides as therapeutics, there is an unmet challenge in sustaining delivery of sufficient amounts in their native forms. This manuscript describes a novel nanocarrier capable of delivering functional small peptides in its native form. Self-assembling multi-layered nanomicelles composed of two polymers, polyoxyethylene hydrogenated castor oil 40 (HCO-40) and octoxynol 40 (OC-40), were designed to combine hydrophilic interaction and solvent-induced encapsulation of peptides and proteins. The polymers are employed to encapsulate peptide or protein in the core of the organo-nanomicelles which are further encapsulated with another layer of the same polymers to form an aqueous stable nanomicellar solution. The size of the multi-layered nanomicelles ranges from ~ 16 to 20 nm with zeta potential close to neutral (~ - 2.44 to 0.39 mV). In vitro release studies revealed that octreotide-loaded multi-layered nanomicelles released octreotide at much slower rate in simulated tear fluid (STF) (~ 27 days) compared to PBST (~ 11 days) in its native form. MTT assay demonstrated negligible toxicity of the multi-layered nanomicelles at lower concentrations in human retinal pigment epithelial (HRPE, D407), human conjunctival epithelial (CCL 20.2), and rhesus choroid-retinal endothelial (RF/6A) cells. This work demonstrates an efficient small peptide delivery platform with significant advantages over existing approaches, as it does not require modification of the peptide, is biodegradable, and has a small size and high loading capacity.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Micelas , Nanopartículas/administração & dosagem , Peptídeos/administração & dosagem , Epitélio Pigmentado da Retina/efeitos dos fármacos , Administração Oftálmica , Animais , Óleo de Rícino/administração & dosagem , Óleo de Rícino/química , Óleo de Rícino/metabolismo , Linhagem Celular , Humanos , Interações Hidrofóbicas e Hidrofílicas , Macaca mulatta , Nanopartículas/química , Nanopartículas/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Epitélio Pigmentado da Retina/metabolismoRESUMO
The pathophysiological mechanisms for dry and wet age-related macular degeneration (AMD) involve oxidative stress and increased VEGF release and expression. An ideal drug candidate for both types of AMD is the one which offers significant protection to the retinal cells from oxidative stress and inhibit VEGF release. Curcumin is one such natural product which provides numerous beneficial effects including antioxidant, anti-inflammatory, and anti-VEGF activities and has the potential for the treatment of both types of AMD. The bioavailability of curcumin is negligible due to its poor aqueous solubility. The purpose of this work is to develop an aqueous nanomicellar drop formulation of curcumin (CUR-NMF) for back of the eye delivery utilizing hydrogenated castor oil (HCO-40) and octoxynol-40 (OC-40) to treat AMD. A full factorial design was performed with JMP software analysis to optimize the formulation size, polydispersity index (PDI), entrapment efficiency, loading, and precipitation. MTT and LDH assays on human retinal pigmented epithelial (D407) cells revealed that 5-10 µM CUR-NMF dose is safe for ophthalmic use. Furthermore, CUR-NMF exhibited significant protection of retinal (D407) cells against H2O2-induced oxidative stress. In vitro drug release kinetics suggested a sustained drug release profile indicating a long-term protection ability of CUR-NMF against oxidative stress to retinal cells. In addition, an ELISA suggested that CUR-NMF significantly reduces vascular endothelial growth factor (VEGF) release in D407 cell line, hence diminishes the risk of angiogenesis. Collectively, these results suggest that the proposed CUR-NMF can be tremendously effective in treating both types of AMD.
Assuntos
Curcumina/administração & dosagem , Curcumina/farmacocinética , Olho/metabolismo , Micelas , Nanoestruturas , Administração Oftálmica , Antioxidantes/química , Disponibilidade Biológica , Óleo de Rícino/química , Linhagem Celular , Curcumina/farmacologia , Preparações de Ação Retardada , Humanos , Estresse Oxidativo/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
In the current study, we present the synthesis of novel low cost bio-polyurethane compositions with variable mechanical properties based on castor oil and glycerol for biomedical applications. A detailed investigation of the physicochemical properties of the polymer was carried out by using mechanical testing, ATR-FTIR, and X-ray photoelectron spectroscopy (XPS). Polymers were also tested in short term in-vitro cell culture with human mesenchymal stem cells to evaluate their biocompatibility for potential applications as biomaterial. FTIR analysis confirmed the synthesis of castor oil and glycerol based PU polymers. FTIR also showed that the addition of glycerol as co-polyol increases crosslinking within the polymer backbone hence enhancing the bulk mechanical properties of the polymer. XPS data showed that glycerol incorporation leads to an enrichment of oxidized organic species on the surface of the polymers. Preliminary investigation into in vitro biocompatibility showed that serum protein adsorption can be controlled by varying the glycerol content with polymer backbone. An alamar blue assay looking at the metabolic activity of the cells indicated that castor oil based PU and its variants containing glycerol are non-toxic to the cells. This study opens an avenue for using low cost bio-polyurethane based on castor oil and glycerol for biomedical applications.
Assuntos
Tecnologia Biomédica/economia , Biopolímeros/química , Óleo de Rícino/química , Custos e Análise de Custo , Glicerol/química , Poliuretanos/síntese química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Biopolímeros/economia , Óleo de Rícino/farmacologia , Forma Celular/efeitos dos fármacos , Reagentes de Ligações Cruzadas/química , Glicerol/farmacologia , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Espectroscopia Fotoeletrônica , Poliuretanos/economia , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de SuperfícieRESUMO
Different previous works have shown that various kinds of spheres can be manufactured by rotor granulation in a 'single-pot process' using a lipid base: hydrogenated castor oil. This single-pot technology is based on wet granulation where all components are placed in the powder form in the rotor bowl; then, they are continuously suspended in a fluidized air, with a tangentially sprayed liquid solution. This process allows the granulation and manufacturing of sphere during the same time. Previous experiments have studied the influence of the formulation and the manufacturing process parameters on spheres in terms of feasibility and dissolution properties. Both the spraying time and the weight of liquid sprayed were found to be the most relevant parameters that govern the final quality of the sphere. Now, in a second part of the work, a first comparison is made with two different fluid bed methods: the tangential rotor spray and the Wurster bottom spray for coating the lipid spheres previously manufactured with the rotor tangential spray. The external aspect of the coated spheres manufactured has been evaluated with an electronic microscopy analysis and a study of dissolution properties of the active ingredient has been done by USP in vitro dissolution tests.
Assuntos
Broncodilatadores/administração & dosagem , Óleo de Rícino/química , Composição de Medicamentos/métodos , Excipientes/química , Teofilina/administração & dosagem , Broncodilatadores/química , Preparações de Ação Retardada/química , Composição de Medicamentos/instrumentação , Desenho de Equipamento , Hidrogenação , Tamanho da Partícula , Propriedades de Superfície , Teofilina/químicaRESUMO
Oral dosage form has limited control over the release of drug from dosage form, hence effective plasma level concentration do not achieve at site of action. Such unusual pattern of dosing results in inappropriate or erratic blood plasma concentrations. The absorption of drug from conventional dosage form depends on factors such as-Physio-chemical properties of the drug, presence of excipient, physiological factors such as presence or absence of food, PH of the gastrointestinal tract etc. Present study highlights osmotically driven oral drug delivery system (tablet) containing celecoxib as an active ingredient. Patients with long term treatment of NSAID (e.g. Arthritis) and suffering from various gastrointestinal side effect will be benefited from such a dosage form. Majority of controlled release dosage forms available in market are generally matrix-based, their principal drug release mechanism was based on drug diffusion through the matrix. Such mechanism is changed by-the pH, presence of food, in the gastrointestinal tract. Body's physiological factors (G.I. motility) also contribute their role in unpredictable absorption. All these factors also affect the release of celecoxib from conventional oral dosage form. Osmotic systems utilize the principle of osmosis as delivery force to release the drug from the dosage form, and the release rate has no effect of the body's pH and other physiological factors, also the various side effects due to long term therapy of NSAIDs are reduced. Batch 6 coated with semipermeable membrane give the maximum of 90.28% release from elementary osmotic tablet in control manner up to 8 hours and following zero order release, other batches e.g. 4and 8 coated with microporous membrane follow first order release.
Assuntos
Celecoxib/química , Inibidores de Ciclo-Oxigenase 2/química , Administração Oral , Óleo de Rícino/química , Celecoxib/administração & dosagem , Celulose/análogos & derivados , Celulose/química , Inibidores de Ciclo-Oxigenase 2/administração & dosagem , Composição de Medicamentos , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Cinética , Membranas Artificiais , Modelos Químicos , Osmose , Permeabilidade , Plastificantes/química , Polietilenoglicóis/química , Solubilidade , ComprimidosRESUMO
Rigid polyurethane foams were synthesized using a renewable polyol from the simple physical mixture of castor oil and crude glycerol. The effect of the catalyst (DBTDL) content and blowing agents in the foams' properties were evaluated. The use of physical blowing agents (cyclopentane and n-pentane) allowed foams with smaller cells to be obtained in comparison with the foams produced with a chemical blowing agent (water). The increase of the water content caused a decrease in density, thermal conductivity, compressive strength, and Young's modulus, which indicates that the increment of CO2 production contributes to the formation of larger cells. Higher amounts of catalyst in the foam formulations caused a slight density decrease and a small increase of thermal conductivity, compressive strength, and Young's modulus values. These green foams presented properties that indicate a great potential to be used as thermal insulation: density (23-41 kg·m-3), thermal conductivity (0.0128-0.0207 W·m-1·K-1), compressive strength (45-188 kPa), and Young's modulus (3-28 kPa). These biofoams are also environmentally friendly polymers and can aggregate revenue to the biodiesel industry, contributing to a reduction in fuel prices.
Assuntos
Óleo de Rícino/química , Glicerol/química , Poliuretanos/química , Catálise , Misturas Complexas/química , Módulo de Elasticidade , Condutividade TérmicaRESUMO
The objective of this study was to develop a clear aqueous mixed nanomicellar formulation (NMF) of triamcinolone acetonide (TA) with a combination of nonionic surfactant hydrogenated castor oil 60 (HCO-60) and octoxynol-40 (Oc-40). In order to delineate the effects of drug-polymer interactions on entrapment efficiency (EE), loading efficiency (LE), and critical micellar concentration (CMC), a design of experiment (DOE) was performed to optimize the formulation. In this study, full-factorial design has been used with HCO-60 and OC-40 as independent variables. All formulations were prepared following solvent evaporation and film rehydration method, characterized with size, polydispersity, shape, morphology, EE, LE, and CMC. A specific blend of HCO-60 and Oc-40 at a particular wt% ratio (5:1.5) produced highest drug EE, LE, and smallest CMC (0.0216 wt%). Solubility of TA in NMF improved 20 times relative to normal aqueous solubility. Qualitative 1H NMR studies confirmed the absence of free drug in the outer aqueous NMF medium. Moreover, TA-loaded NMF appeared to be highly stable and well tolerated on human corneal epithelial cells (HCEC) and human retinal pigment epithelial cells (D407 cells). Overall, these studies suggest that TA in NMF is safe and suitable for human topical ocular drop application.
Assuntos
Triancinolona Acetonida/administração & dosagem , Administração Tópica , Animais , Óleo de Rícino/química , Córnea/citologia , Células Epiteliais/efeitos dos fármacos , Humanos , Micelas , Octoxinol/química , Soluções Oftálmicas , Epitélio Pigmentado da Retina/efeitos dos fármacos , Solubilidade , Tensoativos/química , Triancinolona Acetonida/toxicidade , Água/químicaRESUMO
This work investigates the effects of electroporation parameters on the transdermal delivery of insulin. Electroporation (EP) is known to induce temporal pores in the membrane, which are expected to enhance the diffusion of insulin through rabbits' skin. For such purpose, 5 different formulations of insulin and enhancers are applied to rabbit groups (5 rabbits each) with induced hyperglycemia in the presence of electroporative pulses. The blood sugar level (BSL) is followed up to 5-hour duration starting from the administration of the hyperglycemia-inducing factor. The effect of different electroporation parameters on BSL of rabbits is examined and compared with control groups. Results show that the increase in the number of pulses (from 15 up to 60 successive pulses) at an insulin concentration of 50 IU/mL, the increase in insulin concentration (from 50 to 70 IU/mL), and the decrease in applied field strength (from 200 to 100 V/cm) result in a significant decrease in BSL compared with control. Among all of the investigated formulations, the best performance is recorded for the insulin solution + EP (without enhancers) in almost all of the studied experimental conditions.
Assuntos
Eletroporação/métodos , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Resinas Acrílicas/química , Administração Cutânea , Animais , Glicemia/efeitos dos fármacos , Óleo de Rícino/química , Sistemas de Liberação de Medicamentos , Feminino , Concentração de Íons de Hidrogênio , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Iodo/química , Ácido Oleico/química , CoelhosRESUMO
Resistance to conventional synthetic pesticides has been widely reported in Dermanyssus gallinae in different aviary systems. Cardboard traps containing acaricides had been introduced as a successive device for collection and control of the poultry red mite. The present study assessed field efficacy of traps containing carvacrol in the control and reduction of D. gallinae in laying poultry farm. Two different carvacrol-based formulations were tested for their toxicity and possible repellent activity on D. gallinae to determine the most appropriate formulation and concentration to be used in the field study. In vitro tests confirmed that 1 % carvacrol formulation with ethoxylated castor oil as emulsifier was significantly toxic to D. gallinae without any dissuading effect in comparison to ethanol and higher concentrations of carvacrol (p < 0.05). A subsequent in vivo experiment in a cage system laying farm demonstrated significant acaricidal activity for traps containing 1 % carvacrol. Throughout the study, untreated cardboard traps were used for monitoring mite populations. Carvacrol-impregnated traps were efficacious in the control of D. gallinae and led to over 92 % reduction in mite's population after 2 week of application. Toxic effects of carvacrol maintained through 2 weeks after the last application of traps. Results of the present study suggested that effective control of the poultry red mite can be achieved by traps containing carvacrol. These traps can be used safely in poultry facilities without any concern about residues in eggs, meat, and environment.
Assuntos
Infestações por Ácaros/tratamento farmacológico , Infestações por Ácaros/veterinária , Ácaros/efeitos dos fármacos , Monoterpenos/farmacologia , Controle de Pragas/métodos , Acaricidas/farmacologia , Animais , Óleo de Rícino/química , Cimenos , Resistência a Medicamentos , Aves Domésticas , Doenças das Aves Domésticas/prevenção & controleRESUMO
The flavonoid quercetin (QU) is a naturally occurring compound with several biological activities. However, the oral bioavailability of this compound is very low due to the high pre-systemic metabolism in the colon and liver and its low water solubility. In this context, the development of QU-loaded nanocarriers (NEs) is a promising approach to improve the drug oral bioavailability. This study investigates the variation of the concentration of 12-hydroxystearic acid-polyethylene glycol copolymer, lecithin and castor oil (CO) as to increase the amount of QU encapsulated while maintaining physicochemical characteristics described in previous studies. To better understand the ability to load and release the drug, we investigated the molecular interactions between QU and NE. Lipid-based NEs were prepared using CO as oily phase and PEG 660-stearate and lecithin as surfactants. Hot solvent diffusion and phase inversion temperature were methods employed to produce NEs. The QU-NEs were investigated for physicochemical characteristics and in vitro drug release. Molecular interactions between QU and the NEs were monitored through the complementary infrared (Fourier transform infrared) and NMR. The results revealed that it was possible to incorporate higher amounts of QU in a lipid-based NE with a reduced size (20 nm). The system developed allow a sustained release of QU probably due to the shell formed by the surfactants around the NE and the flavonoid ordering effect in the emulsion hydrophobic regions, which may reduce the system permeability.
Assuntos
Óleo de Rícino/química , Portadores de Fármacos/química , Lecitinas/química , Nanopartículas/química , Polietilenoglicóis/química , Quercetina/administração & dosagem , Ácidos Esteáricos/química , Composição de Medicamentos , Interações Medicamentosas , Liberação Controlada de Fármacos , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Quercetina/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de SuperfícieRESUMO
In this paper, we present novel microemulsion (ME)-based semisolid polymer gels designed for topical administration of poorly water soluble non-steroidal anti-inflammatory drugs. Indomethacin (IND) was used as a model compound. The ME consisted of castor oil, water, Tween®80 as a surfactant and ethanol as cosurfactant. To obtain the desired consistency of the formulations Carbopol®960 was applied as a thickening agent. The aim of the study was to analyze in detail the mechanical properties of the obtained systems, with special attention paid to the features crucial for topical application. The rheological and textural experiments performed for samples with and without the incorporated drug clearly indicate that flow characteristics, viscoelastic properties and texture profiles were affected by the presence of IND. Novel semisolid formulations with IND described for the first time in this paper can be considered as an alternative for commercially available conventional topical dosage forms.
Assuntos
Emulsões/química , Géis/química , Indometacina/química , Polímeros/química , Administração Tópica , Anti-Inflamatórios não Esteroides/química , Óleo de Rícino/química , Química Farmacêutica/métodos , Etanol/química , Excipientes/química , Polissorbatos/química , Reologia , Solubilidade , Tensoativos/química , Viscosidade , Água/químicaRESUMO
CONTEXT: Levosulpiride (LSP) is a hydrophobic benzamide derivative used in the treatment of schizophrenia. SNEDDS were extensively practiced for systemic delivery of poorly aqueous soluble drugs to achieve maximum bioavailability. OBJECTIVE: The present study was focussed on the formulation, optimisation and evaluation of LSP SNEDDS using castor oil, for enhancement of drug absorption and bioavailability. MATERIALS AND METHODS: Pseudo-ternary phase diagram was plotted to identify the range of SNEDDS components. Twenty formulations were designed, prepared and characterised by its particle size, zeta potential, viscosity, and stability. In vitro dissolution data modelling was performed. Microscopy, FTIR and in vivo bioavailability studies were conducted for optimum formulation. Results, discussion and conclusion: F18 containing castor oil, 0.9 mL; PEG 600, 1.36 mL and Tween 80, 2.74 mL was found to be optimum. The optimised formulation had shown uniform globule size, no interactions of LSP with SNEDDS components and higher pharmacokinetic parameters than that of commercial preparation.