Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 84.904
Filtrar
1.
Acta Crystallogr C Struct Chem ; 75(Pt 9): 1250-1258, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31484813

RESUMO

A drug-drug anhydrous pharmaceutical salt containing tolbutamide {systematic name: 3-butyl-1-[(4-methylbenzene)sulfonyl]urea, TOL, C12H18N2O3S} and metformin (systematic name: 1-carbamimidamido-N,N-dimethylmethanimidamide, MET, C4H11N5) was created based on antidiabetic drug combinations to overcome the poor pharmaceutical properties of the parent drugs. Proton transfer and the proportion of the two components were confirmed by 1H NMR spectroscopy and single-crystal X-ray diffraction analysis. Comprehensive characterization of the new pharmaceutical salt crystal, 2-[(dimethylamino)(iminiumyl)methyl]guanidine (butylcarbamoyl)[(4-methylbenzene)sulfonyl]azanide, C4H12N5+·C12H17N2O3S-, was performed and showed enhancement of the pharmaceutical properties, such as lower hygroscopicity and greater accelerated stability than the parent drug MET, and higher solubility and dissolution rate than TOL. The property alterations were correlated with the crystal packing features and potential hydrogen-bonding sites through observed changes in the crystal structures.


Assuntos
Hipoglicemiantes/farmacologia , Metformina/farmacologia , Tolbutamida/farmacologia , Cristalografia por Raios X , Combinação de Medicamentos , Ligações de Hidrogênio , Hipoglicemiantes/síntese química , Hipoglicemiantes/química , Metformina/síntese química , Metformina/química , Estrutura Molecular , Solubilidade , Tolbutamida/síntese química , Tolbutamida/química
2.
J Agric Food Chem ; 67(37): 10361-10372, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31487173

RESUMO

Alkyl di-/tri-/tetraoxyethyl ß-d-xylopyranosides as derivatives of alkyl xylosides are a class of non-ionic sugar-based surfactants. They were stereoselectively synthesized by the Helferich method. Their properties including hydrophilic-lipophilic balance number, water solubility, surface property, foam property, emulsifying property, and thermotropic liquid crystal property were mainly investigated. The results showed that their water solubility decreased with increasing the alkyl chain length and increasing the number of the oligooxyethyl fragment. The critical micelle concentration had a monotonous decreasing trend with increasing the alkyl chain length. Nonyl di-/tri-/tetraoxyethyl ß-d-xylopyranosides [-(OCH2CH2)m-, where m = 2, 3, and 4] exhibited the most excellent foaming ability and foam stability. In the n-octane/water system, dodecyl tetraoxyethyl ß-d-xylopyranosides and tetradecyl tetraoxyethyl ß-d-xylopyranosides had the strongest emulsion ability. In addition, some alkyl di-/tri-/tetraoxyethyl ß-d-xylopyranosides had thermotropic liquid crystal properties. Such sugar-based surfactants, alkyl di-/tri-/tetraoxyethyl ß-d-xylopyranosides, will be expected to develop for a variety of practical application.


Assuntos
Glicosídeos/química , Tensoativos/química , Glicosídeos/síntese química , Interações Hidrofóbicas e Hidrofílicas , Solubilidade , Propriedades de Superfície , Tensoativos/síntese química
3.
J Agric Food Chem ; 67(38): 10587-10594, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31497957

RESUMO

Inefficient usage and overdosage of conventional pesticide formulations has resulted in large economic losses and environmental pollution due to their poor water solubility and weak adhesion to foliage. In order to develop a green and efficient pesticide formulation, a kind of alkyd resin (AR) based on vegetable oil was first synthesized and used to fabricate the lambda-cyhalothrin/AR (LC/AR) nanoemulsion via in situ phase inverse emulsification, and its properties were then investigated. Results showed that the particle size of the LC/AR nanoemulsion was 50-150 nm with maximum LC loading capacity of as much as 40.9 wt %, high encapsulation efficiency >90%, and great stability in multiple environments. The LC/AR nanoemulsion exhibited better controlled release characteristics compared with LC commercial formulations, and a stronger adhesion on the foliage of the resulted nanoemulsion was also observed, which was attributed to low surface tension and strong interactions with foliar surfaces.


Assuntos
Preparações de Ação Retardada/química , Composição de Medicamentos/métodos , Nitrilos/química , Praguicidas/química , Piretrinas/química , Emulsões/química , Tamanho da Partícula , Solubilidade
4.
J Appl Oral Sci ; 27: e20180262, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31508789

RESUMO

The incorporation of antimicrobials in the composites as an attempt to reduce bacterial adhesion without jeopardizing mechanical properties is a challenge for Dentistry. OBJECTIVE To evaluate the bacterial adhesion and physical properties of a composite containing the methacrylate triclosan- derivative monomer (TM). METHODOLOGY TM was synthesized and added to an experimental composite. Samples were divided into two groups: Control and TM (13.4 wt%). Antibacterial Activity: Three specimens of each material were prepared and placed on bacterial suspensions of Streptococcus mutans for 1, 5 and 10 days. After these periods the counting of the colonies (log10) was performed. Assays was performed in triplicate. Physical Properties: Three-body Abrasion (TBA): Ten specimens of each material were prepared and stored at 37°C/24 h. The surface roughness (Ra) and hardness (KHN) were analyzed. Next, the specimens were submitted to abrasive wear (30,000 cycles) and re-evaluated for Ra and KHN; Sorption/solubility (SS): cylindrical specimens (n=10) were prepared and weighted. The specimens were immersed in deionized water for 7 days at 37°C and then their weight was verified again. SS were calculated using accepted formulas; Diametral tensile strength (DTS): specimens (n=10) underwent test performed in an Instron universal testing machine at a crosshead speed of 1 mm/min. Data were submitted to appropriate statistical tests according to data distribution and assay (p<0.05). RESULTS Bacterial Adhesion: TM showed a significant reduction on biofilm accumulation in the evaluated periods: 1 day (1.537±0.146); 5 days (2.183±0.138) and 10 days (4.469±0.155) when compared with Control: 1 day (4.954±0.249); 5 days (5.498±0.257) and 10 days (6.306±0.287). Physical Properties: For TBA, SS and DTS no significant difference was found between groups Control and TM. The incorporation of methacrylate triclosan-based monomer in the experimental composite reduce bacterial adhesion of S. mutans and did not affect important polymer properties.


Assuntos
Antibacterianos/química , Resinas Compostas/química , Metacrilatos/química , Triclosan/química , Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Contagem de Colônia Microbiana , Resinas Compostas/farmacologia , Testes de Dureza , Teste de Materiais , Metacrilatos/farmacologia , Valores de Referência , Reprodutibilidade dos Testes , Solubilidade , Streptococcus mutans/efeitos dos fármacos , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo , Escovação Dentária , Triclosan/farmacologia
5.
J Appl Oral Sci ; 27: e20180556, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31508791

RESUMO

OBJECTIVE: To evaluate the effect of ultrasonic and sonic activation on physicochemical properties of AH Plus, MTA Fillapex, ADSeal, GuttaFlow Bioseal, and GuttaFlow 2 sealers. METHODOLOGY: Three experimental groups were formed: no activation (NA), ultrasonic activation (UA), and sonic activation (SA). The sealers were manipulated according to the manufacturers' instructions. A 3-mL syringe was adapted to receive 1 mL of sealer. Activation was performed with a 20/.01 ultrasonic insert (20 s/1W) in the UA group. A size 35.04 sonic tip was used (20 s/10,000 cycles/min-1) in the SA group. The molds for physicochemical analysis were filled and evaluated according to ANSI/ADA specification no. 57: setting time (ST), flow (FL), dimensional change (DC), solubility (SB), and radiopacity (RD). Statistical analysis was performed by Kruskal-Wallis, one-way ANOVA, and Tukey's tests (P<0.05). RESULTS: Regarding ST, only AH Plus and GuttaFlow 2 in the NA group met the ANSI/ADA standards. All FL values were greater than 20 mm in diameter, as determined by ANSI/ADA. The tested sealers and protocols did not comply with the ANSI/ADA standards for DC. As for SB, only MTA Fillapex, regardless of the activation protocol, did not follow the ANSI/ADA standards. All of the investigated sealers, regardless of the activation protocol, presented radiographic density higher than 3 mm Al, as proposed by ANSI/ADA. CONCLUSIONS: UA and SA promoted changes in the physicochemical properties of the evaluated root canal sealers, mainly in ST and F. Thus, it is important to evaluate the physicochemical properties of endodontic sealers associated with activation techniques prior to clinical application in order to determine whether the properties follow the parameters set by ANSI/ADA, ensuring safety and quality of root canal filling.


Assuntos
Compostos de Alumínio/química , Compostos de Cálcio/química , Dimetilpolisiloxanos/química , Resinas Epóxi/química , Guta-Percha/química , Óxidos/química , Materiais Restauradores do Canal Radicular/química , Silicatos/química , Ondas Ultrassônicas , Análise de Variância , Combinação de Medicamentos , Teste de Materiais , Valores de Referência , Reprodutibilidade dos Testes , Solubilidade , Estatísticas não Paramétricas , Propriedades de Superfície , Fatores de Tempo
6.
Ecotoxicol Environ Saf ; 182: 109443, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31398782

RESUMO

The continuous presence of toxic elements in the aquatic environments around mine tailings occurs due to bioleaching or chemical extraction promoted by the mining operations. Biogenic passivation treatment of tailings dams can be a new environment-friendly technique to inhibit the solubility of heavy metals. In spite of current bioleaching researches, we tried to minimize the mobility of the trace elements in the laboratory scale through the formation of a passivation layer in the presence of a mixed culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The X-ray diffraction (XRD) and scanning electron microscope (SEM) represented the jarosite generation as an inhibitory layer on the mineral surfaces of the tested materials. More detailed observations on electron probe micro-analyzer (EPMA) showed the co-precipitation of metals with the passivation layer. Thereby, the passivation layer demonstrates potential in elements immobilization which, in turn, can be optimized in the natural systems. Our working hypothesis was to exploit and optimize the formation of the passivation layer to maximize the immobilization of heavy metals (e.g., Cu, Cr). The optimization process of bioleaching experiments using indigenous bacteria caused a reduced solubility for Cu (from around 20% to 4.5%) and Cr (from around 30% to 10.6%) and the formation of 6.5 gr passivation layer. The analyses finally represented the high efficiency of the passivation technique to minimize metals bioleaching in comparison to earlier studies.


Assuntos
Metais Pesados/química , Mineração , Sulfetos/química , Poluentes Químicos da Água/química , Acidithiobacillus , Acidithiobacillus thiooxidans , Bactérias , Biodegradação Ambiental , Compostos Férricos , Metais Pesados/análise , Minerais , Solubilidade , Sulfatos , Sulfetos/análise , Poluentes Químicos da Água/análise
7.
World J Microbiol Biotechnol ; 35(8): 125, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363859

RESUMO

The global need to develop sustainable materials and products from non-fossil raw material is pushing industry to utilize side-streams more efficiently using green processes. Aromatic lignin, the world's second most abundant biopolymer, has multiple attractive properties which can be exploited in various ways instead of being burnt or used as animal feed. Lignin's poor water solubility and its highly branched and random structure make it a challenging biopolymer to exploit when developing novel technologies for the preparation of tailored nanobiomaterials for value-added applications. The notable number of scientific publications focusing on the formation and modification of technical lignin in nanoparticulate morphology show that these bottlenecks could be solved using lignin in the form of colloidal particles (CLPs). These particles are very stable at wide pH range (4-11) and easily dispersible in organic solvents after stabilized via cross-linking. Negative hydroxyl groups on the CLP surface enable multiple enzymatic and chemical modifications e.g. via polymerization reactions and surface-coating with positive polymers. This contribution highlights how tailored CLPs could be innovatively exploited in different the state-of-the-art applications such as medicine, foods, and cosmetics.


Assuntos
Química Verde/métodos , Lignina/síntese química , Lignina/metabolismo , Nanopartículas/química , Nanopartículas/metabolismo , Animais , Biotransformação , Solubilidade
8.
World J Microbiol Biotechnol ; 35(8): 126, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363938

RESUMO

Isolation and identification of temperature tolerant phosphate solubilizing bacteria (TTPSB) and their use as microbial fertilizers was the main goal of the study. In this study, TTPSB were isolated from soil samples treated for 16 h at 55 °C. Their phosphate solubilizing activity was either evaluated in solid media by forming a clear zone (halo) or in liquid media by quantification of the soluble phosphate in the growth medium. Five colonies (RPS4, RPS6, RPS7, RPS8 and RPS9) were identified to be able to form a halo and two of the isolates (RPS9 and RPS7) tolerated a temperature of 55 °C. With tricalcium phosphate (TCP) as the sole P-source, the phosphate solubilizing capacity of RPS9 and RPS7 was determined to be 563.8 and 324.1 mg P L-1 in liquid Sperber medium, respectively. Both bacterial isolates were identified as Pantoea agglomerans by molecular and biochemical characterization. To be used as a microbial fertilizer a carrier system for the temperature tolerant bacteria consisting of rock phosphate, sulfur and bagasse was used. It could be established that the bacterial cell counts of the microbial fertilizers were acceptable for application after storage for 4 months at 28 °C. In a greenhouse experiment using pot cultures, inoculation of maize (S.C.704) with the microbial fertilizers in an autoclaved soil resulted in a significant effect on total fresh and dry weight of the plant root and shoot as well as on the P content of the root and shoot. The effects observed with RPS9 as a component of the microbial fertilizer on plant growth and P nutrition was comparable with the addition of 50% of recommended triple superphosphate (TSP) dose. Using temperature tolerant bacteria in microbial fertilizers will overcome limitations in production and storage of the microbial fertilizers and contribute to a environmentally-friendly agriculture. The temperature tolerant P. agglomerans strain RPS9 was shown to be effective as part of a microbial fertilizer in supporting the growth and P uptake in maize.


Assuntos
Agricultura/métodos , Fosfatos de Cálcio/metabolismo , Pantoea/isolamento & purificação , Pantoea/metabolismo , Microbiologia do Solo , Zea mays/crescimento & desenvolvimento , Técnicas Bacteriológicas , Biotransformação , Fosfatos de Cálcio/química , Meios de Cultura/química , Temperatura Alta , Pantoea/classificação , Pantoea/efeitos da radiação , Solubilidade , Zea mays/microbiologia
9.
Ying Yong Sheng Tai Xue Bao ; 30(7): 2384-2392, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31418242

RESUMO

A phosphate solubilizing fungus was isolated from the rhizosphere of tomato in greenhouse in Liaozhong County, Liaoning Province, Northeast China. The strain was identified as a new strain of Penicillium oxalicum by morphological characteristics and ITS rDNA sequence comparison, and then was named PSF1. Strain PSF1 could utilize various carbon sources such as glucose, sucrose, lactose, galactose, soluble starch and nitrogen sources such as ammonium sulfate, ammonium chloride, ammonium nitrate, potassium nitrate, urea for growth and metabolism, with an efficient phosphate solubilizing capacity. It grew well and had a high ability of phosphate solubilization under the conditions of C/N 10:1-60:1 and initial pH 7-8. Strain PSF1 had strong acid production ability, with the pH of culture mediums decreasing from 7.00-7.50 to 2.06-4.87 during the culture process. The highest phosphate solubilizing capacity in four phosphorus sources mediums was tricalcium phosphate (869.62 mg·L-1) > phosphate rock power (233.56 mg·L-1) > aluminum phosphate (44.77 mg·L-1) > iron phosphate (28.42 mg·L-1). Results from Pearson correlation analysis showed that there were significant negative correlations between the changes of phosphate solubili-zing capacity and pH in tricalcium phosphate, phosphate rock power and iron phosphate mediums, but no significant correlation in aluminum phosphate medium. Strain PSF1 had strong phosphate solu-bilizing capacity and wide growing conditions, thus would have strong phosphate solubilizing capacity in soil.


Assuntos
Fungos/metabolismo , Fosfatos/metabolismo , Microbiologia do Solo , China , Rizosfera , Solubilidade
10.
Braz Oral Res ; 33: e075, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31432926

RESUMO

Resinous infiltrants are indicated in the treatment of incipient carious lesions, and further development of these materials may contribute to greater control of these lesions. The aim of this study was to analyze the physical and antibacterial properties of experimental infiltrants containing iodonium salt and chitosan. Nine experimental infiltrants were formulated by varying the concentration of the diphenyliodonium salt (DPI) at 0, 0.5 and 1 mol%; and chitosan at 0, 0.12 and 0.25 g%. The infiltrants contained the monomeric base of triethylene glycol dimethacrylate and bisphenol-A dimethacrylate ethoxylate in a 75 and 25% proportion by weight, respectively; 0.5 mol% camphorquinone and 1 mol% ethyl 4-dimethylaminobenzoate. The degree of conversion was evaluated using Fourier transformer infrared spectroscopy, and the flexural strength and elastic modulus using the three-point bending test. Sorption and solubility in water, and antibacterial analysis (minimum inhibitory concentration and minimum bactericidal concentration) were also analyzed. Data was analyzed statistically by two-way ANOVA and Tukey's test (p<0.05), with the exception of the antibacterial test, which was evaluated by visual inspection. In general, the infiltrant group containing 0.5% DPI and 0.12% chitosan showed high values of degree of conversion, higher values of elastic modulus and flexural strength, and lower sorption values in relation to the other groups. Antibacterial activity was observed in all the groups with DPI, regardless of the concentration of chitosan. The addition of DPI and chitosan to experimental infiltrants represents a valid option for producing infiltrants with desirable physical and antibacterial characteristics.


Assuntos
Antibacterianos/química , Quitosana/química , Resinas Compostas/química , Metacrilatos/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Sais/química , Análise de Variância , Antibacterianos/farmacologia , Quitosana/farmacologia , Resinas Compostas/farmacologia , Módulo de Elasticidade , Resistência à Flexão , Lactobacillus acidophilus/efeitos dos fármacos , Cura Luminosa de Adesivos Dentários , Teste de Materiais , Metacrilatos/farmacologia , Testes de Sensibilidade Microbiana , Polietilenoglicóis/farmacologia , Ácidos Polimetacrílicos/farmacologia , Valores de Referência , Reprodutibilidade dos Testes , Sais/farmacologia , Solubilidade , Estatísticas não Paramétricas , Streptococcus mutans/efeitos dos fármacos
11.
Chem Pharm Bull (Tokyo) ; 67(8): 816-823, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31366831

RESUMO

In this present study a new co-crystals of zoledronic acid with DL-tartaric acid and nicotinamide has been developed with improved solubility. Zoledronic acid is a class III drug with poor oral bioavailability due to its poor permeability and low aqueous solubility; hence an attempt has been made to improve its solubility by co-crystallization technology. Pharmaceutical cocrystals are multi-component crystals with a stoichiometric ratio of active pharmaceutical ingredients (APIs) and cocrystal coformers (CCFs) that are assembled by noncovalent interactions such as hydrogen bonds, π-π packing, and Vander Waals forces. In this study the coformers selected were DL-tartaric acid and nicotinamide based on ease of hydrogen bond formation. The co-crystal of zoledronic acid with DL-tartaric acid were prepared in three ratios (1 : 1, 1 : 2 and 2 : 1) by slow solvent evaporation method and with nicotinamide in 1 : 1 ratio by dry grinding method. The formation of co-crystal was confirmed by powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC) and Fourier transform (FT)IR. The dynamic solubility of co-crystals with DL-tartaric acid in the ratios 1 : 1, 1 : 2 and 2 : 1 increased by fold as compared to pure drug.


Assuntos
Desenho de Drogas , Niacinamida/química , Tartaratos/química , Ácido Zoledrônico/química , Varredura Diferencial de Calorimetria , Cristalização , Estrutura Molecular , Difração de Pó , Solubilidade , Ácido Zoledrônico/síntese química
12.
Pharm Res ; 36(10): 142, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31376020

RESUMO

BACKGROUND: With the recent approval of the first small interfering RNA (siRNA) therapeutic formulated as nanoparticles, there is increased incentive for establishing the factors of importance for the design of stable solid dosage forms of such complex nanomedicines. METHODS: The aims of this study were: (i) to identify factors of importance for the design of spray-dried siRNA-loaded lipidoid-poly(DL-lactic-co-glycolic acid) hybrid nanoparticles (LPNs), and (ii) to evaluate their influence on the resulting powders by using a quality-by-design approach. Critical formulation and process parameters were linked to critical quality attributes (CQAs) using design of experiments, and an optimal operating space (OOS) was identified. RESULTS: A series of CQAs were identified based on the quality target product profile. The loading (ratio of LPNs to the total solid content) and the feedstock concentration were determined as critical parameters, which were optimized systematically. Mannitol was chosen as stabilizing excipient due to the low water content of the resulting powders. The loading negatively affected the colloidal stability of the LPNs, whereas feedstock concentration correlated positively with the powder particle size. The optimal mannitol-based solid formulation, defined from the OOS, displayed a loading of 5% (w/w), mass median aerodynamic diameter of 3.3 ± 0.2 µm, yield of 60.6 ± 6.6%, and a size ratio of 1.15 ± 0.03. Dispersed micro-embedded LPNs had preserved physicochemical characteristics as well as in vitro siRNA release profile and gene silencing, as compared to non-spray-dried LPNs. CONCLUSION: The optimal solid dosage forms represent robust formulations suitable for higher scale-up manufacturing.


Assuntos
Dessecação/métodos , Lipídeos/química , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , RNA Interferente Pequeno/química , Administração por Inalação , Animais , Composição de Medicamentos , Excipientes/química , Inativação Gênica , Técnicas de Transferência de Genes , Manitol/química , Camundongos , Nanomedicina , Tamanho da Partícula , Pós , Células RAW 264.7 , RNA Interferente Pequeno/administração & dosagem , Solubilidade , Solventes/química
13.
Expert Opin Ther Pat ; 29(9): 703-731, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31369715

RESUMO

Introduction: Combretastatins represent a potent class of phenolic-stilbene natural products that function as colchicine binding site inhibitors of tubulin polymerization and have been advanced as promising anticancer lead compounds. Among them, combretastatin A-4 is the most potent lead molecule due to its broad spectrum cytotoxicity against a variety of tumors. However, low water solubility due to its high lipophilic nature and inter-conversion of olefinic double bond from more active cis to less active trans-conformation poses limitations to its clinical utility. However, different approaches including prodrugs, salt formations, structural modifications, prevention of inter-conversion of the olefinic bond and changes to the substitution pattern on the rings of combretastatin A-4 were investigated and successfully resulted in different combretastatin-based molecules that demonstrated varying levels of potency against different types of tumors during their in-vitro and in-vivo studies. Areas covered: This review covers the patents over a period of 2008-2018. Expert opinion: Molecular hybridization and prodrug designing imparted multi-targeted actions to combretastatin derivatives. Currently, various combretastatin derivatives are under clinical trials. These derivatives could be used to treat disorders other than cancer, due to their vascular disrupting action.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Bibenzilas/farmacologia , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos Fitogênicos/química , Bibenzilas/química , Desenho de Drogas , Humanos , Patentes como Assunto , Solubilidade , Relação Estrutura-Atividade , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia
14.
Int J Nanomedicine ; 14: 5435-5448, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31409997

RESUMO

Background: Ramipril (RMP) suffers from poor aqueous solubility along with sensitivity to mechanical stress, heat, and moisture. The aim of the current study is to improve RMP solubility and stability by designing solid self-nanoemulsifying drug delivery system (S-SNEDDS) as tablet. Methods: The drug was initially incorporated in different liquid formulations (L-SNEDDS) which were evaluated by equilibrium solubility, droplet size, and zeta potential studies. The optimized formulation was solidified into S-SNEDDS powder by the adsorbent Syloid® and compressed into a self-nanoemulsifying tablet (T-SNEDDS). The optimized tablet was evaluated by drug content uniformity, hardness, friability, disintegration, and dissolution tests. Furthermore, pure RMP, optimized L-SNEDDS, and T-SNEDDS were enrolled in accelerated and long-term stability studies. Results: Among various liquid formulations, F5 L-SNEDDS [capmul MCM/transcutol/HCO-30 (25/25/50%w/w)] showed relatively high drug solubility, nano-scaled droplet size, and high negative zeta potential value. The optimized SNEDDS solidification with Syloid® at ratio (1:1) resulted in a compressible powder with an excellent flowability. The optimized tablet (T-SNEDDS) showed accepted content uniformity, hardness, friability, and disintegration time (<15 minutes). The optimized L-SNEDDS, S-SNEDDS, and T-SNEDDS showed superior enhancement of RMP dissolution compared to the pure drug. Most importantly, T-SNEDDS showed significant (P<0.05) improvement of RMP stability compared to the pure drug and L-SNEDDS in both accelerated and long-term stability studies. Conclusion: RMP-loaded T-SNEDDS offers a potential oral dosage form that provides combined improvement of RMP dissolution and chemical stability.


Assuntos
Sistemas de Liberação de Medicamentos , Emulsões/química , Nanopartículas/química , Ramipril/farmacologia , Administração Oral , Adsorção , Disponibilidade Biológica , Varredura Diferencial de Calorimetria , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Dureza , Nanopartículas/ultraestrutura , Tamanho da Partícula , Controle de Qualidade , Solubilidade , Eletricidade Estática , Comprimidos/química , Fatores de Tempo , Difração de Raios X
15.
Polim Med ; 49(1): 5-18, 2019.
Artigo em Polonês | MEDLINE | ID: mdl-31464108

RESUMO

BACKGROUND: Hydrophilic matrices used as oral forms of sustained release drugs are a suitable application medium for short-acting nonsteroidal anti-inflammatory drugs (NSAID) - ketoprofen. A properly selected hydrophilic matrix in oral preparations may significantly increase efficacy and application safety of ketoprofen. OBJECTIVES: The aim of the research was to analyze the usefulness of polymers (synthetic Kollidon K25 and K90, semi-synthetic hydroxyethylcellulose) and calcium hydrogen phosphate dihydrate (as an inorganic filler) in manufacturing solid oral matrix forms of ketoprofen and to study of the effect of non-ionic surfactants (Tween 80, Rofam 70) on release kinetics. MATERIAL AND METHODS: Ketoprofen, HEC, Kollidon K25, and K90, calcium hydrogen phosphate, magnesium stearate. Incorporation. Studies on the tablet mass. Direct tableting. Studies on the pharmacopoeial parameters and pharmaceutical availability. Approximation of the results. RESULTS: The results of the granulometric studies on tablet mass were in accordance with pharmacopoeial standards. The results of morphological and biopharmaceutical studies of the obtained matrices (tablets) were consistent with the pharmacopoeial standards for formulations with HEC, K25 and K90. The release results most closely related to row 0 kinetics were obtained for the matrix containing HEC and K25. Tween 80 added to 0.1N HCl accelerated the release of ketoprofen, while Rofam 70 decelerated it. Tween 80 and Rofam 70 added to the pH 7.4 buffer accelerated the release of ketoprofen. CONCLUSIONS: The presented model system of preformulation studies showed the usefulness of HEC and Kolidon K25 in the technology of hydrophilic matrices with ketoprofen. Surfactants added to the medium do not affect the release rate of ketoprofen.


Assuntos
Anti-Inflamatórios não Esteroides , Portadores de Fármacos , Cetoprofeno , Polímeros , Anti-Inflamatórios não Esteroides/administração & dosagem , Preparações de Ação Retardada , Cetoprofeno/administração & dosagem , Cinética , Polissorbatos , Povidona , Solubilidade , Tensoativos , Comprimidos
16.
Chem Commun (Camb) ; 55(67): 10015-10018, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31378791

RESUMO

We report the first neutral and water-soluble polymer capable of strong mitochondrial targeting in vitro and in vivo, zwitterionic poly[2-(N-oxide-N,N-diethylamino)ethyl methacrylate] (OPDEA). OPDEA is quickly internalized via macropinocytosis by various cancer cells and transferred into the mitochondria, which slightly lowers the mitochondrial membrane potential as determined by the JC-1 assay.


Assuntos
Mitocôndrias/metabolismo , Ácidos Polimetacrílicos/química , Animais , Linhagem Celular Tumoral , Corantes Fluorescentes/química , Humanos , Concentração de Íons de Hidrogênio , Potencial da Membrana Mitocondrial , Camundongos , Imagem Óptica/métodos , Permeabilidade , Ácidos Polimetacrílicos/metabolismo , Solubilidade , Água
17.
J Chromatogr A ; 1602: 135-141, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31255246

RESUMO

In this study, we investigated the potential of mixtures of tetrahydrofuran (THF) and water as tunable solvents for the microextraction of contaminants in solid and in liquid matrices. These two miscible solvents have very different dielectric constant and Hildebrand solubility parameters, so that tunable mixtures spanning a wide range of dispersion and hydrogen bonding forces could be easily prepared by simply changing their composition. In this way, rapid and more efficient extraction methods can be developed. A liquid-liquid and a solid-liquid microextraction method for the determination of bisphenol A (BPA) in urine and ochratoxin A (OTA) in cereal baby food were developed as a proof of concept. Both, the chemical composition and the relative solvency of the THF-water mixtures, expressed as Teas solubility parameters, were studied in order to gain some insights into the chemical interactions governing analyte extraction. For urine, the salting-out extraction with THF:water and NaCl was evaluated, a process which is still scarcely investigated for analytical purposes. These methods featured good recoveries (above 95%), satisfactory standard deviation (5-6%) and good sensitivity (detection limits of 0.l µg L-1 for BPA and of 0.l ng g-1 for OTA) with the advantages of simplicity, rapidity and low consumption of reagents. Recoveries for other compounds and matrices (bisphenols ad phosphorus flame retardants in dust and in tap water, dyes in tap water and OTA in powder milk) were also assessed to prove the wide potential of these tunable solvent mixtures.


Assuntos
Furanos/química , Solventes/química , Poluentes Químicos da Água/isolamento & purificação , Água/química , Compostos Benzidrílicos/urina , Criança , Feminino , Humanos , Alimentos Infantis/análise , Limite de Detecção , Microextração em Fase Líquida , Ocratoxinas/isolamento & purificação , Transição de Fase , Fenóis/urina , Solubilidade
18.
Food Chem ; 300: 125194, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31325749

RESUMO

The effects of near freezing temperature (NFT) storage at -1.9 °C on cell wall degradation of 'Shushanggan' apricot was studied comparing to 0 °C and 5 °C storage. Our results indicated that NFT storage strongly inhibited the solubilization of Na2CO3-soluble pectin and cellulose, by the suppression of cell wall modifying enzymes (polygalacturonase, ß-Galactosidase, pectin methyl esterase and cellulase) and related genes expressions. The loss of side chains was the main modification in CDTA (Cyclohexane-diamine-tetraacetic Acid)-soluble pectin during storage and made the main contribution to the softening of apricot, while the loss of side chain was suppressed by NFT storage. Microscopic observation showed that NFT storage delayed the degradation of pectin fraction and protected cell wall structure from loosing. This study proves that NFT storage is an effective technology to suppress the cell wall polysaccharides degradation and ultrastructure modification of apricot.


Assuntos
Parede Celular/ultraestrutura , Armazenamento de Alimentos/métodos , Polissacarídeos/química , Prunus armeniaca/química , Hidrolases de Éster Carboxílico/química , Hidrolases de Éster Carboxílico/metabolismo , Parede Celular/química , Parede Celular/metabolismo , Celulose/química , Temperatura Baixa , Congelamento , Frutas/química , Frutas/citologia , Frutas/ultraestrutura , Pectinas/química , Células Vegetais/química , Células Vegetais/ultraestrutura , Poligalacturonase/química , Poligalacturonase/metabolismo , Polissacarídeos/metabolismo , Prunus armeniaca/citologia , Solubilidade , beta-Galactosidase/química , beta-Galactosidase/metabolismo
19.
Biomater Sci ; 7(9): 3609-3613, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31361290

RESUMO

Development of versatile phototheranostics is highly desirable for cancer theranostics. Herein, a novel organic conjugated polymer (named DPP-TT) with excellent optical properties was designed and prepared. Based on single-component DPP-TT, single DPP-TT NPs as versatile phototheranostics were developed by a simple nanoprecipitation method. The obtained NPs exhibited good water solubility, excellent biocompatibility, outstanding photostability, strong NIR-I light absorption, and appropriate NIR-II fluorescence emission. Importantly, such NPs presented high photothermal conversion efficiency. From the investigations performed in vitro and in vivo, it was observed that DPP-TT NPs show remarkable performance for cancer theranostics, benefiting from single 808 nm laser-induced tri-modal (NIR-II fluorescence/photoacoustic/thermal) imaging-guided photothermal therapy.


Assuntos
Nanopartículas/química , Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Fototerapia/métodos , Animais , Materiais Biocompatíveis/química , Células HeLa , Humanos , Hipertermia Induzida , Camundongos , Imagem Multimodal/métodos , Imagem Óptica/métodos , Técnicas Fotoacústicas/métodos , Polímeros/química , Solubilidade , Nanomedicina Teranóstica
20.
Pharm Res ; 36(9): 131, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31263962

RESUMO

PURPOSE: Intranasal administration has been extensively applied to deliver drugs to the brain. In spite of its unfavorable biopharmaceutic properties, melatonin (MLT) has demonstrated anticancer effects against glioblastoma. This study describes the nose-to-brain delivery of MLT-loaded polycaprolactone nanoparticles (MLT-NP) for the treatment of glioblastoma. METHODS: MLT-NP were prepared by nanoprecipitation. Following intranasal administration in rats, brain targeting of the formulation was demonstrated by fluorescence tomography. Brain and plasma pharmacokinetic profiles were analyzed. Cytotoxicity against U87MG glioblastoma cells and MRC-5 non-tumor cells was evaluated. RESULTS: MLT-NP increased the drug apparent water solubility ~35 fold. The formulation demonstrated strong activity against U87MG cells, resulting in IC50 ~2500 fold lower than that of the free drug. No cytotoxic effect was observed against non-tumor cells. Fluorescence tomography images evidenced the direct translocation of nanoparticles from nasal cavity to the brain. Intranasal administration of MLT-NP resulted in higher AUCbrain and drug targeting index compared to the free drug by either intranasal or oral route. CONCLUSIONS: Nanoencapsulation of MLT was crucial for the selective antitumoral activity against U87MG. In vivo evaluation confirmed nose-to-brain delivery of MLT mediated by nanoparticles, highlighting the formulation as a suitable approach to improve glioblastoma therapy.


Assuntos
Antineoplásicos/farmacocinética , Encéfalo/metabolismo , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Melatonina/farmacocinética , Nanopartículas/química , Poliésteres/química , Administração Intranasal , Administração Oral , Animais , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Humanos , Concentração Inibidora 50 , Masculino , Melatonina/administração & dosagem , Ratos Wistar , Solubilidade , Distribuição Tecidual
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA