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1.
Pharm Res ; 38(6): 1081-1092, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34002324

RESUMO

PURPOSE: The aim of this work was to formulate and characterize surfactant-free glibenclamide nanoparticles using Eudragit RLPO and polyethylene glycol as sole stabilizer. METHODS: Glibenclamide nanoparticles were obtained by nanoprecipitation and evaluated in terms of drug content, encapsulation efficiency, apparent saturation solubility, drug release profile, solid state and storage stability. The influence of different stirring speed on the particle size, size distribution and zeta potential of the nanoparticles was investigated. The nanoparticle biocompatibility and permeability were analyzed in vitro on Caco-2 cell line (clone HTB-37) and its interaction with mucin was also investigated. RESULTS: It was found that increasing the molecular weight of polyethylene glycol from 400 to 6000 decreased drug encapsulation, whereas the aqueous solubility and dissolution rate of the drug increased. Particle size of the nanoformulations, with and without polyethylene glycol, were between 140 and 460 nm. Stability studies confirmed that glibenclamide nanoparticles were stable, in terms of particle size, after 120 days at 4°C. In vitro studies indicated minimal interactions of glibenclamide nanoparticles and mucin glycoproteins suggesting favorable properties to address the intestinal mucus barrier. Cell viability studies confirmed the safety profile of these nanoparticles and showed an increased permeation through epithelial cells. CONCLUSION: Taking into consideration these findings, polyethylene glycol is a useful polymer for stabilizing these surfactant-free glibenclamide nanoparticles and represent a promising alternative to improve the treatment of non-insulin dependent diabetes.


Assuntos
Composição de Medicamentos/métodos , Glibureto/metabolismo , Hipoglicemiantes/metabolismo , Mucosa Intestinal/metabolismo , Nanopartículas/metabolismo , Tensoativos , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Avaliação Pré-Clínica de Medicamentos/métodos , Glibureto/administração & dosagem , Glibureto/química , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/química , Mucosa Intestinal/efeitos dos fármacos , Nanopartículas/administração & dosagem , Nanopartículas/química , Tamanho da Partícula , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/química , Polietilenoglicóis/metabolismo , Polímeros/administração & dosagem , Polímeros/química , Polímeros/metabolismo
2.
Parasitology ; 148(5): 566-575, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33298212

RESUMO

Chagas disease is a serious parasitic infection caused by Trypanosoma cruzi. Unfortunately, the current chemotherapeutic tools are not enough to combat the infection. The aim of this study was to evaluate the trypanocidal activity of benznidazole-loaded microparticles during the acute phase of Chagas infection in an experimental murine model. Microparticles were prepared by spray-drying using copolymers derived from esters of acrylic and methacrylic acids as carriers. Dissolution efficiency of the formulations was up to 3.80-fold greater than that of raw benznidazole. Stability assay showed no significant difference (P > 0.05) in the loading capacity of microparticles for 3 years. Cell cultures showed no visible morphological changes or destabilization of the cell membrane nor haemolysis was observed in defibrinated human blood after microparticles treatment. Mice with acute lethal infection survived 100% after 30 days of treatment with benznidazole microparticles (50 mg kg-1 day-1). Furthermore, no detectable parasite load measured by quantitative polymerase chain reaction and lower levels of T. cruzi-specific antibodies by enzyme-linked immunosorbent assay were found in those mice. A significant decrease in the inflammation of heart tissue after treatment with these microparticles was observed, in comparison with the inflammatory damage observed in both infected mice treated with raw benznidazole and untreated infected mice. Therefore, these polymeric formulations are an attractive approach to treat Chagas disease.


Assuntos
Doença de Chagas/tratamento farmacológico , Nanopartículas/administração & dosagem , Nitroimidazóis/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Doença Aguda/terapia , Animais , Modelos Animais de Doenças , Feminino , Camundongos
3.
AAPS PharmSciTech ; 22(2): 67, 2021 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-33554316

RESUMO

It is well known that the splitting of tablets can bring serious risks to the health of the treated animals, e.g., the possible adverse reactions caused by overdoses of fenbendazole or aspirin. In this regard, this work aimed to evaluate, for the first time, the splitting behavior of commercial veterinary tablets and identifying the technological aspects that interfere in this process. Tablets were cut in halves using a tablet splitter and were analyzed regarding mass variation, mass loss, friability, and hardness. Microstructural and morphological evaluations were also performed. For most of the tablets, organic flavor additives provided more uniformity and cohesive matrix, which preserved its hardness after the cut and led to subdivision results within acceptable limits for mass measurements and friability. Apart from the microstructure, the most critical technological aspect for a correct splitting performance in such tablets was the presence of a score. Thus, the results presented here allow us to guide the manufacturing of veterinary drug products in order to produce tablets more adapted to the splitting process.


Assuntos
Comprimidos/química , Medicina Veterinária , Animais , Composição de Medicamentos/métodos , Dureza
4.
AAPS PharmSciTech ; 21(3): 112, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32236813

RESUMO

This study was aimed to design a simple and novel prototype device for the production of polymeric microparticles. To prove the effectiveness of this device, benznidazole microparticles using chitosan as carrier and NaOH, KOH, or SLS as counter ions were used. For comparison, benznidazole microparticles were prepared by the conventional dripping technique (syringe and gauge) using the same excipients. Microparticles were characterized in terms of encapsulation efficiency, particle shape, size and surface topography, crystallinity characteristics, thermal behavior, and dissolution rate. Then, the pharmacokinetic parameters were evaluated after the oral administration of the microparticles to healthy Wistar rats. The prepared formulations, by means of this device, showed good drug encapsulation efficiency (> 70%). Release studies revealed an increased dissolution of benznidazole from chitosan microparticles prepared using the novel device. It achieved more than 90% in 60 min, while those of the conventional microparticles and raw drug achieved 65% and 68%, respectively, during the same period. Almost spherical benznidazole microparticles with a smooth surface and size around 10-30 µm were observed using scanning electron microscopy. Thermal analysis and X-ray diffraction studies suggested a partial reduction of drug crystallinity. Moreover, the relative oral bioavailability of the novel benznidazole microparticles showed that the area under the curve for the microencapsulated drug was 10.3 times higher than the raw drug. Thus, these findings indicate that the designed glass prototype device is a useful alternative to formulate benznidazole polymeric microparticles with improved biopharmaceutical properties and could be useful for other therapeutic microparticulate systems.


Assuntos
Composição de Medicamentos/instrumentação , Nitroimidazóis/química , Animais , Quitosana/química , Liberação Controlada de Fármacos , Nitroimidazóis/farmacocinética , Ratos , Ratos Wistar
5.
AAPS PharmSciTech ; 21(1): 16, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31807963

RESUMO

Triclabendazole belongs to the class II/IV of the Biopharmaceuticals Classification System, and its low aqueous solubility represents a major drawback during the development of effective dosage forms. Therefore, the goal of this study was to elucidate whether polymeric solid dispersions would represent a suitable approach to overcome such disadvantage. Due to the lack of information on triclabendazole release, four different dissolution media were evaluated to analyze drug dissolution rate. The polymeric solid dispersions were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The selected final formulations were further stored for 24 months, and their physical stability was evaluated by means of X-ray diffraction and drug dissolution assays. Drug solubility studies indicated that poloxamer 407 (P407) solubilized a higher amount of drug than polyethylene glycol 6000. Drug-to-carrier ratio, nature of the selected carriers, and the type of dissolution media were important factors for increasing dissolution. By infrared spectroscopy, there were no specific interactions between the drug and polymers. The physicochemical characterization of the systems showed a detectable evidence of drug amorphization by increasing the carrier ratio. Micromeritic studies indicated that raw triclabendazole, physical mixtures, and reference formulation showed poor flow properties, in contrast to the triclabendazole:P407 solid dispersion sample. Both the crystalline properties and dissolution rate of selected samples were very similar after 24 months at room temperature. Thus, considering physical stability and dissolution studies, the development of the solid dispersion is a very suitable methodology to improve triclabendazole dissolution and, potentially, its biopharmaceutical performance.


Assuntos
Antiplatelmínticos/química , Sistemas de Liberação de Medicamentos/métodos , Triclabendazol/química , Administração Oral , Antiplatelmínticos/administração & dosagem , Varredura Diferencial de Calorimetria/métodos , Química Farmacêutica/métodos , Cristalização/métodos , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Solubilidade , Espectrofotometria Infravermelho/métodos , Triclabendazol/administração & dosagem , Difração de Raios X/métodos
6.
AAPS PharmSciTech ; 19(5): 2311-2321, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29845501

RESUMO

Triclabendazole is the first-line drug of choice to treat and control fasciolasis, a neglected parasitic human disease. It is a class II/IV compound according to the Biopharmaceutics Classification System. Thus, the aim of this study was to improve aqueous solubility and dissolution rate of triclabendazole complexed with 2-hydroxylpropyl-ß-cyclodextrin (HP-ß-CD) and methyl-ß-cyclodextrin (Me-ß-CD) at 1:1 and 1:2 M ratio. The impact of storage on the solubility, dissolution profile, and solid-state properties of such complexes was also investigated. Drug-carrier interactions were characterized by infrared spectroscopy, differential scanning calorimetry, X-ray diffractometry, and scanning electron microscopy. The solubility of triclabendazole improved up to 256- and 341-fold using HP-ß-CD and Me-ß-CD, respectively. In particular, the drug complexed with Me-ß-CD showed a positive deviation from linearity, suggesting that its solubility increases with an increasing concentration of Me-ß-CD concentration in a nonlinear manner. The drug dissolution was found to be improved through complex formation with HP-ß-CD and Me-ß-CD. In particular, the 1:2 M ratio complexes exhibited higher dissolution than the corresponding 1:1 M ratio complexes. The physicochemical characterization of the systems showed strong evidence of amorphous phases and/or of the formation of an inclusion complex. Stored at 25 °C, 60% RH for 24 months, drug complexed with ß-cyclodextrins (CDs) at 1:2 M ratio remained amorphous. Based on these findings, it is postulated that the formation of triclabendazole-CD inclusion complexes produced significant enhancement in both the dissolution and solid-state properties of the drug, which may lead to the development of triclabendazole novel formulations with improved biopharmaceutical characteristics.


Assuntos
Anti-Helmínticos/química , Benzimidazóis/química , Ciclodextrinas/química , Sistemas de Liberação de Medicamentos/métodos , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/metabolismo , Benzimidazóis/administração & dosagem , Benzimidazóis/metabolismo , Varredura Diferencial de Calorimetria , Ciclodextrinas/administração & dosagem , Ciclodextrinas/metabolismo , Microscopia Eletrônica de Varredura , Solubilidade , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier , Triclabendazol , Difração de Raios X
7.
AAPS PharmSciTech ; 19(3): 1274-1286, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29313262

RESUMO

Praziquantel (PZQ) is the recommended, effective, and safe treatment against all forms of schistosomiasis. Solid dispersions (SDs) in water-soluble polymers have been reported to increase solubility and bioavailability of poorly water-soluble drugs like PZQ, generally due to the amorphous form stabilization. In this work, poloxamer (PLX) 237 and poly(vinylpyrrolidone) (PVP) K30 were evaluated as potential carriers to revert PZQ crystallization. Binary and ternary SDs were prepared by the solvent evaporation method. PZQ solubility increased similarly with PLX either as binary physical mixtures or SDs. Such unpredicted data correlated well with crystalline PZQ and PLX as detected by solid-state NMR (ssNMR) and differential scanning calorimetry in those samples. Ternary PVP/PLX/PZQ SDs showed both ssNMR broad and narrow superimposed signals, thus revealing the presence of amorphous and crystalline PZQ, respectively, and exhibited the highest PZQ dissolution efficiency (up to 82% at 180 min). SDs with PVP provided a promising way to enhance solubility and dissolution rate of PZQ since PLX alone did not prevent recrystallization of amorphous PZQ. Based on ssNMR data, novel evidences on PLX structure and molecular dynamics were also obtained. As shown for the first time using ssNMR, propylene glycol and ethylene glycol constitute the PLX amorphous and crystalline components, respectively.


Assuntos
Anti-Helmínticos/química , Portadores de Fármacos/química , Poloxâmero/química , Povidona/química , Praziquantel/química , Anti-Helmínticos/administração & dosagem , Varredura Diferencial de Calorimetria , Cristalização , Praziquantel/administração & dosagem , Solubilidade
8.
Drug Dev Ind Pharm ; 40(11): 1476-82, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23971494

RESUMO

Encapsulation of albendazole, a class II compound, into polymeric microparticles based on chitosan-sodium lauryl sulfate was investigated as a strategy to improve drug dissolution and oral bioavailability. The microparticles were prepared by spray drying technique and further characterized by means of X-ray powder diffractometry, infrared spectroscopy and scanning electron microscopy. The formation of a novel polymeric structure between chitosan and sodium lauryl sulfate, after the internal or external gelation process, was observed by infrared spectroscopy. The efficiency of encapsulation was found to be between 60 and 85% depending on the internal or external gelation process. Almost spherically spray dried microparticles were observed using scanning electron microscopy. In vitro dissolution results indicated that the microparticles prepared by internal gelation released 8% of the drug within 30 min, while the microparticles prepared by external gelation released 67% within 30 min. It was observed that the AUC and Cmax values of ABZ from microparticles were greatly improved, in comparison with the non-encapsulated drug. In conclusion, the release properties and oral bioavailability of albendazole were greatly improved by using spraydried chitosan-sodium lauryl sulphate microparticles.


Assuntos
Albendazol/química , Anti-Helmínticos/química , Quitosana/química , Dodecilsulfato de Sódio/química , Albendazol/farmacocinética , Animais , Anti-Helmínticos/farmacocinética , Disponibilidade Biológica , Liberação Controlada de Fármacos , Masculino , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Difração de Pó , Ratos , Ratos Wistar , Espectroscopia de Infravermelho com Transformada de Fourier , Tecnologia Farmacêutica
9.
J Pharm Biomed Anal ; 239: 115878, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38039869

RESUMO

Despite nifurtimox (NFX) being a traditional drug for treating Chagas disease, some of its physicochemical properties are still unknown, especially its thermal behavior, which brings important outcomes regarding stability and compatibility. In this work, a comprehensive study of NFX's thermal properties was conducted to assist incremental innovations that can improve the efficacy of this drug in novel pharmaceutical products. For this purpose, thermal analyses associated with spectroscopy and spectrometry techniques were used. DSC analyses revealed that the melt crystallization of the NFX led to its amorphous form with the possible formation of a minor fraction of a different crystalline phase. Coats-Redfern method using TGA results indicated the activation energy of NFX non-isothermal degradation as 348.8 ± 8.2 kJ mol-1, which coincides with the C-NO2 bond dissociation energy of the 2-nitrofuran. Investigation of the isothermal degradation kinetics using FTIR 2D COS showed the possible detachment of radical NO2 and ethylene from the NFX structure, which could affect its mechanism of action. A preliminary mechanism for the thermal degradation of this drug was also proposed. The results enhanced the understanding of NFX's thermal properties, providing valuable insights, especially for developing NFX-based pharmaceutical products that involve thermal processing.


Assuntos
Nifurtimox , Nitrofuranos , Nifurtimox/metabolismo , Nifurtimox/uso terapêutico , Cristalização , Dióxido de Nitrogênio , Preparações Farmacêuticas
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 316: 124346, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38692105

RESUMO

Considering the health relevance of Chagas' disease, recent research efforts have focused on developing more efficient drug delivery systems containing nifurtimox (NFX). This paper comprehensively investigates NFX through conformational analysis and spectroscopic characterization. Using a conformer-rotamer ensemble sampling tool (CREST-xtb), five distinct conformers of NFX were sampled within a 3.0 kcal mol-1 relative energy window. Subsequently, such structures were used as inputs for geometry optimization by density functional theory (DFT) at B3LYP-def2-TZVP level of theory. Notably, harmonic vibrational frequencies were calculated to establish an in-depth comparison with experimental results and existing literature for the NFX or similar molecules and functional groups, thereby achieving a widely reasoned assignment of the mid-infrared band absorptions for the first time. Moreover, UV-VIS spectra of NFX were obtained in several solvents, enabling the determination of the molar absorptivity coefficient for the two electronic transitions observed for NFX. Among the aprotic solvents, a bathochromic effect was observed in the function of the dielectric constants. Furthermore, a hypochromic effect was observed when the drug was dissolved in protic solvents. These findings offer crucial support for new drug delivery systems containing NFX while demonstrating the potential of spectrophotometric studies in establishing quality control assays for NFX drug products.


Assuntos
Doença de Chagas , Conformação Molecular , Nifurtimox , Doença de Chagas/tratamento farmacológico , Nifurtimox/química , Espectrofotometria Ultravioleta , Tripanossomicidas/química , Modelos Moleculares , Teoria da Densidade Funcional , Trypanosoma cruzi/efeitos dos fármacos , Solventes/química
11.
AAPS PharmSciTech ; 14(1): 64-73, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23225117

RESUMO

The objective of the present paper was the development and the full characterization of antifungal films. Econazole nitrate (ECN) was loaded in a polymeric matrix formed by chitosan (CH) and carbopol 971NF (CB). Polyethylene glycol 400 and sorbitol were used as plasticizing agents. The mechanical properties of films were poorer when the drug was loaded, probably because crystals of ENC produces network outages and therefore reduces the polymeric interactions between the polymers. Polymers-ECN and CH-CB interactions were analyzed by Fourier-transform infrared spectroscopy (FTIR), thermal gravimetry analysis, and differential thermal analysis (DTA-TGA). ECN did not show structure alterations when loaded into the films. In scanning electron microphotographs and atomic force microscopy analysis, films prepared with CB showed an evident wrinkle pattern probably due to the strong interactions between the polymers, which were observed by FTIR and DTA-TGA. The in vitro activity of the formulations against Candida krusei and Candida parapsilosis was twice as greater as the commercial cream, probably as a result of the antifungal combination of the drug with the CH activity. All these results suggest that these polymeric films containing ECN are potential candidates in view of alternatives dosages forms for the treatment of the yeast assayed.


Assuntos
Antifúngicos/farmacologia , Polímeros/farmacologia , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Técnicas In Vitro , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
12.
J Food Sci ; 88(4): 1495-1505, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36939001

RESUMO

Probiotics are live microorganisms that confer beneficial effects on the health of the host if administered in adequate amounts (106  CFU viable microorganisms/g of food). As the most frequent route of administration of these microorganisms is oral, the number of them that remains viable through the gastrointestinal tract decreases substantially. Thus, in this research work, we developed a series of alginate-based microparticles using different adjuvants such as methylcellulose, carboxymethylcellulose, chitosan, carbopol, ß-cyclodextrin, starch, carrageenan, and Eudragit® RS 100 as carriers for improving the survival of Lactococcus lactis. The alginate-based formulations exhibited very good drug encapsulation efficiency, up to 90%. Release studies from selected microparticles revealed that almost 100% of bacteria were in solution at 30 min. By scanning electron microscopy, irregular nonporous particles with a size between 200 and 500 µm were seen. In particular, microparticles formulated with alginate-carboxymethylcellulose and alginate-methylcellulose exhibited the best protection for the bacterial cells against both simulated gastric juice and simulated intestinal juice. In addition, those microparticulate systems were able to maintain the viability of the encapsulated bacteria in large numbers for at least 24 weeks. Thus, the present study confirmed that these alginate-based microparticles are a valuable approach for keeping the viability and storage stability of L. lactis.


Assuntos
Lactococcus lactis , Probióticos , Carboximetilcelulose Sódica , Trato Gastrointestinal/microbiologia , Composição de Medicamentos , Alginatos
13.
Int J Pharm ; 642: 123120, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37307960

RESUMO

Benznidazole, a poorly soluble in water drug, is the first-line medication for the treatment of Chagas disease, but long treatment periods at high dosages cause several adverse effects with insufficient activity in the chronic phase. According to these facts, there is a serious need for novel benznidazole formulations for improving the chemotherapy of Chagas disease. Thus, this work aimed to incorporate benznidazole into lipid nanocapsules for improving its solubility, dissolution rate in different media, and permeability. Lipid nanocapsules were prepared by the phase inversion technique and were fully characterized. Three formulations were obtained with a diameter of 30, 50, and 100 nm and monomodal size distribution with a low polydispersity index and almost neutral zeta potential. Drug encapsulation efficiency was between 83 and 92 % and the drug loading was between 0.66 and 1.04 %. Loaded formulations were stable under storage for one year at 4 °C. Lipid nanocapsules were found to protect benznidazole in simulated gastric fluid and provide a sustained release platform for the drug in a simulated intestinal fluid containing pancreatic enzymes. The small size and the almost neutral surface charge of these lipid nanocarriers improved their penetration through mucus and such formulations showed a reduced chemical interaction with gastric mucin glycoproteins. LNCs. The incorporation of benznidazole in lipid nanocapsules improved the drug permeability across intestinal epithelium by 10-fold compared with the non-encapsulated drug while the exposure of the cell monolayers to these nanoformulations did not affect the integrity of the epithelium.


Assuntos
Nanocápsulas , Nanocápsulas/química , Liberação Controlada de Fármacos , Lipídeos/química , Permeabilidade , Estabilidade de Medicamentos
14.
Colloids Surf B Biointerfaces ; 217: 112678, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35816885

RESUMO

Chagas disease is a neglected tropical disease affecting the American continent and also some regions of Europe. Benznidazole, approved by FDA, is a drug of choice but its poor aqueous solubility may lead to a low bioavailability and efficacy. Therefore, the aim of this study was to formulate nanoparticles of benznidazole for improving its solubility, dissolution and permeability. A Plackett-Burman design was applied to identify the effect of 5 factors over 4 responses. Then, a Central Composite design was applied to estimate the values of the most important factors leading to the best compromise between highest nanoprecipitation efficiency, drug solubility and lower particle size. The optimized nanoparticles were evaluated for in vitro drug release in biorelevant media, stability studies and transmission electron microscopy. Biocompatibility and permeability of nanoparticles were evaluated on the Caco-2 cell line. The findings of the optimization process indicated that concentration of drug and stabilizer influenced significantly the particle size while concentration of stabilizer and organic/water phase volume ratio mainly influenced the drug solubility. Stability studies suggested that benznidazole nanoparticles were stable after 12 months at different temperatures. Minimal interactions of those nanoparticles and mucin glycoproteins suggested favorable properties to address the intestinal mucus barrier. Cell viability studies confirmed the safety profile of the optimized formulation and showed an increased permeation through the Caco-2 cells. Thus, this study confirmed the suitability of the design of experiment and optimization approach to elucidate critical parameters influencing the quality of benznidazole nanoparticles, which could lead to a more efficient management of Chagas disease by oral route.


Assuntos
Doença de Chagas , Nanopartículas , Nitroimidazóis , Administração Oral , Disponibilidade Biológica , Células CACO-2 , Doença de Chagas/tratamento farmacológico , Humanos , Nitroimidazóis/farmacologia , Nitroimidazóis/uso terapêutico , Tamanho da Partícula , Solubilidade
15.
Pharm Dev Technol ; 15(2): 184-91, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19621984

RESUMO

Prednisone is considered the glucocorticoid of choice for anti-inflammatory and immunosuppressant effects. However, its very low aqueous solubility can compromise oral bioavailability. Changes in the dissolution of a prednisone-PEG 6000 solid dispersion into capsule were investigated by addition of pregelatinized starch. Physical state of prednisone:PEG 6000 was analyzed by X-ray diffractometry, and scanning electron microscopy. Capsule formulations containing prednisone-PEG 6000 and pregelatinized starch showed superior dissolution properties (> 95% in 60 min) when compared with reference capsules without disintegrant (< 45% in 60 min). Water uptake and disintegration time were directly correlated with pregelatinized starch amount. The morphology of prednisone-PEG 6000 particles with disintegrant was analyzed by SEM, showing a novel surface structure. Thus, solid dispersions of a poorly water soluble drug combined with a disintegrant were confirmed as a valid approach to the improvement of drug dissolution.


Assuntos
Portadores de Fármacos/química , Glucocorticoides/administração & dosagem , Polietilenoglicóis/química , Prednisona/administração & dosagem , Disponibilidade Biológica , Cápsulas , Química Farmacêutica , Excipientes/química , Géis , Glucocorticoides/química , Glucocorticoides/farmacocinética , Microscopia Eletrônica de Varredura , Prednisona/química , Prednisona/farmacocinética , Solubilidade , Amido/química , Fatores de Tempo , Água/química , Difração de Raios X
16.
Pharm Dev Technol ; 15(2): 162-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19589124

RESUMO

Diclofenac sodium is a non-steroidal anti-inflammatory drug widely used in the treatment of ankylosing spondylitis, rheumatoid arthritis and osteoarthritis. In this context, a rapid onset of action is required. Thus, the aim of this study was to formulate diclofenac sodium-PVP K-30 fast release tablets from solid dispersions. The physical state and drug:carrier interactions were analyzed by X-ray diffraction and scanning electron microscopy and stability upon storage was also studied. Dissolution rate of diclofenac sodium from solid dispersions was markedly enhanced by increasing the polymer concentration.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Diclofenaco/administração & dosagem , Portadores de Fármacos/química , Povidona/química , Anti-Inflamatórios não Esteroides/química , Diclofenaco/química , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Solubilidade , Comprimidos , Fatores de Tempo
17.
J Antimicrob Chemother ; 64(2): 375-8, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19497941

RESUMO

OBJECTIVES: In vitro and in vivo experiments were used to determine whether albendazole-PEG 6000 solid dispersions would be effective in the treatment of Toxocara canis larva migrans. METHODS: Albendazole-PEG 6000 (1:1, 1:5 and 1:9 ratios) solid dispersions were prepared by the solvent evaporation method. The morphology of the particles was evaluated by scanning electron microsocopy (SEM), and in vitro dissolution assays were also carried out. Mice were infected with T. canis and then treated orally with albendazole-PEG 6000 systems or albendazole suspended in water. The anthelmintic effect was examined at 28 days post-infection (p.i.). The number of larvae recovered from mice treated with albendazole alone and those treated with albendazole-PEG 6000 were compared with the numbers from the placebo group. RESULTS: Dissolution of albendazole from solid dispersions was markedly enhanced by increasing the polymer concentration. At a 1:9 drug:polymer ratio, >90% of the albendazole was dissolved in 10 min. SEM showed microparticles to be of small spherical shape compared with the pure components. In vivo evaluation of larva migration showed that both albendazole-PEG 6000 solutions exhibited a greater anthelmintic effect in the brain (0 larvae/mouse). In addition it was also found that liver and lung showed a significant decrease in the number of larvae. Evaluation of vehicle toxicity (PEG 6000 in water) showed a mice survival rate of 100% at the assayed concentrations. CONCLUSIONS: These data suggest that albendazole-PEG 6000 solid dispersions markedly increased the effectiveness of albendazole against the migratory activity of larvae. Particularly, these polymeric solutions were able to totally prevent migration of larvae to the mouse brain.


Assuntos
Albendazol/uso terapêutico , Anti-Helmínticos/uso terapêutico , Larva Migrans/tratamento farmacológico , Polietilenoglicóis/uso terapêutico , Toxocaríase/tratamento farmacológico , Administração Oral , Albendazol/administração & dosagem , Animais , Encéfalo/parasitologia , Humanos , Camundongos , Polietilenoglicóis/administração & dosagem , Toxocara canis/efeitos dos fármacos
19.
Colloids Surf B Biointerfaces ; 177: 169-177, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30731393

RESUMO

Benznidazole (BNZ) is the drug of choice for the treatment of Chagas disease in many countries. However, its low water solubility produces low and/or variable oral bioavailability. Thus, the aim of this work was to formulate micro- and nanoparticles based on Eudragit® RS PO and Eudragit® RL PO as a convenient approach to increase the dissolution rate of BNZ. The microparticles were obtained by means of spray-drying process while the nanoparticles were prepared through the nanoprecipitation technique and further freeze-drying. The results indicated that nanoparticles were obtained in 86% yield while microparticles were obtained in 68% yield. In both cases, the encapsulation efficiency of particles was greater than 78% while drug loading capacity was nearly 24% w/w and 18% w/w, after spray-drying and freeze-drying procedures, respectively. Images of scanning electron microscopy showed that the particles obtained by spray-drying and freeze-drying were in the micrometer and nanometer scale, respectively. FT-IR spectra of BNZ-loaded particles obtained by both methods showed characteristic bands of BNZ confirming that part of drug remained on their surface. Thermal analysis revealed that the drug crystallinity after both methods decreased. Physical stability evaluation of the nanoparticles confirmed that Pluronic® F68 was suitable to keep the particles size in a range of 300 nm after 70 days storage at 4 ± 2 °C. In-vitro release studies showed increased dissolution rate of drug from the particles obtained by both methods respect to untreated BNZ. The kinetics of drug release in acid media followed the Higuchi kinetics indicating drug diffusion mechanism from particles.


Assuntos
Doença de Chagas/tratamento farmacológico , Imunossupressores/química , Imunossupressores/uso terapêutico , Nanopartículas/química , Nitroimidazóis/química , Nitroimidazóis/uso terapêutico , Criança , Liberação Controlada de Fármacos , Humanos , Hidrodinâmica , Imunossupressores/síntese química , Cinética , Nitroimidazóis/síntese química , Tamanho da Partícula , Propriedades de Superfície
20.
Acta Trop ; 198: 105080, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31299283

RESUMO

Neglected tropical diseases (NTDs) constitute a group of infectious diseases prevalent in countries with tropical and subtropical climate that affect the poorest individuals and produce high chronic disability associated with serious problems for the health system and socioeconomic development. Chagas disease or American trypanosomiasis is included on the NTDs list. However, even though this disease affects more than 10 million people, mostly in Latin America, causing the death of over 10,000 people every year, only two drugs are approved for its treatment, benznidazole and nifurtimox. These antiparasitic agents were developed almost half a century ago and present several biopharmaceutical disadvantages such as low aqueous solubility and permeability limiting their bioavailability. In addition, both therapeutic agents are available only as tablets and a liquid pediatric formulation is still lacking. Therefore, novel pharmaceutical strategies to optimize the pharmacotherapy of Chagas disease are urgently required. In this regard, nanotechnological approaches may be a crucial alternative for the delivery of both drugs ensuring an effective pharmacotherapy although the successful bench-to-bedside translation remains a major challenge. The present work reviews in detail the formulation and in-vitro/in-vivo analysis of different nanoformulations of nifurtimox and benznidazole in order to enhance their solubility, dissolution, bioavailability and trypanocidal activity.


Assuntos
Doença de Chagas/tratamento farmacológico , Nanoestruturas , Nifurtimox/uso terapêutico , Nitroimidazóis/uso terapêutico , Tripanossomicidas/uso terapêutico , Formas de Dosagem , Humanos , Nifurtimox/administração & dosagem , Nifurtimox/química , Nitroimidazóis/administração & dosagem , Nitroimidazóis/química , Tripanossomicidas/administração & dosagem , Tripanossomicidas/química
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