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1.
Int J Pharm ; 462(1-2): 44-51, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24378329

RESUMO

In the treatment of mild to medium severe atopic dermatitis a new formulation proved to be highly efficient. The formulation is based on a combination of microsilver and nanolipid carriers (NLC) incorporated into an o/w cream and a lotion. A theory of action was proposed, the formation of silver-NLC complex (sNLC). In this study this theory was proven, and based on this new mechanism two new approaches for dealing with AD are suggested to distinctly improve AD treatment, i.e. increasing efficiency, reducing drug exposure and reducing side effects. The antimicrobial silver ions adsorb onto the surface of the negatively charged NLC (=sNLC complex). The sNLC as nanoparticles are highly adhesive to skin and bacterial surfaces, leading to a locally high concentration of silver ions killing the bacteria, much more effective than silver alone. The NLC restore the distorted skin barrier. Based on this a new two-step approach is suggested: (1) "treatment-supportive consumer care" by restoring the normal skin condition (NLC for barrier restoration plus synergistic antibacterial silver-NLC complex) and (2) "drug-loaded consumer care AD formulations". i.e. incorporating drugs into the NLC of this consumer care formulation. NLC incorporation makes the drugs more effective (penetration enhancement) and simultaneously exploits the skin normalization ability of the skin care sNLC formulation, future drug candidates being prednicarbate and tacrolimus.


Assuntos
Dermatite Atópica/tratamento farmacológico , Lipídeos/química , Nanopartículas , Prata/administração & dosagem , Adesividade , Animais , Antibacterianos/administração & dosagem , Antibacterianos/efeitos adversos , Antibacterianos/química , Dermatite Atópica/microbiologia , Dermatite Atópica/patologia , Modelos Animais de Doenças , Portadores de Fármacos/química , Feminino , Humanos , Camundongos , Tamanho da Partícula , Prata/efeitos adversos , Prata/química , Pele/metabolismo , Pele/patologia , Absorção Cutânea
2.
Pharmazie ; 68(9): 723-31, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24147340

RESUMO

Nanostructured lipid carriers (NLC) were developed using a skin-compatible surfactant and natural lipid materials (rice oil, cholesterol) to incorporate lycopene. Characteristics of the NLC were explored in comparison with nanoemulsions and solid-lipid nanoparticles (SLN). Photon correlation spectroscopy, laser diffractometry (LD) and differential scanning calorimetry were used to determine particle size and thermal stability. Particle size expressed as LD (0.99) was 405 nm for the SLN, 350 nm for the NLC without cholesterol and 287 nm for the NLC with cholesterol. Rice oil and cholesterol enabled the formation of smaller particles, but cholesterol also reduced drug stability in the NLC. To preserve chemical stability of lycopene in the NLC, cholesterol should be avoided and storage should be at 4 degrees C or at room temperature.


Assuntos
Anticolesterolemiantes/química , Antioxidantes/administração & dosagem , Carotenoides/administração & dosagem , Colesterol/química , Óleos de Plantas/química , Varredura Diferencial de Calorimetria , Química Farmacêutica , Portadores de Fármacos , Composição de Medicamentos , Estabilidade de Medicamentos , Eletroquímica , Excipientes , Lipídeos/química , Licopeno , Nanoestruturas , Tamanho da Partícula , Óleo de Farelo de Arroz
3.
Drug Discov Ther ; 6(5): 249-55, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23229145

RESUMO

The aim of the present study was to enhance the cholinesterase inhibitory activity of Zingiber cassumunar (ZC) oil using a microemulsion (ME) technique. Pseudoternary phase diagrams of the oil, water, and surfactant/co-surfactant mixture were constructed using a water titration method. Effects of co-surfactant, surfactant/co-surfactant ratio, ionic strength, and pH were examined by means of the microemulsion region which existed in the phase diagrams. The inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were tested by Ellman's colorimetric assay. It was found that ZC oil possesses inhibitory activity against not only AChE but also BChE. Formulation of ZC oil as ME revealed that alkyl chain length and number of hydroxyl groups of co-surfactant exhibited a remarkable effect on the pseudoternary phase diagram. Longer alkyl chains and more hydroxyl groups gave smaller regions of MEs. Ionic strength also affected the ME region. However, the phase behavior was hardly influenced by pH. The suitable ZC oil ME was composed of Triton X-114 in combination with propylene glycol. The anti-cholinesterase activity of this ME was much higher than that of native ZC oil. It exhibited twenty times and twenty five times higher inhibitory activity against AChE and BChE, respectively. ZC oil loaded ME is an attractive formulation for further characterization and an in vivo study in an animal model with Alzheimer's disease.


Assuntos
Inibidores da Colinesterase/farmacologia , Óleos Voláteis/farmacologia , Zingiberaceae , Acetilcolinesterase/metabolismo , Butirilcolinesterase/metabolismo , Química Farmacêutica , Inibidores da Colinesterase/química , Inibidores da Colinesterase/isolamento & purificação , Colorimetria , Emulsões , Concentração de Íons de Hidrogênio , Octoxinol , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Concentração Osmolar , Plantas Medicinais , Polietilenoglicóis/química , Propilenoglicol/química , Rizoma , Tensoativos/química , Água/química , Zingiberaceae/química
4.
Drug Discov Ther ; 6(1): 38-43, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22460427

RESUMO

In the present study, quercetin (QT), morin (MR), and quercetin-3-O-glucopyranoside (QG) isolated from guava leaves were comparatively tested for antioxidant activity using DPPH, ABTS, and FRAP methods. QT was the most active among them. The free radical scavenging activity of QT was approximately four times higher than MR and two times higher than QG. The reducing power of QT was eight times higher than MR and two times higher than QG. A mixture of QT with MR or QG showed interesting combination effect. The synergistic antioxidant activity was obtained when QT was mixed with MR whereas the antagonistic effect was found when mixed with QG. The stability study of QT in liquid preparations indicated that the decomposition reaction rate of QT could be explained by a kinetic model assuming a first-order chemical reaction. The aqueous solution of QT was rapidly decomposed with t1/2 of approximately five days whereas QT entrapped in chitosan nanoparticles was five times longer. It was concluded that QT was the most active antioxidant from guava leaves. Entrapment of QT in chitosan nanoparticles could significantly enhance its stability.


Assuntos
Antioxidantes/farmacologia , Flavonoides/farmacologia , Psidium/química , Quercetina/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Quitosana/química , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Sinergismo Farmacológico , Flavonoides/química , Flavonoides/isolamento & purificação , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Glucosídeos/isolamento & purificação , Glucosídeos/farmacologia , Meia-Vida , Modelos Químicos , Nanopartículas , Folhas de Planta , Quercetina/análogos & derivados , Quercetina/química , Quercetina/isolamento & purificação , Fatores de Tempo
5.
Drug Discov Ther ; 5(1): 12-7, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22466091

RESUMO

In this study, Sesbania grandiflora, a plant in the Leguminosae family, was investigated for its antibacterial activities. The agar well diffusion assay as well as the agar and broth dilution assays were used for determination of antibacterial activities. The crude ethanolic extracts obtained from different parts of this plant exhibited different potent activities. The stem bark has the most potential to yield an extract with the highest antibacterial action. The fractionation of the stem bark with different solvents indicated that the fractionated extracts obtained from ethyl acetate or butanol possessed the most pronounced antibacterial activity. The kinetic study of bactericidal activities revealed that the butanol fractionated extract of the stem bark was effective against Gram negative bacteria. This study suggests that the stem bark of S. grandiflora contains promising antibacterial substances for clinical purposes.

6.
Drug Discov Ther ; 5(2): 84-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22466145

RESUMO

The use of natural antimicrobial agents is garnering attention due to consumer and producer awareness of health problems. This study found that the essential oil of A. galanga had strong bactericidal activity against both Gram-negative and Gram-positive bacteria. The bactericidal action of A. galanga oil was extremely rapid. Results of scanning electron microscopy observations suggested that A. galanga oil had antibacterial action probably as a result of its modification of the bacterial cell membrane, disrupting the membrane's permeability. This study suggested that the essential oil of A. galanga shows promise as a natural antimicrobial agent for use as a food preservative.

7.
Drug Discov Ther ; 5(3): 144-9, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22466244

RESUMO

This work was undertaken to explore antityrosinase and antioxidant activities of twenty essential oils of edible Thai plants. Antityrosinase activity against mushroom tyrosinase was examined by means of the dopachrome method using L-dopa as an enzymatic substrate. The essential oil of Cymbopogon citratus had the highest level of antityrosinase activity, followed by that of Ocimum canum with enzymatic inhibition of 69 ± 4 and 66 ± 3%. GC-MS revealed that geranial and neral were the two most abundant components of their chemical compositions. Antioxidant activity was gauged by the free radical scavenging activity test and ferric reducing/antioxidant power assay. The essential oil of Ocimum sanctum had the highest level of antioxidant activity, followed by the essential oil of Ocimum gratissimum. These results led to the conclusions that the essential oils of edible Thai plants exhibit important biological activities and are a promising choice as natural active ingredients because of their antityrosinase and antioxidant activities.

8.
Drug Discov Ther ; 5(5): 246-52, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22466371

RESUMO

The aim of this study is to develop a microemulsion product from a plant essential oil having the highest anti-tyrosinase activity. The in vitro anti-tyrosinase activity of six essential oils extracted from six edible plants was compared. The oil of Cymbopogon citratus demonstrated the highest activity which was significantly nontoxic to normal human cells. The GC-MS data indicated that geranial and neral are the major compounds in the oil. The phase diagram composed of C. citrates oil, water, and surfactant mixture was conducted by a titration method. Ethyl alcohol was found to be the most suitable cosurfactant for the C. citrates oil microemulsion. The results revealed that the amount of oil and water played an important role in microemulsion conductivity and type. The most desirable o/w type of C. citratus oil microemulsion was found to be composed of 20% oil, 30% water, and 50% surfactant mixture of a 2:1 weight ratio of Tween 20 and ethyl alcohol.

9.
Int J Cosmet Sci ; 32(5): 340-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20384903

RESUMO

Echinacea purpurea contains many beneficial constituents for protection of skin from oxidative stress and for improving hydration of skin. This study aimed to investigate the stability and dermatological efficacy of E. purpurea cream and gel. Echinacea purpurea extract was incorporated into suitable cream and gel bases. Stability of the extract in the formulations was investigated by determining its residual total phenolic content and antioxidant activity after storage at 4°C, 30°C and 40°C for 6 months. The effect of those formulations on skin irritation, hydration level and wrinkle reduction was evaluated in 10 healthy volunteers, aged 25-40 years. The shelf lives of E. purpurea cream and gel in terms of total phenolic content and antioxidant activity were only 2 and 4 months respectively at 4°C and could be extended up to 7 months by incorporation of α-tocopherol or disodium editate. The corneometer hydration indices increased up to 10.6 AU and 11.4 AU, and the wrinkles decreased 9.47% and 14.92% because of the application of E. purpurea cream and gel for 1 month. Both formulations showed no irritation to skin. Echinacea purpurea cream and gel developed in this study were effective in improving skin hydration and reducing wrinkle, but showed low storage stability.


Assuntos
Fármacos Dermatológicos/farmacologia , Echinacea/química , Extratos Vegetais/farmacologia , Pele/efeitos dos fármacos , Antioxidantes/administração & dosagem , Antioxidantes/farmacologia , Humanos , Extratos Vegetais/administração & dosagem , Pele/efeitos da radiação , Raios Ultravioleta/efeitos adversos
10.
Kyobu Geka ; 62(12): 1035-8, 2009 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-19894565

RESUMO

Recently, open stent-grafting has been employed for distal arch aneurysm. However, several complications have been reported. We have used a new delivery system (CLATE) in 8 patients who underwent open stent-grafting. The advantage of CLATE is that it is flexible, and can freely change its shape. Using this delivery system, stent graft is hard to dislocate, and can be delivered at the target site accurately. Therefore, CLATE is considerd to be able to prevent aortic wall injury, peripheral embolic complication and paraplegia.


Assuntos
Aneurisma da Aorta Torácica/cirurgia , Prótese Vascular , Procedimentos Cirúrgicos Cardiovasculares/instrumentação , Stents , Humanos
11.
Kyobu Geka ; 62(6): 492-5, 2009 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-19522212

RESUMO

A 31-year-old man with systemic lupus erythematosus had received long term steroid therapy. He had no compliant, but magnetic resonance imaging showed aortic dissection and annulo-aortic ectasia. Echocardiogram showed severe aortic regurgitation. Therefore aortic root replacement was performed. A histological study of the aortic wall demonstrated myxomatous degeneration in the media. He recovered uneventfully, except for receiving continious hemodia filtration during 4 days after the operation


Assuntos
Aneurisma Aórtico/etiologia , Aneurisma Aórtico/cirurgia , Dissecção Aórtica/etiologia , Dissecção Aórtica/cirurgia , Valva Aórtica/patologia , Valva Aórtica/cirurgia , Lúpus Eritematoso Sistêmico/complicações , Adulto , Dissecção Aórtica/diagnóstico , Aneurisma Aórtico/diagnóstico , Insuficiência da Valva Aórtica/diagnóstico , Insuficiência da Valva Aórtica/etiologia , Insuficiência da Valva Aórtica/cirurgia , Diagnóstico por Imagem , Dilatação Patológica/diagnóstico , Dilatação Patológica/etiologia , Dilatação Patológica/cirurgia , Implante de Prótese de Valva Cardíaca , Humanos , Masculino
12.
Kyobu Geka ; 62(4): 336-9, 2009 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-19348221

RESUMO

A 59-year-old man was admitted to our hospital because of angina pectoris and a large right coronary aneurysm. Two years previously, he underwent percutaneous coronary balloon angioplasty for a stenotic lesion in right coronary artery (RCA) #3. Angiography and computed tomography showed a large right coronary aneurysm. On-pump coronary artery bypass grafting (CABG), ligation of RCA proximal and distal to the aneurysm, resection of the aneurysm was performed successfully. Postoperative course was uneventful with satisfactory angiographic results.


Assuntos
Angioplastia Coronária com Balão/efeitos adversos , Aneurisma Coronário/etiologia , Aneurisma Coronário/cirurgia , Infarto do Miocárdio/terapia , Aneurisma Coronário/diagnóstico , Ponte de Artéria Coronária , Diagnóstico por Imagem , Humanos , Ligadura , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
13.
Kyobu Geka ; 62(3): 241-5, 2009 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-19280959

RESUMO

A 65-year-old man was admitted to the hospital because of effort chest pain, 8 years after he received coronary artery bypass grafting [CABG: left internal thoracic artery (LITA) to left anterior descending artery (LAD), saphenous vein graft (SVG) to first diagonal branch (D1) and SVG to postero-lateral branch (PL)]. Emergent coronary angiography revealed right coronary artery occlusion with well patent bypass grafts. Percutaneus coronary intervention (PCI) was performed successfully, but 9 hours later, ventricular septal perforation (VSP) was occurred. Swan-Ganz catheter revealed that pulmonary to systemic blood flow ratio (Qp/Qs) was 2.6. In spite of intensive medical care, his hemodynamics was gradually exacerbated. Subsequent intracavitary repair with equine pericardial patch, sutured using interrupted mattress sutures with felt pledgets, was performed. He had an uneventful recovery thereafter, extubated and weaned from an intra-aortic balloon pumping at the 1st day. He was discharged from hospital on the 27th postoperative day.


Assuntos
Infarto do Miocárdio/complicações , Ruptura do Septo Ventricular/etiologia , Ruptura do Septo Ventricular/cirurgia , Angina Pectoris/cirurgia , Angioplastia Coronária com Balão , Procedimentos Cirúrgicos Cardíacos , Ponte de Artéria Coronária , Humanos , Masculino , Infarto do Miocárdio/terapia , Fatores de Tempo , Resultado do Tratamento
14.
Kyobu Geka ; 62(2): 96-100, 2009 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-19202926

RESUMO

We report 3 cases of endovascular stent-grafting (ESG) for mycotic thoracic aortic aneurysm. The case 1 was a rupture of pseudoaneurysm of the descending aorta caused by mediastinitis due to perforation of esophageal ulcer. The patient underwent emergent ESG for temporary control of the rupture. He underwent esophagus reconstruction 5 month after ESG. The case 2 was admitted due to inflammatory reaction. She was diagnosed with mycotic descending aortic aneurysm and underwent elective ESG because of her old age. Her postoperative course was uneventful and no infection recurred. The case 3 underwent ESG for a ruptured mycotic descending aortic aneurysm. But 113 days after ESG, he underwent ESG again for a ruptured endoleak of the stentgraft. His blood culture demonstrated methillin-resistant Staphylococcus aureus (MRSA). He died of rupture to bronchus and esophagus at 18th day after ESG. We believe that ESG is useful in high risk patients for temporary management of the rupture.


Assuntos
Falso Aneurisma/cirurgia , Aneurisma Infectado/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Ruptura Aórtica/cirurgia , Implante de Prótese Vascular/métodos , Stents , Adulto , Idoso de 80 Anos ou mais , Evolução Fatal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
15.
Kyobu Geka ; 61(9): 748-53, 2008 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-18697454

RESUMO

We report a patient with Marfan syndrome who received successful 7 consecutive operations during 11 years. She underwent descending aortic replacement for chronic type B dissection at the age of 24. Mitral valve replacement (MVR) was performed for mitral regurgitation (MR) at the age of 30, and abdominal aortic replacement was done for persistent dissection at the age of 31, aortic root and arch replacement was done at the age of 34. The 9 months later, she received re-MVR for dysfunction of bioprosthesis and tricuspid valve anuloplasty (TAP) for tricuspid regurgitation (TR). But severe paravalvuler leakage of mitral valve necessitated direct closure of detachment. Thoracoabdominal replacement was performed for rupture of persistent dissection at the age of 35. She was discharged on the 54th day after the 7th surgery.


Assuntos
Síndrome de Marfan/cirurgia , Adulto , Dissecção Aórtica/cirurgia , Aorta Torácica/cirurgia , Aneurisma Aórtico/cirurgia , Feminino , Humanos , Insuficiência da Valva Mitral/cirurgia , Reoperação , Valva Tricúspide/cirurgia
16.
Kyobu Geka ; 61(3): 238-41, 2008 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-18323192

RESUMO

A 74-year-old man had pustulant bilateral arthritis complicated with sepsis and disseminated intravascular coagulation (DIC). Microbiologic study of blood sample showed Streptococcus and methicillin resistant Staphylococcus aureus (MRSA). He was complicated with postulant diskitis since then. Medical treatment for DIC and administration of antibiotics were performed. Preoperative echocardiography revealed massive aortic regurgitation and vegetation of aortic valve, moderate pulmonary regurgitation and vegetation of pulmonary valve, massive mitral regurgitation, massive tricuspid regurgitation. He was diagnosed as infective quadruple valve endocarditis. He received aortic valve replacement, pulmonary valve replacement, mitral valve repair and tricuspid valve repair. Postoperative echocardiography showed satisfactory function of bioprosthesis. Postoperative course was uneventful.


Assuntos
Endocardite/cirurgia , Doenças das Valvas Cardíacas/cirurgia , Valvas Cardíacas/cirurgia , Idoso , Endocardite/microbiologia , Doenças das Valvas Cardíacas/microbiologia , Implante de Prótese de Valva Cardíaca , Humanos , Masculino , Resistência a Meticilina , Índice de Gravidade de Doença , Infecções Estafilocócicas , Infecções Estreptocócicas , Resultado do Tratamento
17.
Drug Dev Ind Pharm ; 30(4): 347-57, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15132177

RESUMO

The current research study is based on the design and development of a sol-gel biodegradable controlled-release formulation for use in the treatment of periodontal diseases. Glycerylmonooleate (GMO) was used as a main composition in the gel base. The influence of various additives, e.g., glycerylmonostearate (GMS), methylcellulose (MC), surfactants, and triglycerides, in GMO formulations on rheologic and swelling properties and release characteristics was described. It was demonstrated that the surfactants and triglycerides affected rheologic behavior, whereas GMS and MC influenced both rheologic and swelling properties of the bases. The release study revealed that drug released from the gel bases depended on the square root of time. The kinetics can be explained by the Higuchi's diffusion theory. Some polyols could enhance drug release from the gel. The stability results suggested that the dental gels obtained should be kept in the low temperature range.


Assuntos
Antibacterianos/administração & dosagem , Antibacterianos/química , Glicerídeos/química , Tetraciclina/administração & dosagem , Tetraciclina/química , Preparações de Ação Retardada , Estabilidade de Medicamentos , Excipientes , Géis , Periodontite/tratamento farmacológico , Reologia , Solubilidade , Tecnologia Farmacêutica , Temperatura
18.
Drug Dev Ind Pharm ; 27(8): 819-23, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11699833

RESUMO

The objective of this study was to clarify the thermal behavior of ursodeoxycholic acid (UDCA) in mixtures with urea. Physical mixtures of UDCA and urea in various ratios were prepared, and the thermal analysis of these sample mixtures was investigated using conventional differential scanning calorimetry (DSC) and variable-temperature powder X-ray diffractometry (VTXRD). The hot-stage microscopy (HSM) and powder X-ray diffractometry (PXRD) were used as complementary techniques. From the DSC results of all sample mixtures, it was found that there was no endothermic peak at the melting temperature of intact UDCA crystals. The DSC thermograms of each ratio showed only the endothermic peak at about 136 degrees C due to the melt of urea and the anomalous endothermic peak at about 155 degrees C 157 degrees C. The VTXRD study revealed that the crystals of urea completely disappeared at a temperature of 140 degrees C. At this temperature, it was identified that the VTXRD pattern obtained was of UDCA crystals. The crystalline peaks gradually decreased in intensity at a temperature of 150 degrees C When the temperature was up to 160 degrees C, the identical crystalline peaks of UDCA crystals completely disappeared. It was concluded that the anomalous endothermic peak at 155 degrees C-157 degrees C was the peak due to the dissolution of UDCA crystals in the surrounding melted urea.


Assuntos
Ureia/química , Ácido Ursodesoxicólico/química , Varredura Diferencial de Calorimetria , Cristalografia por Raios X , Pós , Termodinâmica
19.
Biosci Biotechnol Biochem ; 65(2): 438-41, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11302184

RESUMO

A thermostable beta-glucosidase from Thermus sp. Z-1 that not only hydrolyzes beta-glucosides but also beta-galactosides was shown to efficiently produce oligosaccharides during hydrolysis of lactose. The yield of oligosaccharides was more than 40% for 0.88 M lactose solution at 70 degrees C at pH 7.0. The major product was a trisaccharide, 3'-galactosyllactose, formed by a galactosyltransfer reaction.


Assuntos
Lactose/metabolismo , Oligossacarídeos/biossíntese , Thermus/enzimologia , beta-Glucosidase/metabolismo , Estabilidade Enzimática , Escherichia coli/genética , Temperatura Alta , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Ressonância Magnética , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , Thermus/genética , Trissacarídeos/biossíntese , beta-Glucosidase/genética , beta-Glucosidase/isolamento & purificação
20.
J Colloid Interface Sci ; 216(2): 276-284, 1999 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10421735

RESUMO

The objective of this study was to reduce the crystallinity of ursodeoxycholic acid (UDCA) by solid dispersion with controlled pore glass (CPG). To evaluate the effect of pore diameter and pore volume of CPG on the crystalline properties of UDCA, we used powder X-ray diffractometry (PXRD) and differential scanning calorimetry (DSC). PXRD patterns and the DSC data indicated the presence of UDCA in a crystalline state in the physical mixtures. It was found that amorphous UDCA could be formed via solid dispersion with CPG obtained by a solvent method. The DSC thermograms of solid dispersions showed that there were two states of UDCA, amorphous and crystalline. The amount of crystalline fraction in the solid dispersions depended on the pore size, pore volume, and the specific surface area of CPG. When UDCA was mixed with different pore diameters of CPG, it was found that UDCA molecules preferentially interacted with pores of smaller size. Copyright 1999 Academic Press.

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