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1.
Regul Toxicol Pharmacol ; 122: 104885, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33617940

RESUMO

Nanotechnology and more particularly nanotechnology-based products and materials have provided a huge potential for novel solutions to many of the current challenges society is facing. However, nanotechnology is also an area of product innovation that is sometimes developing faster than regulatory frameworks. This is due to the high complexity of some nanomaterials, the lack of a globally harmonised regulatory definition and the different scopes of regulation at a global level. Research organisations and regulatory bodies have spent many efforts in the last two decades to cope with these challenges. Although there has been a significant advancement related to analytical approaches for labelling purposes as well as to the development of suitable test guidelines for nanomaterials and their safety assessment, there is a still a need for greater global collaboration and consensus in the regulatory field. Furthermore, with growing societal concerns on plastic litter and tiny debris produced by degradation of littered plastic objects, the impact of micro- and nanoplastics on humans and the environment is an emerging issue. Despite increasing research and initial regulatory discussions on micro- and nanoplastics, there are still knowledge gaps and thus an urgent need for action. As nanoplastics can be classified as a specific type of incidental nanomaterials, current and future scientific investigations should take into account the existing profound knowledge on nanotechnology/nanomaterials when discussing issues around nanoplastics. This review was conceived at the 2019 Global Summit on Regulatory Sciences that took place in Stresa, Italy, on 24-26 September 2019 (GSRS 2019) and which was co-organised by the Global Coalition for Regulatory Science Research (GCRSR) and the European Commission's (EC) Joint Research Centre (JRC). The GCRSR consists of regulatory bodies from various countries around the globe including EU bodies. The 2019 Global Summit provided an excellent platform to exchange the latest information on activities carried out by regulatory bodies with a focus on the application of nanotechnology in the agriculture/food sector, on nanoplastics and on nanomedicines, including taking stock and promoting further collaboration. Recently, the topic of micro- and nanoplastics has become a new focus of the GCRSR. Besides discussing the challenges and needs, some future directions on how new tools and methodologies can improve the regulatory science were elaborated by summarising a significant portion of discussions during the summit. It has been revealed that there are still some uncertainties and knowledge gaps with regard to physicochemical properties, environmental behaviour and toxicological effects, especially as testing described in the dossiers is often done early in the product development process, and the material in the final product may behave differently. The harmonisation of methodologies for quantification and risk assessment of nanomaterials and micro/nanoplastics, the documentation of regulatory science studies and the need for sharing databases were highlighted as important aspects to look at.


Assuntos
Internacionalidade , Microplásticos/química , Microplásticos/normas , Nanoestruturas/química , Nanoestruturas/normas , Exposição Ambiental/efeitos adversos , Saúde Ambiental/normas , Microplásticos/efeitos adversos , Nanoestruturas/efeitos adversos , Padrões de Referência
2.
Genes Cells ; 24(12): 827-835, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31637814

RESUMO

Antisense oligonucleotide (ASO) has the potential to induce off-target effects due to complementary binding between the ASO and unintended RNA with a sequence similar to the target RNA. Conventional animal studies cannot be used to assess toxicity induced by off-target effects because of differences in the genome sequence between humans and other animals. Consequently, the assessment of off-target effects with in silico analysis using a human RNA database and/or in vitro expression analysis using human cells has been proposed. Our previous study showed that the number of complementary regions of ASOs with mismatches in the human RNA sequences increases dramatically as the number of tolerated mismatches increases. However, to what extent the expression of genes with mismatches is affected by off-target effects at the cellular level is not clear. In this study, we evaluated off-target effects of gapmer ASOs, which cleave the target RNA in an RNase H-dependent manner, by introducing the ASO into human cells and performing microarray analysis. Our data indicate that gapmer ASOs induce off-target effects depending on the degree of complementarity between the ASO and off-target candidate genes. Based on our results, we also propose a scheme for the assessment of off-target effects of gapmer ASOs.


Assuntos
Pareamento Incorreto de Bases , Pareamento de Bases , Oligonucleotídeos Antissenso/química , Algoritmos , Linhagem Celular Tumoral , Humanos , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/metabolismo , RNA/química , RNA/genética , RNA/metabolismo , Análise de Sequência de RNA/métodos
3.
Chem Pharm Bull (Tokyo) ; 68(10): 1008-1012, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32779580

RESUMO

The purpose of this study was to elucidate the effect of high-temperature storage on the stability of ranitidine, specifically with respect to the potential formation of N-nitrosodimethylamine (NDMA), which is classified as a probable human carcinogen. Commercially available ranitidine reagent powders and formulations were stored under various conditions, and subjected to LC-MS/MS analysis. When ranitidine tablets from two different brands (designated as tablet A and tablet B) were stored under accelerated condition (40 °C with 75% relative humidity), following the drug stability guidelines issued by the International Conference on Harmonisation (ICH-Q1A), for up to 8 weeks, the amount of NDMA in them substantially increased from 0.19 to 116 ppm and from 2.89 to 18 ppm, respectively. The formation of NDMA that exceeded the acceptable daily intake limit (0.32 ppm) at the temperature used under accelerated storage conditions clearly highlights the risk of NDMA formation in ranitidine formulations when extrapolated to storage under ambient conditions. A forced-degradation study under the stress condition (60 °C for 1 week) strongly suggested that environmental factors such as moisture and oxygen are involved in the formation of NDMA in ranitidine formulations. Storage of ranitidine tablets and reagent powders at the high temperatures also increased the amount of nitrite, which is considered one of the factors influencing NDMA formation. These data indicate the necessity of controlling/monitoring stability-related factors, in addition to controlling impurities during the manufacturing process, in order to mitigate nitrosamine-related health risks of certain pharmaceuticals.


Assuntos
Dimetilnitrosamina/química , Ranitidina/química , Cromatografia Líquida de Alta Pressão , Composição de Medicamentos , Estabilidade de Medicamentos , Humanos , Nitritos/química , Nitrosaminas/química , Pós/química , Ranitidina/farmacologia , Comprimidos/química , Espectrometria de Massas em Tandem , Temperatura
4.
Biol Pharm Bull ; 42(4): 547-551, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30726781

RESUMO

Valsartan products, commonly used to treat high blood pressure and heart failure, have been recalled in many countries due to the presence of an impurity, N-nitrosodimethylamine (NDMA), in the recalled products. We present and evaluate a GC-MS-based analytical method for the determination of NDMA levels and attempt an investigation of NDMA concentrations in valsartan drug substances and associated products. The limit of detection and limit of quantification for the method were estimated to be 0.1 and 0.5 µg/g, respectively, when testing a 0.5-g sample. A good trueness (99%) with a small relative standard deviation (1.9%) was obtained for a valsartan product spiked with NDMA at a concentration of 1.0 µg/g. Additionally, a valsartan drug substance and the associated product, which were previously determined to have NDMA contamination, were analyzed by the method. The NDMA content by our method was very close to previously determined values. Finally, six samples, including valsartan drug substances and associated, commercially available products in Japan, all of which were derived from the company implicated in the NDMA contamination, were analyzed by our method, revealing that none of these samples contained detectable concentrations of NDMA. Overall, the data indicate that the present method is reliable and useful for determination of NDMA in valsartan drug substances and associated products.


Assuntos
Anti-Hipertensivos/análise , Dimetilnitrosamina/análise , Contaminação de Medicamentos/prevenção & controle , Valsartana/análise , Métodos Analíticos de Preparação de Amostras , Anti-Hipertensivos/normas , Cromatografia Gasosa-Espectrometria de Massas , Japão , Limite de Detecção , Comprimidos , Valsartana/normas
5.
AAPS PharmSciTech ; 20(2): 70, 2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30631974

RESUMO

The characterization of nanocrystalline active ingredients in multicomponent formulations for the design and manufacture of products with increased bioavailability is often challenging. The purpose of this study is to develop an atomic force microscopy (AFM) imaging method for the detailed morphological characterization of nanocrystalline active ingredients in multicomponent oral formulations. The AFM images of aprepitant and sirolimus nanoparticles in aqueous suspension show that their sizes are comparable with those measured using dynamic light scattering (DLS) analysis. The method also provides information on a wide-sized range of particles, including small particles that can often only be detected by DLS when larger particles are removed by additional filtration steps. An expected advantage of the AFM method is the ability to obtain a detailed information on particle morphology and stiffness, which allows the active pharmaceutical ingredient and excipient (titanium dioxide) particles to be distinguished. Selective imaging of particles can also be achieved by varying the surface properties of the AFM solid substrate, which allows to control the interactions between the substrate and the active pharmaceutical ingredient and excipient particles. AFM analysis in combination with other methods (e.g., DLS), should facilitate the rational development of formulations based on nanoparticles.


Assuntos
Aprepitanto/química , Microscopia de Força Atômica/métodos , Nanopartículas/química , Sirolimo/química , Administração Oral , Composição de Medicamentos , Excipientes , Luz , Tamanho da Partícula , Espalhamento de Radiação , Propriedades de Superfície
6.
Regul Toxicol Pharmacol ; 98: 115-128, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30048704

RESUMO

Emerging technologies are playing a major role in the generation of new approaches to assess the safety of both foods and drugs. However, the integration of emerging technologies in the regulatory decision-making process requires rigorous assessment and consensus amongst international partners and research communities. To that end, the Global Coalition for Regulatory Science Research (GCRSR) in partnership with the Brazilian Health Surveillance Agency (ANVISA) hosted the seventh Global Summit on Regulatory Science (GSRS17) in Brasilia, Brazil on September 18-20, 2017 to discuss the role of new approaches in regulatory science with a specific emphasis on applications in food and medical product safety. The global regulatory landscape concerning the application of new technologies was assessed in several countries worldwide. Challenges and issues were discussed in the context of developing an international consensus for objective criteria in the development, application and review of emerging technologies. The need for advanced approaches to allow for faster, less expensive and more predictive methodologies was elaborated. In addition, the strengths and weaknesses of each new approach was discussed. And finally, the need for standards and reproducible approaches was reviewed to enhance the application of the emerging technologies to improve food and drug safety. The overarching goal of GSRS17 was to provide a venue where regulators and researchers meet to develop collaborations addressing the most pressing scientific challenges and facilitate the adoption of novel technical innovations to advance the field of regulatory science.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Inocuidade dos Alimentos , Animais , Avaliação Pré-Clínica de Medicamentos , Humanos , Legislação de Medicamentos , Legislação sobre Alimentos , Medição de Risco , Testes de Toxicidade
7.
Chem Pharm Bull (Tokyo) ; 65(3): 218-228, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28250343

RESUMO

We applied the Quality by Design (QbD) approach to the development of poly(lactic-co-glycolic acid) (PLGA) nanoparticle formulations encapsulating triamcinolone acetonide, and the critical process parameters (CPPs) were identified to clarify the correlations between critical quality attributes and CPPs. Quality risk management was performed by using an Ishikawa diagram and experiments with a fractional factorial design (ANOVA). The CPPs for particle size were PLGA concentration and rotation speed, and the CPP for relative drug loading efficiency was the poor solvent to good solvent volume ratio. By assessing the mutually related factors in the form of ratios, many factors could be efficiently considered in the risk assessment. We found a two-factor interaction between rotation speed and rate of addition of good solvent by using a fractional factorial design with resolution V. The system was then extended by using a central composite design, and the results obtained were visualized by using the response surface method to construct a design space. Our research represents a case study of the application of the QbD approach to pharmaceutical development, including formulation screening, by taking actual production factors into consideration. Our findings support the feasibility of using a similar approach to nanoparticle formulations under development. We could establish an efficient method of analyzing the CPPs of PLGA nanoparticles by using a QbD approach.


Assuntos
Desenho de Fármacos , Interações Hidrofóbicas e Hidrofílicas , Ácido Láctico/química , Nanopartículas/química , Ácido Poliglicólico/química , Triancinolona Acetonida/química , Química Farmacêutica , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Propriedades de Superfície
8.
Langmuir ; 32(24): 6074-82, 2016 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-27232007

RESUMO

Mechanical rigidity of the liposome membrane is often defined by the membrane bending modulus and is one of the determinants of liposome stability, but the quantitative experimental data are still limited to a few kinds of liposomes. Here, we used atomic force microscopy to investigate the membrane bending moduli of liposomes by immobilizing them on bovine serum albumin-coated glass in aqueous medium. The following lipids were used for liposome preparation: egg yolk phosphatidylcholine, dioleoylphosphatidylcholine, hydrogenated soybean phosphatidylcholine, dipalmitoylphosphatidylcholine, 1,2-dioleoyl-3-trimethylammonium-propane, cholesterol, and N-(carbonylmethoxypoly(ethylene glycol) 2000)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine. By using liposomes of various compositions, we showed that the thermodynamic phase state of the membrane rather than the electric potential or liposome surface modification with poly(ethylene glycol) is the predominant determinant of the bending modulus, which decreased in the following order: solid ordered > liquid ordered > liquid disordered. By using the generalized polarization value of the Laurdan fluorescent probe, we investigated membrane rigidity in terms of membrane fluidity. Atomic force microscopic analysis was superior to the Laurdan method, especially in evaluating the membrane rigidity of liposomes containing hydrogenated soybean phosphatidylcholine and cholesterol. Positively charged liposomes with a large bending modulus were taken up by cells more efficiently than those with a small bending modulus. These findings offer a quantitative method of analyzing the membrane rigidity of nanosized liposomes with different lipid compositions and will contribute to the control of liposome stability and cellular uptake efficiency of liposomal formulations intended for clinical use.


Assuntos
Lipídeos/química , Lipossomos/química , Microscopia de Força Atômica , Polietilenoglicóis/química , Composição de Medicamentos
9.
Biochim Biophys Acta ; 1840(3): 1171-80, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24361607

RESUMO

BACKGROUND: Amorphous silica particles with the primary dimensions of a few tens of nm, have been widely applied as additives in various fields including medicine and food. Especially, they have been widely applied in powders for making tablets and to coat tablets. However, their behavior and biological effects in the gastrointestinal tracts associated with oral administration remains unknown. METHODS: Amorphous silica particles with diameters of 50, 100, and 200nm were incubated in the fasted-state and fed-state simulated gastric and intestinal fluids. The sizes, intracellular transport into Caco-2 cells (model cells for intestinal absorption), the Caco-2 monolayer membrane permeability, and the cytotoxicity against Caco-2 cells were then evaluated for the silica particles. RESULTS: Silica particles agglomerated in fed-state simultaneous intestinal fluids. The agglomeration and increased particles size inhibited the particles' absorption into the Caco-2 cells or particles' transport through the Caco-2 cells. The in vitro cytotoxicity of silica particles was not observed when the average size was larger than 100nm, independent of the fluid and the concentration. CONCLUSION: Our study indicated the effect of diet on the agglomeration of silica particles. The sizes of silica particles affected the particles' absorption into or transport through the Caco-2 cells, and cytotoxicity in vitro, depending on the various biological fluids. GENERAL SIGNIFICANCE: The findings obtained from our study may offer valuable information to evaluate the behavior of silica particles in the gastrointestinal tracts or safety of medicines or foods containing these materials as additives.


Assuntos
Absorção Intestinal , Dióxido de Silício/toxicidade , Líquidos Corporais , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Humanos , Tamanho da Partícula , Dióxido de Silício/química , Dióxido de Silício/farmacocinética
10.
Mol Pharm ; 12(9): 3175-83, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26194248

RESUMO

We previously elucidated that ATP-binding cassette subfamily B member 1 (ABCB1) mediates the efflux of doxorubicin-conjugated block copolymers from HeLa cells. Here, we investigated the role of ABCB1 in the in vivo behavior of a doxorubicin-conjugated polymer in Mdr1a/1b(-/-) mice. The area under the curve for intravenously administered polymer in Mdr1a/1b(-/-) mice was 2.2-fold greater than that in wild-type mice. The polymer was mostly distributed in the liver followed by spleen and less so in the brain, heart, kidney, and lung. The amount of polymer excreted in the urine was significantly decreased in Mdr1a/1b(-/-) mice. The amounts of polymers excreted in the feces were similar in both groups despite the higher systemic exposure in Mdr1a/1b(-/-) mice. Confocal microscopy images showed polymer localized in CD68(+) macrophages in the liver. These results show that knockout of ABCB1 prolonged systemic exposure of the doxorubicin-conjugated polymer in mice. Our results suggest that ABCB1 mediated the excretion of doxorubicin-conjugated polymer in urine and feces. Our results provide valuable information about the behavior of block copolymers in vivo, which is important for evaluating the pharmacokinetics of active substances conjugated to block copolymers or the accumulation of block copolymers in vivo.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/fisiologia , Transportadores de Cassetes de Ligação de ATP/fisiologia , Doxorrubicina/farmacocinética , Polímeros/química , Animais , Antibióticos Antineoplásicos/farmacocinética , Feminino , Camundongos , Camundongos Knockout , Distribuição Tecidual , Membro 4 da Subfamília B de Transportadores de Cassetes de Ligação de ATP
11.
Chem Pharm Bull (Tokyo) ; 63(9): 663-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26329859

RESUMO

The aim of this study was to evaluate pharmaceuticals using a near-infrared chemical imaging (NIR-CI) technique for visualizing the distribution of ingredients in solid dosage forms of commercially available clarithromycin tablets. The cross section of a tablet was measured using the NIR-CI system for evaluating the distribution of ingredients in the tablet. The chemical images were generated by performing multivariate analysis methods: principal component analysis (PCA) and partial least squares (PLS) with normalized near-infrared (NIR) spectral data. We gained spectral and distributional information related to clarithromycin, cornstarch, and magnesium stearate by using PCA analysis. On the basis of this information, the distribution images of these ingredients were generated using PLS analysis. The results of PCA analysis enabled us to analyze individual components by using PLS even if sufficient information on the products was not available. However, some ingredients such as binder could not be detected using NIR-CI, because their particle sizes were smaller than the pixel size (approximately 25×25×50 µm) and they were present in low concentrations. The combined analysis using both PCA and PLS with NIR-CI was useful to analyze the distribution of ingredients in a commercially available pharmaceutical even when sufficient information on the product is not available.


Assuntos
Claritromicina/análise , Análise dos Mínimos Quadrados , Análise de Componente Principal , Espectroscopia de Luz Próxima ao Infravermelho , Comprimidos/análise
12.
Drug Dev Ind Pharm ; 41(8): 1376-86, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25170659

RESUMO

Establishing appropriate drug release testing methods of liposomal products for assuring quality and performance requires the determination of factors affecting in vitro drug release. In this study, we investigated the effects of test conditions (human plasma lot, pH/salt concentration in the test media, dilution factor, temperature, ultrasound irradiation, etc.), and liposomal preparation conditions (pH/concentration of ammonium sulfate solution), on doxorubicin (DXR) release from PEGylated liposomal DXR. Higher temperature and lower pH significantly increased DXR release. The evaluation of DXR solubility indicated that the high DXR release induced by low pH may be attributed to the high solubility of DXR at low pH. Ultrasound irradiation induced rapid DXR release in an amplitude-dependent manner. The salt concentration in the test solution, human plasma lot, and dilution factor had a limited impact on DXR-release. Variations in the ammonium sulfate concentration used in solutions for the formation/hydration of liposomes significantly affected DXR release behavior, whereas differences in pH did not. In addition, heating condition in phosphate-buffered saline at lower pH (<6.5) exhibited higher discriminative ability for the release profiles from various liposomes with different concentrations of ammonium sulfate than did ultrasound irradiation. These results are expected to be helpful in the process of establishing appropriate drug release testing methods for PEGylated liposomal DXR.


Assuntos
Doxorrubicina/análogos & derivados , Polietilenoglicóis/farmacocinética , Antibióticos Antineoplásicos/sangue , Antibióticos Antineoplásicos/farmacocinética , Doxorrubicina/sangue , Doxorrubicina/farmacocinética , Humanos
13.
Mol Pharm ; 11(2): 560-7, 2014 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-24383572

RESUMO

We have previously reported the intracellular trafficking mechanism of liposomal phospholipids. In the present study, we investigated the effects of liposomal phospholipids on the intracellular trafficking of doxorubicin (DXR). In DXR-encapsulated liposomes, polyethylene glycol (PEG)-modified phospholipids have been widely used as one of the liposomal lipids. First, we investigated the intracellular trafficking mechanism of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy-PEG2000] (PEG2000-DSPE), and demonstrated that the intracellular trafficking pathways of phospholipids changed by PEG modification. Then, we evaluated the effects of liposomal DXR on the intracellular trafficking of liposomal phospholipids. Under the phosphatidylinositol transfer protein (PITP)-suppressing condition by siRNA treatment, the intracellular amounts of DSPC derived from DXR-encapsulated liposomes were larger than that from nonencapsulated liposomes. Moreover, following the effects of liposomal phospholipids on the intracellular amounts of DXR, the intracellular amounts of DXR were increased under the PITP-suppressing condition in DXR-encapsulated liposomes. We showed that intracellular DXR was associated with the complex of PITP and DSPC, and the extracellular efflux of DXR was enhanced by complex formation with PITP and DSPC.


Assuntos
Doxorrubicina/metabolismo , Sistemas de Liberação de Medicamentos , Lipossomos/química , Modelos Biológicos , Fosfolipídeos/química , Western Blotting , Cápsulas/química , Células HeLa , Humanos , Microscopia Confocal
14.
Biol Pharm Bull ; 37(1): 164-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24389491

RESUMO

Human orosomucoid (ORM) is a major acute-phase plasma protein, encoded by 2 highly homologous genes, ORM1 and ORM2. Human ORM induction is assumed to be regulated by each proximal promoter region, where putative glucocorticoid responsive elements and CCAAT/enhancer binding protein (C/EBP)ß binding sites are located. However, the details of the differential regulation of these genes remain unknown. To explore this, we assessed the role of the distal promoter region of each ORM in HeLa cells. Luciferase-reporter activities of full constructs, containing approximately 1.1 kbp (FULL), and those of deletion constructs, containing up to 188 bp region (DEL) upstream of the transcription start sites of ORM1 and ORM2 were compared under both basal and inducer-treated conditions. For ORM1 and ORM2 DEL constructs, significantly increased activities after dexamethasone (DEX) treatments (alone and combined with interleukin (IL)-1ß) were observed. Significantly higher FULL construct activities than DEL construct activities were observed for ORM1 after IL-1ß treatment, while those for ORM2 were significantly lower at basal level and after DEX treatments. Upon C/EBPß overexpression, FULL construct activities were significantly higher than those of DEL constructs at basal level and after IL-1ß treatment for ORM1, and at basal level and after inducer-treatments for ORM2. Higher transcription-induction activity in the distal promoter region was evident for ORM1 in the absence of C/EBPß overexpression, and for ORM2 under C/EBPß overexpression conditions. These findings suggest that the ORM distal promoter region differentially regulates expression of ORM genes at basal level and in acute phase responses.


Assuntos
Reação de Fase Aguda/genética , Expressão Gênica , Orosomucoide/genética , Regiões Promotoras Genéticas , Ativação Transcricional , Proteína beta Intensificadora de Ligação a CCAAT/genética , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Dexametasona/farmacologia , Glucocorticoides/farmacologia , Células HeLa , Humanos , Interleucina-1beta/farmacologia , Orosomucoide/metabolismo
15.
AAPS PharmSciTech ; 15(5): 1181-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24879291

RESUMO

The objective of this study was to determine how different techniques used during the freezing step of lyophilization affect morphology of the dried protein solids. Aqueous solutions containing recombinant human albumin, trehalose, and sodium phosphate buffer were dried after their freezing by shelf-ramp cooling, immersion in liquid nitrogen, or controlled ice nucleation. Some shelf-frozen solutions were heat treated (annealed) before the vacuum drying. We used three-dimensional (3D) X-ray micro-computed tomography (micro-CT) and scanning electron microscopy (SEM) to study the morphology of solids. The X-ray micro-CT images of the lyophilized microporous solids showed traces of varied size and structure ice crystals that were comparable to corresponding SEM images. A post-freeze heat treatment and a controlled nucleation both induced larger ice crystal ghosts in the solids. The variations in the structure of walls surrounding ice crystals, formed by the different freezing procedures, should affect the water vapor transition during the primary and secondary drying. Some solids also showed higher-density layer in the upper surface. Overall, the simple sample preparation procedures and the ample morphological information make the X-ray micro-CT appropriate for analyzing lyophilized pharmaceuticals.


Assuntos
Proteínas/química , Análise Diferencial Térmica , Liofilização , Congelamento , Imageamento Tridimensional , Microscopia Eletrônica de Varredura , Albumina Sérica/química , Soluções , Tomografia Computadorizada por Raios X , Água/análise
16.
Cancer Sci ; 104(11): 1492-8, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23992566

RESUMO

Manipulation of protein stability with small molecules has a great potential for both basic research and clinical therapy. Recently, we have developed a series of hybrid small molecules named SNIPER (Specific and Non-genetic IAP-dependent Protein ERaser) that induces degradation of target proteins via ubiquitin-proteasome system. Here we report the activities of SNIPER(ER) that targets estrogen receptor alpha (ERα) for degradation. SNIPER(ER) induced degradation of ERα and inhibited estrogen-dependent expression of pS2 gene in an estrogen-dependent breast cancer cell line MCF-7. A proteasome inhibitor MG132 and siRNA-mediated downregulation of cIAP1 abrogated the SNIPER(ER)-induced ERα degradation, suggesting that the ERα is degraded by proteasome subsequent to cIAP1-mediated ubiquitylation. Intriguingly, after the ERα degradation, the SNIPER(ER)-treated MCF-7 cells undergo rapid cell death. Detailed analysis indicated that SNIPER(ER) caused necrotic cell death accompanied by a release of HMGB1, a marker of necrosis, from the cells. Following the ERα degradation, reactive oxygen species (ROS) was produced in the SNIPER(ER)-treated MCF-7 cells, and an anti-oxidant N-acetylcysteine inhibited the necrotic cell death. These results indicate that SNIPER(ER) induces ERα degradation, ROS production and necrotic cell death, implying a therapeutic potential of SNIPER(ER) as a lead for the treatment of ERα-positive breast cancers.


Assuntos
Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/tratamento farmacológico , Receptor alfa de Estrogênio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Desenho de Fármacos , Feminino , Humanos , Células MCF-7 , Necrose , Complexo de Endopeptidases do Proteassoma/metabolismo , Estabilidade Proteica , Proteólise/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
17.
AAPS PharmSciTech ; 14(2): 811-7, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23609521

RESUMO

Liposomes incorporating polyethylene glycol (PEG)-conjugated lipids (PEGylated liposomes) have attracted attention as drug delivery carriers because they show good in vivo stability. The lipid component of PEGylated liposomal formulations needs to be quantified for quality control. In this study, a simple reversed-phase high-performance liquid chromatography (HPLC) method with an evaporative light-scattering detector (ELSD) was established for simultaneous determination of hydrogenated soy phosphatidylcholine, cholesterol, PEG-conjugated lipid, and hydrolysis products of phospholipid in PEGylated liposomal formulations. These lipids were separated using a C18 column with a gradient mobile phase consisting of ammonium acetate buffer and ammonium acetate in methanol at a flow rate of 1.0 ml/min. This method provided sufficient repeatability, linearity, and recovery rate for all lipids. However, the linearity and recovery rates of cholesterol achieved using a ultraviolet (UV) detector were better than those achieved using an ELSD. This validated method can be applied to assess the composition change during the preparation process of liposomes and to quantify lipid components and hydrolysis products contained in a commercially available liposomal formulation DOXIL®. Taken together, this reversed-phase HPLC-UV/ELSD method may be useful for the rapid or routine analysis of liposomal lipid components in process development and quality control.


Assuntos
Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Luz , Lipídeos/análise , Polietilenoglicóis/análise , Espalhamento de Radiação , Tecnologia Farmacêutica/métodos , Acetatos/química , Soluções Tampão , Química Farmacêutica , Concentração de Íons de Hidrogênio , Limite de Detecção , Modelos Lineares , Lipólise , Lipossomos , Metanol/química , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , Temperatura , Raios Ultravioleta
18.
J Clin Biochem Nutr ; 52(2): 133-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23526113

RESUMO

Alzheimer's disease (AD) is the most common cause of neurodegenerative dementia among elderly patients. A biomarker for the disease could make diagnosis easier and more accurate, and accelerate drug discovery. In this study, NMR-based metabolomics analysis in conjunction with multivariate statistics was applied to examine changes in urinary metabolites in transgenic AD mice expressing mutant tau and ß-amyloid precursor protein. These mice showed significant changes in urinary metabolites throughout the progress of the disease. Levels of 3-hydroxykynurenine, homogentisate and allantoin were significantly higher compared to control mice in 4 months (prior to onset of AD symptoms) and reverted to control values by 10 months of age (early/middle stage of AD), which highlights the relevance of oxidative stress to this neurodegenerative disorder even prior the onset of dementia. The level of these changed metabolites at very early period may provide an indication of disease risk at asymptomatic stage.

19.
Artigo em Japonês | MEDLINE | ID: mdl-24340671

RESUMO

A training course for analysis of B vitamins in syrup products was undertaken at the National Agency of Drug and Food Control at Jakarta as part of the project to deliver safe drugs to people in Indonesia by Japan International Cooperation Agency. Analytical methods have been developed for quantitative determination of B vitamins by ion-pair high-performance liquid chromatography using 1-hexanesulfonic acid sodium salt. Measurements were performed for two syrup products removed from a drug store in Jakarta to determine the amount of each vitamin B. The measured values of riboflavin 5'-phosphate sodium, nicotinamide and pyridoxine hydrochloride were almost the same with those of nominal content for both products. While the measured values of thiamine hydrochloride, pantothenol and cyanocobalamin were approximately twice the amount of nominal contents.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Complexo Vitamínico B/análise , Ácidos Alcanossulfônicos , Formas de Dosagem , Indonésia
20.
Immunogenetics ; 64(12): 869-77, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22903236

RESUMO

Fcγ receptor IIa (FcγRIIa) plays an important role in antibody-dependent cellular cytotoxicity and inflammation. Changes in FcγRIIa expression levels or activity caused by genetic polymorphisms in FCGR2A, the gene encoding FcγRIIa, may lead to differences in disease progression as well as efficacy of antibody therapeutics between individuals. In this study, we sequenced the 5'-flanking region along with all exons and their flanking regions of FCGR2A from 111 Japanese subjects. Forty-eight genetic variations were found including 12 novel ones. Beside the well-known functional 497A > G (H166R) polymorphism, we detected 818T > C (L273P) at 0.005 frequency. Since the functional significance of this polymorphism has not been revealed, we next assessed the functions of the L273P substitution by expressing wild-type and the variant proteins in human Jurkat cells. The L273P variant protein showed similar cell surface expression and IgG-binding properties as the wild-type, but it exhibited a stronger signal transduction activity based on the approximately 2-fold enhancement of tyrosine phosphorylation of FcγRIIa itself. The current results suggest that L273P could have functional significance in the antibody-dependent clinical responses through FcγRIIa.


Assuntos
Povo Asiático/genética , Polimorfismo Genético , Receptores de IgG/genética , Linhagem Celular , Éxons , Humanos , Células Jurkat , Leucina/genética , Fosforilação , Prolina/genética , Transdução de Sinais/genética , Tirosina/metabolismo
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