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1.
J Orthod ; 48(4): 343-351, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34227411

RESUMEN

OBJECTIVE: To compare two methods of providing information about the Bone Anchored Maxillary Protraction (BAMP) trial: standard printed information and multimedia websites, for their quality and ease of understanding, and impact on decision-making. DESIGN: Randomised controlled trial. SETTING: Orthodontic outpatient clinic in the UK. METHODS: Participants were 109 adolescents (aged 11-14 years) attending for orthodontic treatment. While awaiting treatment they were asked to imagine being recruited to the BAMP clinical trial. They were individually randomised to receive the printed or the multimedia website information (comprising text, animations and 'talking head' videos). After reading or viewing the information, they completed a 9-item Likert scale Decision-Making Questionnaire (DMQ) (score range 0-36) plus three free-text questions on their evaluation of the information. RESULTS: A total of 104 participants completed the questionnaire. Mean total DMQ scores were higher (more positive) in the website group (28.1 vs. 27.0), although the difference was small and not statistically significant (P = 0.20). Analysis of individual questionnaire items showed two statistically significant differences: the website information had higher ratings on 'easy to understand' (Z = 3.03; P = 0.003) and 'confidence in decision-making' (Z = 2.00; P = 0.044). On the three free-text questions, more positive and fewer negative comments were made about the websites than the printed information. CONCLUSION: In this hypothetical trial setting, adolescent patients found that trial information conveyed on a multimedia website was easier to understand and made them more confident in their decision about trial participation. Their subjective evaluations of the website were also more positive and less negative than about the printed information. Multimedia information has the potential to increase the quality of engagement and information exchange when seeking consent for research.


Asunto(s)
Multimedia , Ortodoncia , Adolescente , Humanos , Encuestas y Cuestionarios
2.
Int J Pharm ; 453(2): 351-7, 2013 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-23751342

RESUMEN

Biosimilar pharmaceuticals are complex biological molecules that have similar physicochemical properties to the originator therapeutic protein. They are produced by complex multi-stage processes and are not truly equivalent. Therefore, for a biosimilar to be approved for market it is important to demonstrate that the biological product is highly similar to a reference product. This includes its primary and higher order structures and its aggregation behaviour. Representative lots of both the proposed biosimilar and the reference product are analysed to understand the lot-to-lot variability of both drug substances in the manufacturing processes. Whilst it is not easy to characterise every variation of a protein structure at present additional analytical technologies need to be utilised to ensure the safety and efficacy of any potential biosimilar product. We have explored the use of Taylor dispersion analysis (TDA) to analyse such batch to batch variations in the model protein, bovine serum albumin (BSA) and compared the results to that obtained by conventional dynamic light scattering analysis (DLS). Inter and intra batch differences were evident in all grades of BSA analysed. However, the reproducibility of the TDA measurements, enabled the stability and reversibility of BSA aggregates to be more readily monitored. This demonstrates that Taylor dispersion analysis is a very sensitive technique to study higher order protein states and aggregation. The results, here, also indicate a correlation between protein purity and the physical behaviour of the samples after heat shocking. Here, the protein with the highest quoted purity resulted in a reduced increase in the measured hydrodynamic radius after heat stressing, indicating that less unfolding/aggregation had occurred. Whilst DLS was also able to observe the presence of aggregates, its bias towards larger aggregates indicated a much larger increase in hydrodynamic radii and is less sensitive to small changes in hydrodynamic radii. TDA was also able to identify low levels of larger aggregates that were not observed by DLS. Therefore, given the potential for immunogenicity effects that may result from such aggregates it is suggested that TDA may be suitable in the evaluating detailed batch to batch variability and process induced physical changes of biopharmaceuticals and biosimilars.


Asunto(s)
Técnicas de Química Analítica/métodos , Proteínas/química , Luz , Dispersión de Radiación , Albúmina Sérica Bovina/química
3.
Int J Pharm ; 434(1-2): 133-9, 2012 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-22626886

RESUMEN

For efficient and effective drug development it is desirable to acquire a deep understanding of the dissolution behaviour of potential candidate drugs and their physical forms as early as possible and with the limited amounts of material that are available at that time. Using 3-10mg sample quantities, the ability of a UV imaging system is investigated to provide deep mechanistic insight into the intrinsic dissolution profiling of a range of compounds and physical forms assessed under flow conditions. Physical forms of indomethacin, theophylline and ibuprofen were compressed and their solid-state form confirmed before and after compression with X-ray methods and/or Raman spectroscopy. Intrinsic dissolution rates (IDRs) were determined using the compact's UV-imaging profile. The ratio in the IDRs for theophylline anhydrate over hydrate was 2.1 and the ratio for the alpha form of indomethacin over the gamma form was approximately 1.7. The discriminatory power of the novel UV area visualisation approach was shown to be high in that process-induced solid-state dissolution differences post-micronisation could be detected. Additionally, the scale-down system was able to visualise a previously observed increase in ibuprofen IDR with an increase in concentration of sodium dodecyl sulphate. The mechanistic dissolution insights from the visualisation approach are evident.


Asunto(s)
Diseño de Fármacos , Ibuprofeno/química , Indometacina/química , Teofilina/química , Química Farmacéutica , Dodecil Sulfato de Sodio/química , Solubilidad , Espectrometría Raman , Tecnología Farmacéutica/métodos , Rayos Ultravioleta , Difracción de Rayos X
4.
Int J Pharm ; 416(1): 394-7, 2011 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-21745555

RESUMEN

The growing number of Biosimilars now being approved for development lends the need to develop new analytical techniques for rapid, cost effective analysis of these high value biotherapeutics. The presence of aggregates in biopharmaceutical products is undesirable for many reasons. A major concern is the potential immunogeneic response that aggregates can induce on administration. The detection of low levels of aggregated proteins in solution may only be determined by a limited number of techniques, many of which require in-depth method development, multi-stage sample preparation and lengthy time of analysis. We explore the use of a novel analytical instrument using UV area imaging and Taylor dispersion analysis (TDA) to determine the hydrodynamic radius of BSA in an aggregated state and monitor it with time. Protein aggregation and its reversibility over time has been measured for a number of BSA samples (stressed and unstressed) by TDA with the results obtained being compared to those obtained from dynamic light scattering (DLS) and microcalorimetry. Correlations between the techniques for investigating protein aggregation behaviour were explored. The reproducibility of TDA measurements enabled the stability and reversibility of BSA aggregates to be more readily monitored than by using the other techniques.


Asunto(s)
Técnicas de Química Analítica/instrumentación , Técnicas de Química Analítica/métodos , Nanotecnología/instrumentación , Nanotecnología/métodos , Proteínas/química , Animales , Productos Biológicos/química , Calorimetría/métodos , Hidrodinámica , Luz , Dispersión de Radiación , Albúmina Sérica Bovina/química
5.
Pharm Res ; 28(9): 2302-10, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21560019

RESUMEN

PURPOSE: To evaluate Taylor dispersion analysis (TDA) as a novel method for determination of hydrodynamic radius of therapeutic peptides and proteins in non-stressed and stressed formulations and to compare it with dynamic light scattering (DLS). METHODS: The hydrodynamic radius of oxytocin, bovine serum albumin, various monoclonal antibodies (type IgG) and etanercept at concentrations between 0.05 and 50 mg/ml was determined by TDA and DLS. IgGs and etanercept were stressed (elevated temperatures) and analyzed by TDA, DLS and HP-SEC. RESULTS: TDA and DLS were comparable in sizing non-stressed peptides and proteins in a concentration range of about 0.5 to 50 mg/ml. TDA performed well even at lower concentrations, where DLS tends to provide theoretically high values of the Z-average radius. However, because of differences in the detection physics, DLS was more weighted towards the detection of aggregates in stressed formulations than TDA. Advantageously, TDA was also able to size the small peptide oxytocin, which was not feasible by DLS. CONCLUSION: TDA allows the accurate determination of the hydrodynamic radius of peptides and proteins over a wide concentration range, with little interference from excipients present in the sample. It is marginally less sensitive than DLS in detecting size increase for stressed protein samples.


Asunto(s)
Biofarmacia/métodos , Péptidos/química , Preparaciones Farmacéuticas/química , Multimerización de Proteína , Proteínas/química , Biofarmacia/estadística & datos numéricos , Química Farmacéutica , Cromatografía en Capa Delgada , Diseño de Fármacos , Estabilidad de Medicamentos , Excipientes/química , Calor , Hidrodinámica , Luz , Simulación de Dinámica Molecular , Conformación Proteica , Estabilidad Proteica , Dispersión de Radiación
6.
Int J Pharm ; 411(1-2): 64-8, 2011 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-21440611

RESUMEN

The escalating number of new therapeutic biopharmaceuticals being developed and their high value increases the need for the development of novel analytical technologies. Faster analysis time, high accuracy, low sample consumption and the ability to monitor process flow are all essential prerequisites. We evaluate a novel analytical instrument that combines UV area imaging and Taylor dispersion analysis (TDA) to determine the hydrodynamic radius of proteins and small molecules in solution. Benchmarking the results against dynamic light scattering, we report the influence of injection system, injection volume, flow rates, analyte concentration and highlight the importance of washing procedures. Issues arising from the manual injection valve in the alpha laboratory system that led to high standard deviations were eliminated by incorporating an automated injector in a beta system. The hydrodynamic radii obtained show good correlation with literature values and in most cases a relative standard deviation of less than 5%. The system is fully automated after coupling to the CE which allows for multiple injections and sample/buffer changes without operator intervention. The small sample size (approx. 60 nL), the lack of sample preparation required, and the speed of analysis (approx. 2-3 mins) makes this instrument highly applicable to the real-time analysis of inherently unstable, high cost biopharmaceutical materials where understanding their aggregation state and size is important.


Asunto(s)
Automatización de Laboratorios/métodos , Equipos y Suministros , Nanoestructuras/análisis , Preparaciones Farmacéuticas/análisis , Análisis por Matrices de Proteínas/métodos , Proteínas/análisis , Hidrodinámica , Peso Molecular , Nanoestructuras/química , Preparaciones Farmacéuticas/química , Proteínas/química , Radio (Anatomía) , Soluciones
7.
Int J Pharm ; 382(1-2): 67-72, 2009 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-19682563

RESUMEN

The stabilizing ability of the excipient on pharmaceutically relevant proteins for potential therapeutic use is an extensive area of research but the effect the protein has on the excipient is rarely reported. The influence of two model proteins on the polymorphic behaviour of mannitol during spray drying was therefore investigated. Spray dried mannitol/protein blends were characterised structurally using X-ray powder diffraction (XRPD) and Fourier transform Raman spectroscopy (FT-Raman) and thermally by differential scanning calorimetry (DSC) and also thermogravimetric analysis (TGA). To assess the long term storage stability, samples were subjected to conditions of elevated temperature and relative humidity (RH). Structural and thermal analysis of the samples showed that upon spray drying mannitol could be completely amorphous or crystalline dependent on the protein co-spray dried. Upon storage at elevated temperature and RH different polymorphic forms of mannitol (beta and delta) were evident again dependent on the protein co-spray dried. Under the conditions employed there was a polymorph directing effect on mannitol dependent on the protein with which it was co-spray dried with co-solute effects on relative water levels being indicated as a major factor in directing the polymorph.


Asunto(s)
Excipientes/química , Manitol/química , Muramidasa/química , Tecnología Farmacéutica/métodos , Tripsina/química , Rastreo Diferencial de Calorimetría , Química Farmacéutica , Cristalización , Cristalografía por Rayos X , Desecación , Composición de Medicamentos , Estabilidad de Enzimas , Análisis de Fourier , Humedad , Difracción de Polvo , Espectrometría Raman , Temperatura , Termogravimetría
8.
Drug Dev Ind Pharm ; 35(6): 712-8, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19514986

RESUMEN

BACKGROUND: Following the production of spray-dried mannitol powders, it is essential that the polymorphic content of each individual product is completely characterized. The implications of the polymorphic behavior of mannitol are immense. The appearance or disappearance of a crystalline form within a dosage form can have costly repercussions and lead to a dosage form being withdrawn. METHOD: In this study, commercially available and laboratory-produced spray-dried mannitol products were characterized to establish the polymorphic content of each. Their polymorphic behavior was also characterized after laboratory scale pharmaceutical processes. Thermal analysis employed differential scanning calorimetry, thermogravimetric analysis, and isothermal microcalorimetry. Structural analysis of the samples was obtained using X-ray powder diffraction and Fourier transform Raman spectroscopy. RESULTS: Structural analysis revealed that alpha- and beta- polymorphic forms were present in the commercial samples and some contained a mixture of polymorphs. Reprocessing employing spray drying indicated alpha- to beta- polymorphic transitions occurred within some of the samples. CONCLUSION: It is essential that preformulation studies where spray-dried mannitol products are to be employed must take into account its polymorphic behavior upon supply, processing, and subsequent storage.


Asunto(s)
Excipientes/química , Manitol/química , Calorimetría/métodos , Rastreo Diferencial de Calorimetría , Química Farmacéutica/métodos , Cristalización , Almacenaje de Medicamentos , Polvos , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría , Difracción de Rayos X
9.
Eur J Pharm Sci ; 33(3): 294-305, 2008 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-18262776

RESUMEN

The inherent instability of proteins when isolated from their native conditions creates the necessity of suitable stabilisation techniques. Because of the instability of proteins in solution it is often necessary to produce them as solid formulations. A method of producing relatively stable, solid protein pharmaceuticals is to incorporate them with a suitable excipient into an amorphous matrix by dehydration. The use of spray dried multiple excipient/single protein blends was compared to single excipient/protein systems using lysozyme as a model protein to establish the stabilising ability of such systems. Unprocessed controls and spray dried samples were characterised structurally by X-ray powder diffraction and Fourier transform Raman spectroscopy and also thermally by differential scanning calorimetry and thermogravimetric analysis. Retained lysozyme activity was assayed enzymatically. To assess long-term stability, samples were subjected to conditions of elevated temperature and relative humidity (RH) 40 degrees C/75% RH. Structural and thermal analysis of samples revealed that mannitol/trehalose spray dried excipient/lysozyme blends were completely amorphous upon production but partially recrystallised upon storage at elevated temperature and RH. Biological activity assays revealed that samples containing trehalose retained the highest percentage activity. Under the conditions employed mannitol/trehalose systems stabilise lysozyme more effectively than single excipient systems due to their ability to form amorphous products.


Asunto(s)
Excipientes/química , Manitol/química , Muramidasa/química , Sorbitol/química , Trehalosa/química , Rastreo Diferencial de Calorimetría , Composición de Medicamentos , Estabilidad de Medicamentos , Excipientes/farmacología , Manitol/farmacología , Micrococcus/efectos de los fármacos , Muramidasa/farmacología , Sorbitol/farmacología , Termogravimetría , Trehalosa/farmacología , Difracción de Rayos X
10.
Int J Pharm ; 349(1-2): 61-5, 2008 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-17884312

RESUMEN

Trace inorganic impurities in active pharmaceutical ingredients (APIs) while having limited toxicological significance might affect the down stream processing properties of those substances. The level of impurities in paracetamol batches was quantified and mapped using inductively coupled polarization mass spectrometry (ICP-MS) and scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX). The physical form of samples was assessed using X-ray powder diffraction (XRPD) and characterised thermally using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Surface properties were evaluated using inverse gas chromatography (IGC) and moisture sorption. Size distribution was measured using an aerosizer with dry powder dispersion. Physical analysis confirmed that the batches were of the same physical form and particle size distribution was shown to be similar. The SEM-EDX analysis however revealed the presence of aluminium on the surface of particles. This was supported by ICP-MS analysis, which showed different levels of aluminium between batches ranging from 0.1 to 5.6 ppm. IGC indicated that the batches with the highest aluminium content had the highest dispersive free energy. Differences in levels of inorganic impurities typically not considered significant in drug substance specifications correspond with differences in physical properties of APIs, with potential downstream consequences for processing and finished product performance.


Asunto(s)
Acetaminofén/química , Analgésicos no Narcóticos/química , Absorción , Rastreo Diferencial de Calorimetría , Fenómenos Químicos , Química Física , Cromatografía de Gases , Contaminación de Medicamentos , Microanálisis por Sonda Electrónica , Humedad , Espectrometría de Masas , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Temperatura
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