Search results for "Methods"

Microparticle preparation by a propylene carbonate emulsification-extraction method

2018

Abstract The use of various harmful organic solvents for microparticle formulations is still widespread. Here, an alternative low toxicity solvent (propylene carbonate; PC) is proposed for the preparation of poly(lactic-co-glycolic-acid) (PLGA) microparticles. Based on the classical emulsification-solvent extraction methodology, the use of PC offers the unique advantage of an additional solvent extraction step using hydrolytic solvent cleavage during microparticle preparation. Spherical, rough-surfaced microparticles were obtained with a volume median diameter range from 20 to 60 µm. The residual PC content has been identified to be the major factor for the solidification hindrance, leading…

3D-Printed Solid Dispersion Drug Products.

2019

With the well-known advantages of additive manufacturing methods such as three-dimensional (3D) printing in drug delivery, it is disappointing that only one product has been successful in achieving regulatory approval in the past few years. Further research and development is required in this area to introduce more 3D printed products into the market. Our study investigates the potential of fixed dose combination solid dispersion drug products generated via 3D printing. Two model drugs&mdash

Predictive factors for sustained virological response after treatment with pegylated interferon α-2a and ribavirin in patients infected with HCV geno…

2014

BackgroundPrevious trials have often defined genotype 2 and 3 patients as an "easy to treat" group and guidelines recommend similar management.AimsThe present study looks for differences between the two genotypes and analyzes predictive factors for SVR.MethodsProspective, community-based cohort study involving 421 physicians throughout Germany. The analysis includes 2,347 patients with untreated chronic HCV genotype 2 (n = 391) and 3 (n = 1,956) infection treated with PEG-IFN α-2a plus ribavirin between August 2007 and July 2012.ResultsWhen compared with genotype 2 patients, those with genotype 3 were younger, had a shorter duration of infection, lower values of total cholesterol, LDL chole…

Transdermal therapy and diagnosis by iontophoresis

1997

Iontophoresis, the use of an electric current to drive charged molecules across the skin, has the potential to expand the feasible range of drugs for transdermal administration significantly. This method of delivery is being examined carefully with respect to higher-molecular-weight therapeutics (in particular, peptides and small proteins), which cannot be absorbed following oral administration and for which, at this time, an invasive injection remains the only option. In addition, the procedure of so-called 'reverse' iontophoresis would appear to represent a truly noninvasive approach for diagnostic monitoring of blood chemistry.

Interpretation of Ocular Melanin Drug Binding Assays. Alternatives to the Model of Multiple Classes of Independent Sites

2016

Melanin has a high binding affinity for a wide range of drugs. The determination of the melanin binding capacity and its binding affinity are important, e.g., in the determination of the ocular drug distribution, the prediction of drug effects in the eye, and the trans-scleral drug delivery. The binding parameters estimated from a given data set vary significantly when using different isotherms or different nonlinear fitting methods. In this work, the commonly used bi-Langmuir isotherm, which assumes two classes of independent sites, is confronted with the Sips isotherm. Direct, log-log, and Scatchard plots are used, and the interpretation of the binding curves in the latter is critically a…

Observational Approach and Perspective

1983

Well you did not cover more than half of my planned talk! (laughter). Let me comment on interferometric techniques, in particular speckle imaging which you mentioned. Doing speckle imaging with the largest telescopes now available will not give you better than the theoretical resolving power of the telescope. With a 4m telescope that is about 30 marc sec in the visible. That happens to be the radius of the supergiant Betelguese. So you are not going to achieve much with speckle imaging on these stars. One technique which has not been adequately exploited is that of lunar occultation which can give much better angular resolution than speckle, of the order of 2-3 marc sec. By using suitably c…

Mode-superposition correction method for deterministic and stochastic analysis of structural systems

2001

The role played by the modal analysis in the framework of structural dynamics is fundamental from both deterministic and stochastic point of view. However the accuracy obtained by means of the classical modal analysis is not always satisfactory. Therefore it is clear the importance of methods able to correct the modal response in such a way to obtain the required accuracy. Many methods have been proposed in the last years but they are meaningful only when the forcing function is expressed by an analytical function. Moreover in stochastic analysis they fail for white noise excitation. In the paper a method able to give a very accurate response for both deterministic and stochastic input is p…

Massive evaluation and analysis of Poincar�� recurrences on grids of initial data: a tool to map chaotic diffusion

2020

We present a novel numerical method aimed to characterize global behaviour, in particular chaotic diffusion, in dynamical systems. It is based on an analysis of the Poincar\'e recurrence statistics on massive grids of initial data or values of parameters. We concentrate on Hamiltonian systems, featuring the method separately for the cases of bounded and non-bounded phase spaces. The embodiments of the method in each of the cases are specific. We compare the performances of the proposed Poincar\'e recurrence method (PRM) and the custom Lyapunov exponent (LE) methods and show that they expose the global dynamics almost identically. However, a major advantage of the new method over the known g…

Lidar : traitement avancé des données et interprétation archéologique - cours 2016

2016

Les déterminants des compétences sociales des élèves de cycle III

2016

Les différences de réussite à l’école primaire traditionnellement étudiées par les chercheurs en éducation peuvent être analysées à la lumière des compétences et plus particulièrement des compétences sociales. Champ théorique encore en construction, les compétences sociales deviennent tout de même un « incontournable » pour les acteurs du système éducatif et pour la recherche en sciences de l’éducation. Par une approche pluridisciplinaire, cet article propose d’étudier quels sont les déterminants des compétences sociales à l’aide d’indicateurs sociodémographiques et scolaires largement empruntés dans les modèles d’explication des différences de réussite, auxquels sont associées des mesures …