Impact of downstream processing on crystal quality during the precipitation of a pharmaceutical product

In pharmaceutical industries, active pharmaceutical ingredients (API) are made of crystals whose properties must be controlled because they influence the end-use properties of the drug. Even if crystal quality is mainly determined during the precipitation step, downstream processing also has an influence. In this study, the influence of washing on the crystal size and shape was analyzed. For the API being considered, different impurities have to be removed from the final suspension by filter cake washing. The efficiency of the washing steps was measured by different types of characterization on the solid phase (differential scanning calorimetry, scanning electron microscopy, and size distribution) and on the remaining filtrate (concentration of impurities). A second component also coprecipitates with the API. A specific study has been carried out on the withdrawal of this by-product and on its impact on the evolution of the crystalline form during washing steps. It was found that three filter cake washings allow us to remove all the impurities and to obtain a pure crystalline form

La comptabilité peut-elle dire le vrai ?

Les comptes des entreprises ont récemment défrayé la chronique. Il faut dire que la comptabilité peut mentir, comme le montrera l’histoire du redressement spectaculaire de l’entreprise Cacahuète S.A. Peut-elle même dire le vrai ? La comptabilité, loin d’être une science exacte, est un art du consensus. Or ce consensus a achevé de se lézarder avec la bulle internet, faisant apparaître au grand jour des failles dans le système d’information financière. Trouvera-t-on de nouveaux consensus

Influence of pH, Temperature and Impurities on the Solubility of an Active Pharmaceutical Ingredient (API)

Solubility, which defines the liquid /solid equilibrium, is a key parameter to control a crystallization process. This work is focused on the effects of pH, temperature and impurities on the aqueous solubility of an Active Pharmaceutical Ingredient (API).As the API is a weak acid (pKa = 3.7), its solubility increases with the pH. On the basis of the experimental curve of solubility, a model was defined to fit the evolution of the solubility as a function of pH. In the case of this compound, studies revealed a weak influence of the temperature in comparison with the pH. So, the solubility of the compound is slightly impacted by the temperature.Some experiments were carried out in order to compare the solubility of the API, at the same pH and temperature, for different concentrations of impurities found in the process. The results revealed a solubility increase in presence of acetic acid and a high solubility decrease in presence of sodium chloride. By carrying out experiments on common ions salts, the anion chloride Cl- has been identified as the cause of the solubility decrease

Transforming Basic Robotic Platforms into Easily Deployable and Web Remotely Controllable Robots

International audienceThis paper describes a way to transform basic robotic platforms into Web remotely controllable robots. Our goal is to achieve robot deployment anywhere, at anytime, at low-cost. As soon as full or even restricted Internet access is available (WiFi or 3G), the robot can be deployed and Webcontrolled. The distant user can send commands to the robot and monitor the state of the robot. For example, the distant user can make the robot move and get snapshots taken by the robot

Characterization of the conglomerate form of acetyl-dl-leucine by thermal analysis and solubility measurements

Starting from a mixture of enantiomers in solution, crystallization can generate different types of crystals. In order to determine which type of crystal is obtained in the case of acetylleucine, an active pharmaceutical ingredient (API), analytical methods have been used to partially elucidate the binary and ternary phase diagrams of the system composed of the two enantiomers and water.The melting temperature phase diagram of this compound has been obtained by using differential scanning calorimetry (DSC) analyzes. The results show that it is characteristic of a conglomerate. This mode of crystallization has also been confirmed by X-ray powder diffraction analysis. Solubility measurements of enantiomerical mixtures in water enabled the determination of the ternary diagram of solubility. The empiric Meyerhoffer double solubility rule has been modified, due to the characterization of interactions between enantiomers

Champs Gaussiens conditionnels pour la modélisation inter-échelle de textures : Application à la super-résolution en télédétection satellitaire de l'océan

National audienceCet article s'intéresse à la modélisation et la simulation inter-échelle de textures. Nous considérons ici des modèles de champs gaussiens conditionnels obtenus comme solutions d'équations aux dérivées partielles stochastiques. Ces modèles sont utilisés pour la synthèse de texture non-stationnaire tout en ayant un contrôle sur les propriétés spectrales, statistiques et géométriques des champs générés. Nous montrons que ces modèles peuvent s'obtenir à l'aide d'une convolution non-stationnaire d'un bruit blanc gaussien par un opérateur linéaire associée à la la fonction de covariance, qui peut notamment prendre en considération des propriétés géométriques d'anisotropie. Les versions discrétisées de ces modèles correspondent à des modèles AR 2D, obtenus à l'aide de la représentation harmonisable de l'opérateur différentiel. Ces différents opérateurs sont explicités de manière analytique dans le cas des champs dits Matérn. L'apport de ces méthodes par rapport à des versions non paramétriques stationnaires est discuté. Une application à la super-résolution basée texture d'images satellitaires associées à des dynamiques turbulentes à la surface de l'océan permet de valider le modèle proposé

Helping and monitoring robots at low cost

nombre de pages : 6National audienceThrough European countries the dependency ratio of elders and people with disability will rise in the next years. To avoid a degradation of the life quality of dependant persons, they may be maintained in their home. To ensure people safety and avoid isolation problems, some mechanisms are needed. We propose a new method, the X-development method, to guide generic product design from end-to-end. In this paper, the design is focused on robots for dependant people. To respect the environmental constraints and to reduce the amount of waste, the robots have to be designed properly. The aim of the X-development method is to ease the manufacturing process thanks to the tight association between the modelling and design phases of smart systems. Our robots are remotely controlled in order to achieve monitoring and social tasks. Caregivers or relatives can control each robot to interact with the dependant person. The robots increase the social interaction of dependant people. During the design phase, we keep in mind to maintain the price of the robot as cheap as possible, because it is the key point in the generalization of this one

Spatio-temporal segmentation and estimation of ocean surface currents from satellite sea surface temperature fields

International audienceThe use of satellite Sea Surface Temperature (SST) fields to retrieve zonal and meridional surface currents (U,V) is now a widespread idea. Since the classical approach involves temporal differencing of SST fields, we investigate in this paper the extent to which mesoscale ocean dynamics may be decomposed into a superposition of dynamical modes, characterized by different linear relationships between surface currents and temperature fields. Based on a completely observation-driven approach, we propose a latent class regression model from local satellite surface currents and patches of SST measurements. Applied to the highly dynamical Agulhas region, we demonstrate and discuss the geophysical relevance of the proposed mixture model to achieve a spatio-temporal segmentation and tracking of the ocean surface dynamical modes. Moreover, we show the accuracy of the proposed model to predict mesoscale surface currents from SST single maps