Comparative static curing versus dynamic curing on tablet coating structures

International audienceCuring is generally required to stabilize film coating from aqueous polymer dispersion. This post-coating drying step is traditionally carried out in static conditions, requiring the transfer of solid dosage forms to an oven. But, curing operation performed directly inside the coating equipment stands for an attractive industrial application. Recently, the use of various advanced physico-chemical characterization techniques i.e., X-ray micro-computed tomography, vibrational spectroscopies (near infrared and Raman) and X-ray microdiffraction, allowed new insights into the film-coating structures of dynamically cured tablets. Dynamic curing end-point was efficiently determined after 4 h. The aim of the present work was to elucidate the influence of curing conditions on film-coating structures. Results demonstrated that 24 h of static curing and 4 h of dynamic curing, both performed at 60 degrees C and ambient relative humidity, led to similar coating layers in terms of drug release properties, porosity, water content, structural rearrangement of polymer chains and crystalline distribution. Furthermore, X-ray microdiffraction measurements pointed out different crystalline coating compositions depending on sample storage time. An aging mechanism might have occur during storage, resulting in the crystallization and the upward migration of cetyl alcohol, coupled to the downward migration of crystalline sodium lauryl sulfate within the coating layer. Interestingly, this new study clearly provided further knowledge into film-coating structures after a curing step and confirmed that curing operation could be performed in dynamic conditions

Comprehensive study of dynamic curing effect on tablet coating structure

International audienceThe dissolution method is still widely used to determine curing end-points to ensure long-term stability of film coatings. Nevertheless, the process of curing has not yet been fully investigated. For the first time, joint techniques were used to elucidate the mechanisms of dynamic curing over time from ethylcellulose (Aquacoat (R))-based coated tablets. X-ray micro-computed tomography (X mu CT), Near Infrared (NIR), and Raman spectroscopies as well as X-ray microdiffraction were employed as non-destructive techniques to perform direct measurements on tablets. All techniques indicated that after a dynamic curing period of 4 h, reproducible drug release can be achieved and no changes in the microstructure of the coating were any longer detected. X mu CT analysis highlighted the reduced internal porosity, while both NIR and Raman measurements showed that spectral information remained unaltered after further curing. X-ray microdiffraction revealed densification of the coating layer with a decrease in the overall coating thickness of about 10 pm as a result of curing. In addition, coating heterogeneity attributed to cetyl alcohol was observed from microscopic images and Raman analysis. This observation was confirmed by X-ray microdiffraction that showed that crystalline cetyl alcohol melted and spread over the coating surface with curing. Prior to curing, X-ray microdiffraction also revealed the existence of two coating zones differing in crystalline cetyl alcohol and sodium lauryl sulfate concentrations which could be explained by migration of these constituents within the coating layer. Therefore, the use of non-destructive techniques allowed new insights into tablet coating structures and provided precise determination of the curing end-point compared to traditional dissolution testing. This thorough study may open up new possibilities for process and formulation control

Développement d'un procédé de précipitation contrôlée pour obtenir des particules de principes actif de granulométrie réduite

BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

Real-time predictions of drug release and end point detection of a coating operation by in-line near infrared measurements

International audienc

Quelle éducation avec la Covid-19

APPEL A CONTRIBUTION : QUE NOUS APPREND LA PANDEMIE? Numéro HS Recherches et Educations (Juillet 2020) (HCERES 70ème section) Qu'est ce que la pandémie nous apprend de nos sociétés, de nos politiques de santé publique, des souverainetés épistémologiques de la recherche et des praxis individuelles et collectives? Solidarités ou/ et d'exclusions? Stratégies d'adaptation au confinement ou de rejet? Comment agit-on dans ce monde incertain, soumis à l'autorité des politiques de gestion d'un virus? Soumission volontaire à l'autorité ou organisation des résistances? Quels sont les savoirs exercés sur quels pouvoirs ? Quelles sont les légitimités et les responsabilités plurielles : individuelles, collectives, politiques et sociales ? Quels sont les usages sociaux et politiques des résultats de la recherche des experts ? Qu’apprenons nous des expériences de prévention individuelles, européennes et internationales ? Comment s’exercent les pouvoirs à partir des savoirs des épistémologies et des évidence-base medecine ? Comment l’histoire des épidémies pourrait répondre à notre présent ? Quel futur pour notre société après la pandémie ? Quelles seront nos inégalités sociales ? Vers quelles écologies ? Quelles résistances ? Quel mode de vie ? Quelles expériences corporelles de l’absence de toucher et de la distanciation ? Quelle croissance ? Quelle décroissance ? Quelles solidarités face à la techno-économique ? La revue Recherches & Educations lance un appel à contribution, multi disciplinaire, sur le « dispositif covid 19 » pendant le confinement imposé aux populations. Elle propose de réunir les textes critiques et réflexifs sur ce que nous apprend l’épidémie et la pandémie de nous même, de notre relation au vivant, à la mondialisation néolibérale, aux souverainetés de santé, au gouvernement des corps, de la psyché et de la vie, aux politiques de prévention, aux représentations de l’épidémie, aux pratiques corporelles visuelles et tactiles, aux modes de résistances et aux praxis du quotidien du présent et de demain. Texte à adresser (avant le 30 mai 2020) en 30.000 signes à [email protected] [email protected] [email protected]