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

Haitian State Hospital Orthopedic Grand Rounds Series: A Virtual Curriculum to Address Global Surgery Needs

Background: Orthopedic Relief Services International (ORSI), in partnership with the Foundation for Orthopedic Trauma and the department of Orthopedic Surgery of La Paix University Hospital in Haiti, has developed a year-round Orthopedic Grand Round series. This series is moderated by Haitian faculty, features presentations by American orthopedic surgeons, and is broadcast to major state hospitals in Haiti for residents and attendings. Objective: To introduce clinical concepts and increase knowledge in an area that is medically underserved, especially in the field of orthopedics, through lectures that tailor to the educational needs of Haiti. Methods: Topics for lecture series are requested by Haitian attending orthopedic surgeons and residents in collaboration with American orthopedic surgeons to meet the educational needs of the residents in Haiti. These lectures reflect the case mix typically seen at state hospitals in Haiti and consider the infrastructural capacity of participating centers. Grand rounds are held an average of twice per month for an hour each, encompassing an educational lesson followed by an open forum for questions and case discussion. Feedback is taken from Haitian residents to ensure the sessions are beneficial to their learning. Findings and Conclusions: To date 95 sessions hosted by 32 lecturers have been completed over Zoom between the US and Haiti. The fourth year of the lecture series is currently ongoing with an expansion of topics. In an underserved medical area such as Haiti, programs that educate local surgeons are crucial to continuing the growth and development of the medical community. Programs like this have the potential to contribute to the educational infrastructure of countries in need, regardless of the specialty. The model of this program can be used to produce similar curricula in various specialties and areas around the world

Small area analysis methods in an area of limited mapping : exploratory geospatial analysis of firearm injuries in Port-au-Prince, Haiti

Background: The city of Port-au-Prince, Haiti, is experiencing an epidemic of firearm injuries which has resulted in high burdens of morbidity and mortality. Despite this, little scientific literature exists on the topic. Geospatial research could inform stakeholders and aid in the response to the current firearm injury epidemic. However, traditional small-area geospatial methods are difficult to implement in Port-au-Prince, as the area has limited mapping penetration. Objectives of this study were to evaluate the feasibility of geospatial analysis in Port-au-Prince, to seek to understand specific limitations to geospatial research in this context, and to explore the geospatial epidemiology of firearm injuries in patients presenting to the largest public hospital in Port-au-Prince. Results: To overcome limited mapping penetration, multiple data sources were combined. Boundaries of informally developed neighborhoods were estimated from the crowd-sourced platform OpenStreetMap using Thiessen polygons. Population counts were obtained from previously published satellite-derived estimates and aggregated to the neighborhood level. Cases of firearm injuries presenting to the largest public hospital in Port-au-Prince from November 22nd, 2019, through December 31st, 2020, were geocoded and aggregated to the neighborhood level. Cluster analysis was performed using Global Moran’s I testing, local Moran’s I testing, and the SaTScan software. Results demonstrated significant geospatial autocorrelation in the risk of firearm injury within the city. Cluster analysis identified areas of the city with the highest burden of firearm injuries. Conclusions: By utilizing novel methodology in neighborhood estimation and combining multiple data sources, geospatial research was able to be conducted in Port-au-Prince. Geospatial clusters of firearm injuries were identified, and neighborhood level relative-risk estimates were obtained. While access to neighborhoods experiencing the largest burden of firearm injuries remains restricted, these geospatial methods could continue to inform stakeholder response to the growing burden of firearm injuries in Port-au-Prince

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

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Carbapenem use in French hospitals: A nationwide survey at the patient level.

International audienceThe objective of this study was to evaluate the characteristics of carbapenem use in French healthcare settings in order to guide future actions. Healthcare facilities voluntarily participated in a nationwide cross-sectional survey in 2011. Medical data and reasons for carbapenem treatment (CPR) and discontinuation were recorded for all patients treated with carbapenems. A total of 2338 patients were recorded by 207 facilities. The median duration of CPR was 8 days, and 31.4% of patients received CPR for >10 days. An antibiotic consultant was involved in the initial choice of CPR in 36.8% of cases. CPR was chosen on an empirical (EP) basis for 1229 patients (52.6%), mainly because of severe sepsis (48.6%) or a perceived risk of bacterial resistance (33.7%). Among EP patients, de-escalation was more frequent in the case of intervention of an antibiotic consultant (35.1%) than without intervention (22.9%) (P<0.01). Among the 1109 patients receiving CPR initially based on bacteriological results, 607 (54.7%) had ESBL-producing Enterobacteriaceae and 397 (35.8%) had Gram-negative bacilli susceptible to at least one β-lactam other than carbapenems or to fluoroquinolones. Among the latter, de-escalation was performed in 59 cases (14.9%). The intervention of an antibiotic consultant did not favour de-escalation in this group. In conclusion, carbapenems are frequently used for treating suspected or confirmed multidrug-resistant bacteria, and overall CPR duration is long. De-escalation is frequently not implemented despite isolates being susceptible to other drugs. More frequent antibiotic consultant intervention may help to decrease carbapenem use in the case of EP treatment

Confinement, desolvation, and electrosorption effects on the diffusion of ions in nanoporous carbon electrodes

International audienceSupercapacitors are electrochemical devices which store energy by ion adsorption on the surface of a porous carbon. They are characterized by high power delivery. The use of nanoporous carbon to increase their energy density should not hinder their fast charging. However, the mechanisms for ion transport inside electrified nanopores remain largely unknown. Here we show that the diffusion is characterized by a hierarchy of time scales arising from ion confinement, solvation, and electrosorption effects. By combining electrochemistry experiments with molecular dynamics simulations, we determine the in-pore conductivities and diffusion coefficients and their variations with the applied potential. We show that the diffusion of the ions is slower by 1 order of magnitude compared to the bulk electrolyte. The desolvation of the ions occurs on much faster time scales than electrosorption

Review of applied and tested control possibilities for energy flexibility in buildings

This report, one of the deliverables for the IEA Annex 67 on Energy Flexible Buildings, provides a comprehensive review of control methodologies to provide energy flexibility in buildings. The reviewed methodologies range from classical rule-based control to model predictive control and reinforcement learning based control. The objective of the report is to help practitioners formulate their optimal control problems according to the framework which best suits their problem.status: Published onlin