The development of direct extrusion-injection moulded zein matrices as novel oral controlled drug delivery systems

Purpose: To evaluate the potential of zein as a sole excipient for controlled release formulations prepared by hot melt extrusion. Methods: Physical mixtures of zein, water and crystalline paracetamol were hot melt extruded (HME) at 80°C and injection moulded (IM) into caplet forms. HME-IM Caplets were characterised using differential scanning calorimetry, ATR-FTIR spectroscopy, scanning electron microscopy and powder X-ray diffraction. Hydration and drug release kinetics of the caplets were investigated and fitted to a diffusion model. Results: For the formulations with lower drug loadings, the drug was found to be in the non-crystalline state, while for the ones with higher drug loadings paracetamol is mostly crystalline. Release was found to be largely independent of drug loading but strongly dependent upon device dimensions, and predominately governed by a Fickian diffusion mechanism, while the hydration kinetics shows the features of Case II diffusion. Conclusions: In this study a prototype controlled release caplet formulation using zein as the sole excipient was successfully prepared using direct HME-IM processing. The results demonstrated the unique advantage of the hot melt extruded zein formulations on the tuneability of drug release rate by alternating the device dimensions

Selbstbau-Fibel Erfahrungen und Hinweise zum Umbau von Reihenhaeusern

TIB: RN 2615 (114) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Imminent Capture and Noncompliance: Probing Deterrence in Extreme Environments

Understanding how deterrence operates under extreme conditions is both elusive and important. Studying suspect noncompliance in the form of flight during police-involved vehicle chases provides the opportunity to do this. These are crimes where the certainty of detection could not be higher, yet noncompliance is the end result and arguably comes because of the enhanced sanction risk rather than the obverse (deterrence) or in spite of it (defiance). Drawing from a qualitative sample of 25 auto thieves who have fled from the police, we explore their pre-chase perceptions, their motives for flight, and their decision-making processes during flight to probe the theoretical boundaries of perceptual deterrence. To this end, we pay particular attention to the mediating role of ambiguity aversion and belief updating in reconciling two seemingly inconsistent theoretical perspectives: risk framing and rational choice