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Karner S.,University of Graz | Anne Urbanetz N.,University of Graz | Anne Urbanetz N.,Research Center Pharmaceutical Engineering GmbH
Journal of Aerosol Science | Year: 2011

The aim of this work is to give an overview about the literature available on the topic of electrostatic charge in pharmaceutical powders. The main focus is on powders used in dry powder inhaler devices. Pharmaceutical powders mainly consist of fine particles of electrical insulating materials. On the one hand, the insulating properties disfavor electrostatic charge dissipation. On the other hand, small particle sizes in general result in high cohesive forces in relation to gravitational forces. For these reasons the powder may show very cohesive characteristics. In order to overcome the problems associated with cohesivity and deposit the active pharmaceutical ingredient in the deeper regions of the lung, it is important to understand how electrostatic charge is acquired and by which factors acquisition is influenced. The work includes an overview about different operations in pharmaceutical process engineering in which charge may be introduced and the associated influencing process variables. Furthermore related topics like the utilization of electrostatic charge for improving lung deposition of powders intended for pulmonary drug delivery are reviewed. To complete the overview several static and dynamic measuring procedures for net charge and charge distribution are presented and compared. © 2011 Elsevier Ltd.


Stankovic M.,University of Groningen | Stankovic M.,Research Center Pharmaceutical Engineering GmbH | Frijlink H.W.,University of Groningen | Hinrichs W.L.J.,University of Groningen
Drug Discovery Today | Year: 2015

Over the past few decades hot melt extrusion (HME) has emerged as a powerful processing technology for the production of pharmaceutical solid dosage forms in which an active pharmaceutical ingredient (API) is dispersed into polymer matrices. It has been shown that formulations using HME can provide time-controlled, sustained and targeted drug delivery, and improved bioavailability of poorly soluble drugs. In this review, the basic principles of the HME process are described together with an overview of some of the most common biodegradable and nonbiodegradable polymers used for the preparation of different formulations using this method. Further, the applications of HME in drug delivery and analytical techniques employed to characterize HME products are addressed. © 2015 Elsevier Ltd.


Karner S.,Graz University of Technology | Urbanetz N.A.,Research Center Pharmaceutical Engineering GmbH
Powder Technology | Year: 2013

Inhalation powders may be charged by triboelectrification upon aerosolization and release of the powder from the inhaler device due to frequent contacts and high impact velocities between the particles and the inhaler material. This is particularly challenging in dry powder inhaler (DPI) technology where usually adhesive mixtures of carrier particles in the size range of 50 μm-200 μm and active pharmaceutical ingredient (API) particles in the size range of 0.5 μm-5 μm are used. In these adhesive mixtures it is crucial that the API particles adhere to the coarser carrier particles to ensure good flowability and dosing behavior. However during aerosolization the API particles should detach from the carriers in order to reach the deeper lung. This means that the performance of such adhesive mixtures used in DPI devices is strongly affected by inter-particle forces which are further affected by electrostatic charge. Sign and magnitude of the arising charge is on the one hand influenced by the contacting material, relative humidity and impact velocity and on the other hand by particle characteristics like particle size, particle shape and surface roughness.For these reasons the aim of this work is to investigate which factors actually influence the charging process during powder aerosolization and release from the inhaler and how it can be controlled. In the present study the influence and interactions of four practice-relevant factors is checked using statistical design of experiments. These are the carrier particle size, the aerosolization air flow rate, the API content in the adhesive mixtures and the addition of carrier fines < 40 μm. The experiments are performed using the Novolizer® as DPI device. Electrostatic charge measurements are conducted using an open-end Faraday cup. The study revealed that the netcharge increases with an increasing amount of carrier fines and an increasing air flow rate. Further the netcharge decreases with increasing particle size and the presence of API. Finally investigations on the dependence of tribo-charging on the number of actuations of the device revealed that the netcharge arising on adhesive mixtures released in 50 consecutive doses from the DPI is almost the same for each dose at an air flow rate of 60. l/min whereas at 90. l/min there is a noticeable trend of decreasing netcharge over the number of actuations. © 2012 Elsevier B.V.


Patent
Research Center Pharmaceutical Engineering GmbH and Research Center for Non Destructive Testing GmbH | Date: 2014-04-29

A method and a device for monitoring a property of a coating of a solid dosage form during a coating process forming the coating of the solid dosage form are provided. The device comprises a coating apparatus configured for forming the coating on the solid dosage form, and a monitoring apparatus configured for monitoring the property of the coating of the solid dosage form in process, wherein at least a part of the monitoring apparatus is located so as to have insight in an interior of the coating apparatus, the interior accommodating the solid dosage form to be coated and a precursor for forming the coating, and wherein the monitoring apparatus is configured for monitoring the property of the coating of the solid dosage form simultaneously with and during a coating process using low coherence interferometry.


Radeke C.A.,Research Center Pharmaceutical Engineering GmbH | Glasser B.J.,Rutgers University | Khinast J.G.,Research Center Pharmaceutical Engineering GmbH | Khinast J.G.,University of Graz
Chemical Engineering Science | Year: 2010

Granular flows are extremely important for the pharmaceutical and chemical industry, as well as for other scientific areas. Thus, the understanding of the impact of particle size and related effects on the mean, as well as on the fluctuating flow field, in granular flows is critical for design and optimization of powder processing operations. We use a specialized simulation tool written in C and CUDA (Compute Unified Device Architecture), a massive parallelization technique which runs on the Graphics Processing Unit (GPU). We focus on both, a new implementation approach using CUDA/GPU, as well as on the flow fields and mixing properties obtained in the million-particlerange. We show that using CUDA and GPUs, we are able to simulate granular flows involving several millions of particles significantly faster than using currently available software. Our simulation results are intended as a basis for enhanced DEM simulations, where fluid spraying, wetting and fluid spreading inside the powder bed is considered. © 2010 Elsevier Ltd.

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