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Qian Z.,New Jersey Institute of Technology | Wang P.,University of Rhode Island | Gogos C.G.,New Jersey Institute of Technology | Gogos C.G.,Polymer Processing Institute
Polymer Engineering and Science | Year: 2012

A novel simultaneous, in situ milling and coating method carried out in a fluid energy mill (FEM) is applied for the first time to prepare nanoparticle-coated CaCO 3 (CC) additives for polymer composite materials. Simply milled (without coating) CC particles and as-received CC particles were used as references for comparison. The effects of the grinding pressure and the fraction of the nanoparticles on the size and flowability of CC particles were studied. The composites made with polypropylene (PP) and this specially prepared CC have higher elongation at break, elastic modulus, and impact strength, compared with the PP filled with uncoated CC. The thermal and thermo-oxidative stabilities of PP are improved as well by introducing the milled and nanoparticle-coated CC. © 2011 Society of Plastics Engineers.

Suwardie H.,Polymer Processing Institute | Wang P.,University of Rhode Island | Todd D.B.,Polymer Processing Institute | Panchal V.,U.S. Army | And 3 more authors.
European Journal of Pharmaceutics and Biopharmaceutics | Year: 2011

There is a growing interest of extrusion drug and polymer together to manufacture various solid dosages. In those cases, the drug's release profiles are greatly affected by the miscibility of two materials. The goal of this study is to test the drug's solubility in molten polymer and obtain the mixture's rheological properties for the purpose of optimizing the extrusion process. The dynamic and steady viscosities of APAP-PEO mixture were determined using oscillatory and capillary rheometers. The curves of viscosity vs. drug loading generally have a "V" shape, and the minimal point gives the APAP's solubility in PEO. The test results suggest that different dynamic methods lead to essentially the same solubility data. At high shear rates, the mixtures show shear thinning behavior and the viscosity becomes less sensitive to the drug loading. In other words, it is desirable to use a low shear rate in order to deduce the drug's solubility in polymer from the viscosity data. On the other hand, viscosity data at high shear rates are more representative of the materials' rheological properties during extrusion. © 2011 Elsevier B.V. All rights reserved.

Terife G.,New Jersey Institute of Technology | Wang P.,University of Rhode Island | Faridi N.,Polymer Processing Institute | Gogos C.G.,Polymer Processing Institute | Gogos C.G.,New Jersey Institute of Technology
Polymer Engineering and Science | Year: 2012

The hot melt mixing (HMM) process was used to dissolve 30 wt% of a model drug, indomethacin (INM), in Soluplus® a water soluble polymer excipient. Comprehensive characterization of the HMM-prepared samples, using differential scanning calorimetry, X-ray diffraction, Fourier Transform Infrared spectroscopy, and optical microscopy, strongly suggests that INM was in amorphous state, forming a solid solution with the polymer. Furthermore, to understand the impact of foaming on INM's release profile, the HMM product was foamed in a batch process using supercritical carbon dioxide (CO 2). Dissolution tests of HMM and reference samples were conducted in aqueous solutions with pH 7.4 and 1.2. In all cases INM's release showed strong pH-dependency; faster release and a greater amount of INM was released at pH 7.4 than at pH 1.2. For pure INM and the physical mixture, the drug's ionizable character results in the observed pH-dependency. While for the HMM samples it is also a consequence of theformation of hydrogen bonds between Soluplus® and INM which hinder polymer dissolution at pH 1.2. It was observed that the release rate of INM from different sample types at pH 7.4 decreased in the following sequence: foamed HMM > unfoamed HMM > crystalline INM > physical mixture. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers Copyright © 2012 Society of Plastics Engineers.

Teng S.,New Jersey Institute of Technology | Wang P.,University of Rhode Island | Zhang Q.,New Jersey Institute of Technology | Gogos C.,New Jersey Institute of Technology | Gogos C.,Polymer Processing Institute
Powder Technology | Year: 2011

The particulate motions and collisions inside the Fluid Energy Mill were simulated by coupling the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD). The influences of the operating conditions on the particulate motions and collisions were investigated to further explain size reduction process. The high-speed grinding air streams introduced through narrow inlets selectively accelerate the particles located near the inlets. Those particles are more likely to hit the wall at a high speed, or collide with other particles due to the velocity difference. The simulation results also reveal that abrasion is the dominant breakage mechanism during the particle-particle collisions. On the other hand, with the increase of number of particles in the chamber, the particle-particle collision becomes more important for milling, compared to the particle-wall collision. The side-swipe particle-particle collisions also facilitate transferring of coating materials among particles, which explains the simultaneous milling and coating process recently developed in our lab. © 2011 Elsevier B.V.

Liu H.,New Jersey Institute of Technology | Zhu L.,Polymer Processing Institute | Wang P.,University of Rhode Island | Zhang X.,New Jersey Institute of Technology | Gogos C.G.,New Jersey Institute of Technology
Advances in Polymer Technology | Year: 2012

This experimental study examines the evolution of the extent of dissolution of the active pharmaceutical ingredient (API) indomethacin (INM) into the polymer excipient Eudragit E PO (E PO) on four screw configurations processed in an APV 15 mm corotating twin screw extruder. The screws were pulled out and quenched by water, which allowed for quick access to the processed stream carcass. Polarized light microscopy (PLM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR), were employed to investigate the evolution of INM's dissolution into the molten excipient along the extrusion direction. The FT-IR results show that kneading blocks accelerate the complete dissolution process. The unique capability of fully filled kneading blocks in mixing and melting associated with the dissolution of API into polymeric excipient matrix was discussed. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 31: 331-342, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20256 Copyright © 2011 Wiley Periodicals, Inc.

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