Pellets by extrusion

Thoma K, Zeigler I. Investigations on the influence of the type of extruder for pelletization by extrusion-spheronization. I. Extrusion behavior of formulations. Drug Dev Ind Pharm 1998 24(5) 401-411. 

Powders, pastes and melts are pelleted by extrusion through a die followed by cutting. Binders and lubricants may need to be incorporated in the feed, but the process usually is not feasible for... 

In summary, fixed-bed processes have advantages in ease of scaleup and operation. The reactors operate in a downflow mode, with liquid feed trickling downward over the solid catalyst concurrent with the hydrogen gas. The usual catalyst is cobalt/molybdenum (Co/Mo) or nickel/molybdenum (Ni/Mo) on alumina (A1203) and contain 11-14% molybdenum and 2-3% of the promoter nickel or cobalt. The alumina typically has a pore volume of 0.5 ml/g. The catalyst is formed into pellets by extrusion, in shapes such as cylinders (ca. 2 mm diameter), lobed cylinders, or rings. 

Lindner, H. Kleinebudde, P. Use of Powdered Cellulose for the Production of Pellets by Extrusion/Spheronization. J. Pharm. Pharmacol. 1994, 46, 2-7. 

Powdered cellulose has been investigated as an alternative to microcrystalline cellulose as an agent to assist the manufacture of pellets by extrusion/spheronization/ ... 

Tomer G, Podczeck F, Newton JM. The influence of model drugs on the preparation of pellets by extrusion/spheronization 11 sphcronization parameters. Int J Pharm 2002 231 107-19. 

Mac Ritchie KA, Newton JM. Rowe RC. The evaluation of the rheological properties of lactose/microcrystalline cellulose and water mixtures by controlled stres.s rheometry and the relationship to the production of spherical pellets by extrusion/spheronization. Eur J Pharm... 

Lustig-Gustafsson C, Johal HK. Podczeck F, et al. The influence of water content and drug solubility on the formation of pellets by extrusion and spheronization. Eur J Pharm Sci 1999 8 147-52. 

Lindner H. Kleinebudde P. Use of powdered cellulose for the production of pellets by extrusion/spheronization J Pharm Pharmacol 1994 46 1-7. 

Basit AW, Newton JM, Lacy LF. Formation of ranitidine pellets by extrusion/spheronization with little or no microcry.stalline cellulose. Pharm Dev Tech 1999 4 499-505. 

Newton iM. Chatchawalsaisin J, Podczeck F. The influence of monoglycerides, mixtures and derivatives on the formation of pellets by extrusion/sf eronization. Pharm Tech ir 2005 l7(l2) 38-43. 

Tho I, Sande SA. Kleinebudde P. Pectinic acid, a novel excipient fOT the oduction of pellets by extrusion/ heronization preliminary studies. Eur J Pharm Biopharm 2002 54 95-9. 

Steckel H, Mindermann-Nogly F. Production of chitosan pellets by extrusion/spheronization Eur J Pharm Biopharm 2004 57 107-14. 

Some studies with filled and unfilled rigid PVC were made in our laboratory to describe the effect of chalk as additional stabilizer. A suspension PVC (K-value 70) with an organotin stabilizer (2 phr) and lubricants (1.8 phr) was used as the experimental material. A part of this compound was filled with a stearic acid coated calcium carbonate (10 phr) as an additional component. The PVC powder and the additives were mixed at a high speed in an intensive mixer. The received dry blends were pelletized by extrusion to get a better dispersion of the additives in the polymer material. Finally, the granulates were processed by injection molding to test specimens for measurements of mechanical properties. 

The polymer manufacturer, starting from raw materials like natural gas and other low molecular weight chemicals, produces the polymer - say, polyethylene -as a powder or in the form of chips or flakes, which are often converted (densified) into pellets by extrusion. This resin must be processed to produce the desired product - a molded part, for example. Most processing takes place in the liquid state. The resin must first be melted (we will use the term melt to denote the change from any form of solid to a liquid state, although technically only a crystal has a true melting... 

An alternative method based on a microwave foaming process was described by Zhou, Song, and Parker (2006), which involves converting starch-based raw materials into pellets by extrusion processing, and foaming the extruded pellets by microwave heating. The microwaveable starch pellets are compact for transportation... 

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