Micro-compounding explained

Micro-compounding is the mixing or processing of polymer formulations in the melt on a small scale, typically milliliters. It is popular for research and development because it gives faster, more reliable results with smaller samples and less cost. Its applications include pharmaceutical, biomedical, and nutritional areas.

Design

Micro-compounding is typically performed with a tabletop, twin screw micro-compounder, or micro-extruder with a working volume of 5 or 15 milliliters. With such small volumes, it is difficult to have sufficient mixing in a continuous extruder. Therefore, micro-compounders typically have a batch mode (recirculation) and a conical shape.

The L/D of a continuous twin screw extruder is mimicked in a batch micro-compounder by the recirculation mixing time, which is controlled by a manual valve. With this valve, the recirculation can be interrupted to unload the formulation in either a strand or an injection moulder, a film device or a fiber line. Typical recirculation times are one to three minutes, depending on the ease of dispersive and distributive mixing of the formulation.

Benefits

Micro-compounding can now produce films, fibers, and test samples (rods, rings, tablets) from mixtures as small as 5 ml in less than ten minutes. The small footprint requires less lab space than for a parallel twin screw extruder.^{[1] [2] [3] [4] [5]} One micro-extruder, developed to test whether drug delivery enabled improved bioavailability of poorly soluble drugs or the sustained release of active ingredients show or require sensitive and water destroying invasives.^{[6] [7] [8] [9] [10] [11]}

Notes and References

1. Qizheng Dou, Xiaomin Zhu, Karin Peter, Dan E. Demco, Martin Möller, Claudiu Melian, J. Sol-Gel Sci Technol (2008) 48: 51-60
2. 10.1016/j.polymer.2006.10.013 . Properties and morphology of nanocomposites based on styrenic polymers, Part II: Effects of maleic anhydride units . 2006 . Stretz . H.A. . Paul . D.R. . Polymer . 47 . 26 . 8527–8535 .
3. 10.1002/pc.20392 . Microcompounding of organoclay–ABS/PA6 blend-based nanocomposites . 2008 . Ozkoc . Guralp . Bayram . Goknur . Tiesnitsch . Johan . Polymer Composites . 29 . 4 . 345–356 .
4. 10.1002/pc.20846 . Production of poly(lactic acid)/Organoclay nanocomposite scaffolds by microcompounding and polymer/Particle leaching . 2010 . Ozkoc . Guralp . Kemaloglu . Sebnem . Quaedflieg . Martin . Polymer Composites . 31 . 4 . 674–683 .
5. 10.1002/app.27460 . Effects of microcompounding process parameters on the properties of ABS/Polyamide-6 blends based nanocomposites . 2008 . Özkoç . Güralp . Bayram . Göknur . Quaedflieg . Martin . Journal of Applied Polymer Science . 107 . 5 . 3058–3070 .
6. Markus Thommes, APV Drug Delivery Focus Group Newsletter - 1/2012
7. 2003-05-14 . Ghebre-Sellassie . Isaac . Ghebre-Selassie . Isaac . Martin . Charles E. . Zhang . Feng . DiNunzio . James . Martin . Charles . Pharmaceutical Extrusion Technology . 10.1201/9780203911532. International Journal of Pharmaceutics . 133. 1–2. 1–271 . 978-0-203-91153-2 . www.sciencedirect.com . en-us.
8. Bodor . Nicholas . February 1984 . Techniques of Solubilization of Drugs. Drugs and the Pharmaceutical Sciences Series. Journal of Pharmaceutical Sciences . 73 . 2 . 288 . 10.1002/jps.2600730245 . 0022-3549.
9. Litvinov . V. M. . Guns . S. . Adriaensens . P. . Scholtens . B. J. R. . Quaedflieg . M. P. . Carleer . R. . Van den Mooter . G. . 2012-10-01 . Solid State Solubility of Miconazole in Poly[(ethylene glycol)- g -vinyl alcohol] Using Hot-Melt Extrusion ]. Molecular Pharmaceutics . en . 9 . 10 . 2924–2932 . 10.1021/mp300280k . 22905779 . 1543-8384.
10. Toshiro . Sakai. APV Experts‘ Workshop on Hot Melt Extrusion . 6 November 2012.
11. Sakai . Toshiro . Thommes . Markus . 2014-01-17 . Investigation into mixing capability and solid dispersion preparation using the DSM Xplore Pharma Micro Extruder . Journal of Pharmacy and Pharmacology . en . 66 . 2 . 218–231 . 10.1111/jphp.12085 . 2042-7158.