Randcastle extruder

Young et al. in 2002 successfully prepared controlled release spherical pellets of theophylline by HME and spheronization process. A Randcastle extruder was used to extrude the mixture of anhydrous theophylline, Eudragit 4135F, microcrystalline cellulose, and PEG 8000. Hot-melt extruded rods were cut into symmetrical pellets and then these pellets were spheronized at an elevated temperature. The dissolution profile of the spherical pellets was dependent on the matrix polymer solubility in the media. 

Most systems function with paste but Young et al. (10) described the use of a process whereby the extrusion was with a hot-melt system, the extrudate cut in a pelletizer (Randcastle RCP-2,0, Randcastle Inc. Cedar Grove. New Jersey, U.S.A.) into cylindrical pellets, which were then spheronized on a conventional spheronizer (Caleva Model 120, AC Compacting LLc, North Brunswick, New Jersey, U.S.A.) heated with a heat gun to 65-70 C while dusting with microcrystalline cellulose (MCC) to prevent agglomeration. The picture of the pellets shown to illustrate the product appears round but the process times of 45 and 80 minutes are considerably longer than those involved with the paste systems. 

Blown film experiments were eonducted using a 5/8 and 24/1 compression single-serew extruder Ifom Randcastle Extrusion Systems, Ine. The blown film tower consisted of A armular die with air feed in the center and on the outer ring. Proeessing temperatures were maintained between 220°C near the feed and 240°... 

---