Melt spheronization

Young, C. R., Dietzsch, C., and McGinity, J. W. (2005), Compression of controlled-release pellets produced by a hot-melt extrusion and spheronization process, Pharm. Dev. Technol., 10,133-139. 

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. 

The methionine and lysine monohydrochloride cores are produced by a melt-binder extrusion spheronization process. Particle diameters are ranging from 1.5 to 2.5 mm. The coating is composed of hydrophobic substances and a pH-sensitive polymer which is able to dissolve or swell in the acidic abomasal medium. The cores are coated in a fluid-bed coater using a solvent-free process (Fig. 3). 

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. 

S-SNEDDS complement the liquid SNEDDS and overcome the limitations that include poor stability and portability, plausible interactions of the formulation component with the capsule shell, and evaporation of the cosolvent leading to precipitation of the drug associated with the liquid SNEDDS. Reduction in the volume of administration, due to the solid state of S-SNEDDS, enhances precise dosing. Various techniques, such as adsorption on the inert carriers, spray drying, extrusion—spheronization, and melt granulation, have been explored for the formulation of S-SNEDDS (Tan et al., 2013). S-SNEDDS utilized for enhancing the oral bioavaUability of drug candidates are listed in Table 4.4. 

These can be prepared by techniques like wet granulation, extrusion—spheronization, and hot melt extmsion, as illustrated in Figure 4.8. Solid self-nanoemulsifying pellets are documented to possess several advantages, such as flexibility of manufacturing, reduced intra- and/or intersubject variation in plasma profiles, and minimal G1 irritation (Serratoni et al., 2007). 

Journal of Microencapsulation 20, No.5, Sept.-0ct.2003, p.613-25 PROPERTIES OF DRUG-CONTAINING SPHERICAL PELLETS PRODUCED BY A HOT-MELT EXTRUSION AND SPHERONIZATION PROCESS... 

---