A novel freeze pelletization technique for preparing matrix pellets

Manufacturers produce pellets using techniques such as balling, extrusion-spheronization, high-speed shear mixing, and drug layering on seeds using coating pans or fluidized-bed equipment. These techniques require expensive equipment, labor-intensive processes, and skilled operators. Freeze pelletization is a novel and simple technique that offers several advantages over other pelletization methods. The pellets are nonporous and spherically shaped with a very narrow size distribution. They are solid at room temperature, so freeze-drying or lyophilization is not required. The technique has fewer process variables than other pelletization methods and works as either a batch or a continuous process. Freeze pelletization has many potential applications for preparing immediate- and controlled-release matrix pellets. Controlled-release pellets are matrix type and do not require additional coating. Pellets made using freeze-pelletization can be subsequently coated with suitable polymers to produce delayed-release and colon-specific formulations. Various excipients can be used in this technique, and formulations can be easily modified to suit a wide range of drug delivery applications.