Study On High-Level Drug Loading SR Pellets Prepared By Extrusion-Spheronization Technique

Extrusion-Spheronization is an important method to prepare pellets in industrial pharmaceutics fields. Compared with other drug-loading methods such as rotary coater pelletization and fluid-bed pelletization . Extrusion-spheronization possesses its high drug-loading advantage (more than 80%) especially. It has been approved to be an excellent technique to prepare the pellets with high drug-loading.Guaifenesin(GFN) has been used as the traditional expectorant in the clinical therapeutics. Its expectorant mechanism is based on increasing the excreta of bronchia with irritating gastrointestinal mucus and enhancing the output of respiratory tract fluid by reducing adhesivenesss and surface tension, facilitating the removal of viscous mucus. Conventional dosage forms of Guaifenesin with 3-4 administrations per day have been used for long time due to its short t_1/2, and GFN sustained release dosage forms have not been reported yet in China.FDA approved the Guaifenesin tablets( Mucinex?, 600mg ) with 12hr sustained release in 2002,It was got high evaluated in clinical effects.In this study, about 80% drug loading matrix pellets of Guaifenesin prepared by extrusion-spheronization technology. The pellet quality was evaluated in terms of sphericity, friability and yields. The results showed that extrusion speed, spheronization speed and spheronization time were all important, and optimized technical parameters of 80% Guaifenesin pellets were as following:e.g. 75rpm of extrusion speed, 800rpm of spheronization speed and 4min of spheronization time.Ethyl cellulose aqueous dispersion (Surelease(?)) and Acrylic acid resin aqueous dispersion (Eudragit(?) NE30D) were chosen as the film coating materials to prepare the Guaifenesin sustained release pellets with fluid-bed coating technology. Surelease was decided to be the final coating material for the reason of obvious "lag time" of Eudragit(?)NE30D which caused the drug release content was far less than the designed level- 25% at the first hour in Vitro.