Development of Floating Pellets Using Low-Density Foam Powder Prepared by Extrusion-Spheronization

Abstract

This study’s goal was to develop floating pellets using low-density foam powder prepared by extrusion-spheronization. The model drug used was theophylline. Polypropylene (PP) low-density foam powder provided the system with the properties of low density and buoyancy. The system was prepared by mixing theophylline, microcrystalline cellulose, and PP foam powder together using water as a binder to obtain a damp mass, which was then passed through a sieve to get extrudates. The extrudates were then spheronized to obtain spherical pellets in a spheronizer under optimum conditions. Floating pellets were studied for their size, buoyancy, and drug release with regard to formulation variables. The results revealed that pellets without low-density foam powder had a spherical shape and a smooth surface, whereas pellets with lowdensity foam powder had a rougher surface, which became rougher as the proportion of foam powder increased. An increase in the drug loading and foam powder particle size both increased pellet size. Pellets made with a sufficient amount of foam powder (20% w/w) could float immediately when contacted with dissolution medium (0.1 N HCl) and could remain floating for more than 8 h. The drug release study revealed that increased drug loading, increased foam powder, and decrease pellet size increased the amount of drug released. However, the particle size of foam powder did not significantly affect drug release. According to this study, the optimal formulation of floating pellets exhibited good buoyancy, but still had relatively fast drug release. Further investigations into how to prolong or delay drug release, such as using a polymeric coating, may be required.