Porous microspheres: Synthesis, characterisation and applications in pharmaceutical & medical fields

Porous microspheres have interconnective external and internal pores leading to very low mass density and enormous specific surface area, enabling them to have excellent adsorption capabilities. Due to this uniqueness over traditional microsphere, they find extensive pharmaceutical applications. Porous microspheres are very promising for gastro retentive drug delivery, alveoli targeted drug delivery, high-speed chromatography, development of tissue regeneration scaffolds and as carrier of biopharmaceuticals. Pore structure and porosity are the main factors that govern their applications. There are different well-established methods for their synthesis, like seed swelling, solvent evaporation, polymerization, spray drying and phase separation. But most of the methods are time consuming and consists of numbers of complicated steps. The size, shape and pore structure of the particles depend on many experimental variables like temperature, pH, stirring speed, type and concentration of porogen, polymer and its concentration. Thus, synthesis of porous microparticle with predefined porosity is really challenging.