Production methodologies of polymeric and hydrogel particles for drug delivery applications

Introduction: Polymeric particles are ideal vehicles for controlled delivery applications due to their ability to encapsulate a variety of substances, namely low- and high-molecular mass therapeutics, antigens or DNA. Micro and nano scale spherical materials have been developed as carriers for therapies, using appropriated methodologies, in order to achieve a prolonged and controlled drug administration. Areas covered: This paper reviews the methodologies used for the production of polymeric micro/nanoparticles. Emulsions, phase separation, spray drying, ionic gelation, polyelectrolyte complexation and supercritical fluids precipita- tion are all widely used processes for polymeric micro/nanoencapsulation. This paper also discusses the recent developments and patents reported in this field. Other less conventional methodologies are also described, such as the use of superhydrophobic substrates to produce hydrogel and polymeric particulate biomaterials. Expert opinion: Polymeric drug delivery systems have gained increased impor- tance due to the need for improving the efficiency and versatility of existing ther- apies. This allows the development of innovative concepts that could create more efficient systems, which in turn may address many healthcare needs world- wide. The existing methods to produce polymeric release systems have some critical drawbacks, which compromise the efficiency of these techniques. Improvements and development of new methodologies could be achieved by using multidisciplinary approaches and tools taken from other subjects, including nanotechnologies, biomimetics, tissue engineering, polymer science or microfluidics.

The authors declare no conflict of interest. The authors are grateful for financial support from Portuguese Foundation for Science and Technology (FCT) through the grants SFRH/BD/71395/2010 and SFRH/BPD/489948/2008.