Study on fabrication of composite hydrogel/hydrophobic polymer microparticle for drug release

• Main Author: Tan, Sherwyn Keith Yew Jin.
• Other Authors: Loo Say Chye Joachim
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Materials::Biomaterials
• Online Access: http://hdl.handle.net/10356/52083
• Institution: Nanyang Technological University

Recently, much emphasis has been placed on the creation of drug delivery systems that are able to encapsulate and deliver water-soluble drugs in vivo to treat a wide variety of diseases. Hydrogel-hydrophobic polymer composite microparticles have been developed to encapsulate water-soluble drugs due to the improved encapsulation efficiency and controlled release obtained from these drug delivery systems. In this project, alginate-poly(lactic-co-glycolic acid) microparticles (Alg- PLGA MP) and alginate-poly(L-lactic acid) microparticles (Alg-PLLA MP) were fabricated based on the water-in-oil-in-water double emulsion solvent evaporation technique. The alginate materials were encapsulated within the hollow of the hardened PLGA and PLLA shells, thereby indicating that the ionotropic gelation of alginate and the solvent evaporation process took place concurrently. Subsequently, three process parameters were varied, which involved the addition of an osmolyte and a water-soluble drug in the internal water phase, and varying the volume of the external water phase. These fabricated microparticles were analysed via scanning electron microscopy and Fourier transform infra-red spectroscopy in order to observe the changes in the formation and morphology of the alginate components. It was observed that layered alginate structures formed when there was a zero osmotic pressure difference between the internal and external water phases of the double emulsion system. However, alginate ball-like core structures were prevalent after the addition of the water-soluble drug and a decrease in the volume of the external water phase. It is hoped that this study would lead to a better understanding on how certain process parameters affect the formation and morphology of the alginate material, thus allowing future improvements to be made to this drug delivery system.