In vitro sustained release of novel natriuretic peptide from solvent evaporation delivery system

• Main Author: Ong, Crystal Li En
• Other Authors: Subramanian Venkatraman
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering::Materials::Nanostructured materials
• Online Access: http://hdl.handle.net/10356/66505
• Institution: Nanyang Technological University

Solvent evaporation technique has been widely studied and is an established method for producing biodegradable Nano or micro particles for pharmaceutical applications. Biodegradable polymers such as poly (lactic-co-glycolic acid) (PLGA) is commonly used as drug carriers due to its biodegradability without any toxic by products, which can be tailored for use as sustained drug delivery systems. However, the hydrophobic nature of PLGA makes it difficult to entrap hydrophilic drugs such as peptides to a good extent. This could pose problems for sustained drug delivery due to insufficient amount of drug available to work therapeutically or short release time frames which could be inefficacious. Hence in this project, the effects of additives on drug loading and loading efficiency are investigated. Studies were conducted based on two types of additives added to the polymer and drug solution during fabrication via solvent evaporation technique. The additives are PEG (5000)-PCL (10000) and Pluronic F127, of which both are amphiphilic in nature. The idea was to use this property to improve hydrophilic drug encapsulation into the hydrophobic polymer. One of the fabrication conditions, the oil phase (PLGA in DCM) to aqueous phase (drug in 1% PVA) ratio, was also changed such that both Nano and micro particles were produced. The effects of the additives on the size of the particles were also studied. Release study results show that Pluronic F127 had a better effect in improving the drug loading and loading efficiency for micro particles. There was an almost three fold improvement in loading efficiency compared to adding F127 to the nanoparticles, due to an increase in the overall hydrophilicity of the particle. The increase in hydrophilicity decreased the solubility of the polymer in the organic solvent and facilitated faster polymer solidification, which was able to encapsulate more drugs.