Fabrication, characterization, thermal stability and nanoassemblies of novel pullulan-aspirin conjugates

Arabian Journal of Chemistry

Muhammad A. Hussain¹  Muhammad Ali¹  Bilal A. Lodhi¹  Muhammad Sher¹  Khawar Abbas¹  Wolfgang Tremel²  Muhammad N. Tahir²  Saima Iqbal² 

[1] Department of Chemistry, University of Sargodha, Sargodha 40100, Pakistan;Institute of Inorganic & Analytical Chemistry, Johannes Guttenberg University, Duesbergweg 10-14, 55128 Mainz, Germany;

关键词: Biopolymers;    Pullulan-aspirin conjugates;    Nanoparticles;    Thermal properties;    Aspirin;    Esterification;   

DOI  :  10.1016/j.arabjc.2013.06.001

来源: DOAJ

【 摘 要 】

Present study deals with homogeneous and one-pot synthesis of novel macromolecular prodrugs (MPDs) of aspirin onto naturally occurring hydrophilic biopolymer pullulan. Pullulan-aspirin conjugates were synthesized by using green carboxylic acid activating reagent 1,1′-carbonyldiimidazole (CDI). The aspirin was first reacted with CDI to prepare aspirin-imidazolide at RT for 24 h which in situ reacted with pre-dissolved pullulan and the reaction preceded further for 24 h at 80 °C under nitrogen. Degree of substitution (DS 0.32–0.40) of aspirin onto pullulan was calculated from 1H NMR spectroscopy. Spectroscopic techniques confirmed the high covalent drug loading and purity. Thermal analysis has revealed that new MPDs of aspirin are thermally more stable than pure aspirin. The activation energy, order and frequency factor of the degradation reactions were calculated using Broido, Friedman and Chang models. The amphiphilic pullulan-aspirin conjugates self-assembled in nanoparticles without further structural modifications at solvent interface in the range of 500–680 nm as examined by transmission electron microscopy. These novel pullulan-aspirin conjugates with masked COOH functional group could be potentially safe prodrugs for the stomach.

【 授权许可】

Unknown