HPMC-salicylate conjugates as macromolecular prodrugs: Design, characterization, and nano-rods formation



original image

Hydroxypropylmethylcellulose (HPMC) is a neutral, nonionic, acid resistant, and hydrolysable in basic medium. Keeping in view these properties, HPMC-salicylic acid conjugates, that is, macromolecular prodrugs were successfully synthesized, purified, and characterized by gel permeation chromatography, thermal analysis (TGA/DTA/DSC) and UV, FTIR, 1H NMR spectroscopic techniques. Chemical attachment (covalent) of the salicylic acid on HPMC and purity of products was verified by spectroscopic analyses. UV spectroscopy has indicated the incorporation of the drug in the conjugates after in vitro release in basic medium. Transmission electron microscopy has shown formation of nano-rods because of amphiphilic nature of products (HPMC-salicylate). All the samples synthesized were found thermally as stable as native HPMC. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]