N. N. Mallikarjuna

Synthesis and characterization of some organopolyphosphazenes and their controlled-release characteristics

Two new organopolyphosphazenes, viz., poly[bis(3-methoxy benzyloxy) phosphazene] (POP-1) and poly[bis(4-fluoro-4′-oxybenzophenone)]phosphazene (POP-2), have been prepared by replacing chlorine atoms of dichloropolyphosphazene with 3-methoxy benzylalcohol and 4-fluoro-4′-hydroxy-benzophenone. The polymers have been characterized by Fourier tranform infrared spectroscopy (FT-IR), 1H- and 31P-nuclear magnetic resonance (NMR) spectra and thermogravimetric (TGA) analyses. The polymers have been developed as microspheres to study their controlled-release characteristics for indomethacin, an anti-inflammatory drug. Drug-loaded microspheres have been tested for in vitro release in pH 7.4 buffer media. FT-IR, 1H- and 31P-NMR data confirmed the formation of polyorganophosphazenes substituted with 3-methoxy benzylalcohol and 4-fluoro-4′-hydroxy-benzophenone. In vitro drug-release studies have indicated sustained and controlled release of indomethacin through POP microspheres.

COLUMNS: Polymeric Membranes

Polymeric membrane–based fuel cell technology has grown as a full fledged technology in recent years due to its inherent advantages to satisfy the power needs by replacing the conventional energy sources. The technology is pollution-free and converts hydrogen fuel into electricity. Membranes are the heart of the fuel cell technology. The present column addresses some advances taken place on Polymer Electrolyte Membrane Fuel Cells (PEMFC). Fuel cells are the electrochemical devices that convert chemical energy of the reactants into electricity and heat with high efficiency. High efficiency makes fuel cells an attractive option for a wide range of applications, including road vehicle power sources and consumer electronic products.