Thiol functionalization of flaxseed mucilage: Preparation, characterization and evaluation as mucoadhesive polymer.

The aim of present study is to browse mucoadhesive potential of flaxseed mucilage after thiol functionalization. Thiol-derivatization of flaxseed mucilage (FSM) polysaccharide was obtained by esterification with thioglycolic acid. Thiolation of FSM was confirmed by -SH stretch in FTIR spectra at 2549.01 cm-1. Thiolated flaxseed mucilage (TFSM) was distinguished by XRD, DSC, NMR & SEM analysis. TFSM was found to contain 325.6 mM of thiol groups/g as determined by Ellman's method. The mucoadhesive property of drug loaded TFSM pellets, carried out by using chicken buccal pouch membrane, displayed greater ex-vivo bioadhesion time as compared to FSM. This improvement in mucoadhesion property of TFSM over FSM can be attributed to the formation of disulphide bond between mucus and thiolated mucilage. Further, the in-vitro dissolution study conducted in phosphate buffer (pH 6.8) provided release of diclofenac sodium for a prolonged period of 12 h for TFSM pellets by anomalous transport mechanism of drug release following zero order model of release kinetics.