Objective: In the present study, thiol-functionalization of psyllium seed polysaccharide (PSY) was cross-linked with thioglycolic acid by esterification in an attempt to reveal the mucoadhesive properties of thiolated psyllium seed polysaccharide (TPSY).
Methods:The crosslinking was carried out by the microwave-assisted method. A simplex centroid design was employed to systematically study the mucoadhesive strength, mucoadhesive retention time and drug release profile. Comparative evaluation of carbopol-based ciprofloxacin hydrochloride (HCl) tablets containing PSY and TPSY was carried out. Acute oral toxicity studies and repeated oral toxicity for TPSY were also conducted.Results: Thiol-functionalization was confirmed by-SH stretch in Fourier Transform infra-red spectra at 2353 cm -1 . Thiolation was observed in thiolated PSY (TPSY) by a change in the surface morphology of psyllium from fibrous to granular and resulted in 82 %swelling in deionized water. TPSY was found to contain 102.35 mmol of thiol groups/g as determined by the Ellman's method. The percent increase in mucoadhesive strength of TPSY was found to be 50.31 % as compared to PSY and 128.30 % as compared to carbopol. The percent increase in mucoadhesive retention time of TPSY was found to be 110 % as compared to PSY and 50 % as compared to carbopol.
Conclusion:Mucoadhesion strength and mucoadhesive retention time were greater of tablets containing a higher amount of TPSY. Further, the acute oral toxicity studies and repeated oral toxicity for TPSY proved it as non-toxic and hence safe for human use.