Main objective of the present study was to formulate and evaluate colon specific tablets of Ketorolac tromethamine using natural
gums in view to develop delayed release dosage form which can stay in colon for prolonged period of time for continuous release of
drug, maximize bioavailability of Ketorolac tromethamine and increase patient compliance. For the present study, natural polymers
like chitosan, guar gum, karaya gum and xanthan gum(20%,30%,40%). Matrix tablets of Ketorolac tromethamine with natural gums
were prepared by wet granulation method and then coated with combination of pH sensitive polymers (Eudragit L100 and Eudragit
S100) in 1:1 proportion. IR spectra of drug, excipients and dosage forms reveals that there was no interaction and found to be
compatible with each other. Prepared uncoated and coated tablets were characterized for physical parameters, drug content and in vitro
drug release studies. In vitro drug release studies was carried out in 0.1 N HCl (2 hrs) then in pH 7.4 phosphate buffer (3 hrs) and then
continued in pH 6.8 phosphate buffer up to 24 hr. The best formulation (F11) containing karaya gum (30%) showed 95.80% drug
release up to 24 hr. The dissolution of Ketorolac tromethamine tablets followed first order kinetics. The tablets showed no significant
change either in physical appearance or in dissolution pattern after storing at 400
C / 75% RH for three months.