Pharmacokinetics of ketorolac tromethamine compression-coated tablets for colon delivery

Present research efforts are focused in developing compression-coated ketorolac tromethamine tablets to improve the drug levels in colon by retarding the drug release in the stomach and small intestine. To achieve this objective, core tablets containing ketorolac tromethamine were prepared by direct compression and compression coated with sodium alginate. The developed tablets were evaluated for physical properties, in vitro drug release, X-ray imaging, and pharmacokinetic studies in human volunteers. Based on the in vitro drug release study, the optimized formulation showed very little drug release (6.75 +/- 0.49%) in the initial lag period of 5 h, followed by progressive release up to 97.47 +/- 0.93 % within 24 h. The X-ray imaging of tablets in human volunteers showed that the tablets reached the colon without disintegrating in the upper gastrointestinal tract. From the pharmacokinetic study, the C-max of colon-targeted tablets was 3,486.70 ng/ml at T-max 10 h, whereas in the case of immediate-release tablets, the C-max of 4,506.31 ng/ml at T-max 2 h signifies the ability of compression-coated tablets to target the colon. In conclusion, compression-coated tablets are suitable to deliver ketorolac tromethamine to the colon.