Formulation and pharmacokinetics of colon-specific double-compression coated mini-tablets: Chronopharmaceutical delivery of ketorolac tromethamine.

The present study is designed and significantly planned to study the effect of double-compression coating on core mini-tablets to attain the chronopharmaceutical delivery of ketorolac tromethamine to colon. Double-compression coated tablets were prepared based on time-controlled hydroxypropyl methylcellulose K100M inner compression coat and pH-sensitive Eudragit S100 outer compression coat. From the in vitro drug release studies, F6 tablets was considered as the optimized formulation, which retarded the drug release in stomach and small intestine (3.51 ± 0.15% in 5h) and progressively released to colon (99.82 ± 0.69% in 24h). The release process followed supercase-II transport with zero order release kinetics. Similarity factor calculated from stability studies was found to be 84.73. From the pharmacokinetic evaluation, the immediate release core mini-tablets reached peak plasma concentration (Cmax of 4532.68 ± 28.14 ng/ml) at 2h Tmax and colon targeted tablets showed Cmax=3782.29 ± 17.83 ng/ml at 12h Tmax. The area under the curve and mean resident time of core mini-tablets were found to be 11,278.26 ± 132.67 ng-h/ml and 3.68 h respectively while 17,324.48 ± 56.32 ng-h/ml and 10.39 h for compression coated tablets. Hence the development of double-compression coated tablets is a promising way to gain the chronopharmaceutical delivery of ketorolac tromethamine to colon.