Formulation and Evaluation of Bi-Layer Tablets of Ketorolac Tromethamine

Abstract

The objective of the present study was to develop and evaluate bi-layer tablets of Ketorolac tromethamine, a nonsteroidal antiinflammatory drug with short half-life, that are characterized by initial burst drug release in the stomach and comply with the release requirements of sustained-release products. Each of the proposed bi-layer tablets is composed of an immediate-release layer and a sustained-release layer, anticipating rapid drug release that starts in the stomach to rapidly alleviate the symptoms and continues in the intestine to maintain protracted analgesic effect. Gastro retentive Bi-Layer tablets of Ketorolac Tromethamine were prepared by using hydrophilic polymers with direct compression on floating – matrix technology and evaluated. Ketorolac tromethamine is freely soluble in water, so it is suitable to develop it as gastro retentive bi-layer tablets using hydrophilic polymers. The developed formulation is equivalent to calculated theoretical drug profile in view of its in vitro release. Immediate release layer was prepared by using dry granulation method in which ac-di sol used as a disintigrant for immediate release of drug. Sustained release layer formulated by using HPMC as release retardant, two grades of HPMC that are HPMC K4M and HPMC K100M used to get sustained release profile for 24 hr. Various trial batches are taken to get desired release profile. Ketorolac tromethamine release from the developed floating formulation followed Higuchi model and nonFickian diffusion is found to be the main mechanism of drug release. The manufacturing procedure was found to be reproducible and formulations were stable after one month of stability studies.
 Keywords: FTIR; Gastro retentive bilayer; ketorolac tromethamine; in vitro release; stability; higuchi.