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Copyright © 2008. KONGPOSH PUBLICATIONS Pvt. Ltd. |
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Abstract: The present study focuses on the development of a controlled release microcapsule of ketorolac tromethamine. Ketorolac tromethamine (KT) is a non-steroidal drug with potent analgesic and anti-inflammatory activity. Microcapsules were fabricated by coacervation phase separation, solvent evaporation technique. Microcapsules were formulated using Eudragit RL100, Eudragit RS100 and Ethyl cellulose, bearing core: polymer ratio of (1:1) and (1:2). The effects of various formulation and process variables on the internal and external particle morphology, micromeritic properties, physical state of the incorporated drug, drug loading and in vitro drug release were studied. The release rate of ketorolac tromethamine microcapsule is mainly governed by core: wall ratio, particle size, and ratio of Eudragit RL and RS 100.
Introduction
Ketorolac tromethamine is a potent nonsteroidal, non-narcotic analgesic with cyclooxygenase inhibitor activity. It is 36 times more potent than phenyl butazone, and twice as that of indomethacin. The plasma half-life of ketorolac ranges from 1.1 to 6.0 h. Its oral bioavailability is estimated to be 80%. Secondly, it causes gastro intestinal disturbances on oral administration. To eliminate these disturbances and to increase patient compliance attempts have been made to formulate a novel drug delivery system of ketorolac tromethamine.
Microcapsules are one of the multiparticulate delivery systems and are prepared to achieve prolonged or controlled drug delivery, improve bioavailability, stability and target drug to specific sites. Microcapsules also offers advantages like limiting fluctuation within therapeutic range, reduced side effects, decreased dosing frequency and improved patient compliance.
Eudragit polymers are the series of acrylate and methacrylate polymers available in different ionic forms. Eudragit RL and Eudragit RS are insoluble in aqueous media but they are permeable and have pH-independent release profiles. The permeability of Eudragit RS and RL in aqueous media is due to the presence of quaternary ammonium groups. The increased permeability of Eudragit RL as compared to Eudragit RS could be accounted to greater proportion of these groups.
The microcapsules were prepared by coacervation phase separation solvent evaporation method using Eudragit RL100, Eudragit RS 100 and ethyl cellulose, respectively. The effects of various formulation and process variables on the internal and external particle morphology, micromeritic properties, physical state of the incorporated drug, drug loading and in vitro drug release were studied.