To develop a sustained-release preparation containing ketorolac tromethamine, two sustained-release pellet formulations were evaluated with a pharmacokinetic study as compared with a conventional commercial tablets (10 ㎎ Tarasyn^(TM), Roche Korea Lt...
To develop a sustained-release preparation containing ketorolac tromethamine, two sustained-release pellet formulations were evaluated with a pharmacokinetic study as compared with a conventional commercial tablets (10 ㎎ Tarasyn^(TM), Roche Korea Ltd.). Two sustained-release formulations were as follows; formulation A was composed of an inner layer containing 75% of drug coated with Eudragit^(TM) RS 100 membrane and an outer layer containing 25% of drug mixed with Eudragit^(TM) NE30D, and formulation B was composed of only an inner layer containing 100% of drug coated with Eudradit^(TM) RS 100 membrane. The dissolution test was performed for two formulations. In case of conventional tablets, 2.5 ㎎ of drug per a dose was administered orally into male Albino rabbit (2.0-2.3 ㎏ of body weight) 3 times at intervals of 4 hours. In case of two sustained formulations, 7.5 ㎎ of drug was administered once orally. Blood samples were withdrawn periodically after the administration, and the blood concentration was determined by HPLC. The conventional tablets showed very high peak-trough fluctuation between administered doses, but two sustained formulations showed less fluctuation. Formulation A with the loading dose showed the time to reach minimum effective concentration (MEC) i.e. the onset time was less than 20 min, while Formulation B had more than 1 hr of the onset time. Formulation A had the more constant plasma level than formulation B. However, formulation B had a time lag, so the plasma level was less than MEC for an initial period of 1 hr. In formulation A, the plasma level was maintained within the therapeutic window (0.3-5 ㎍/㎖) for a long period. Formulation A was thought to be an ideal sustained-release formulation for ketorolac tromethamine oral delivery system.