Ibuprofen Sustained-Release Dosage Forms

Abstract

Ibuprofen sustained-release tablets, Balkaprofen SR® 600mg (APM Co., Amman, Jordan) were designed to be administered twice daily. These tablets exhibit a bimodal release pattern that is purported to be due to colonic absorption, and consequently a high morning drug plasma concentration may be achieved. This paper reports on single- and multiple-dose regimens of this new formulation compared with commercially available sustained-release twice-daily capsules of ibuprofen (Fenbid Spansules®, 300mg capsules, Smith Kline and Beecham, UK). A 2-way crossover study for each regimen was conducted in 20 healthy male volunteers. In the single-dose study, the volunteers ingested either one 600mg tablet or 2 × 300mg capsules in the morning after having a light breakfast. The plasma ibuprofen concentration-time profile was then monitored for 24 hours. Steady-state was achieved by administering a 600mg dose of either formulation twice daily for 5 days. Blood samples at 8am (predose) on days 2, 3, 4, 5 and 6 of the study were withdrawn for determination of ibuprofen levels, which represented the morning concentration. On day 5, a further 24-hour ibuprofen concentration-time profile was monitored. A washout period of 1 week was allowed after each treatment period. The total area under the plasma concentration-time curve (AUC0–24h) for single and multiple drug administration and the mean concentration at steady-state were not significantly different between these 2 formulations (p > 0.05). However, the fluctuation of the steady-state concentrations was significantly lower for Balkaprofen SR® tablets than for Fenbid® capsules (p < 0.05). Furthermore, the morning steady-state mean plasma concentration after administration of Balkaprofen SR® tablets was significantly higher than that for Fenbid® capsules, being 18.0 and 10.5 mg/L, respectively (p < 0.05). This was interpreted as being a result of higher colonic absorption for Balkaprofen SR® tablets.