Bioequivalence study of cilostazol 20% powder 0.5 g and cilostazol 100 mg tablets in healthy adult male subjects

Cilostazol 20% powder is an orally disintegrated formulation that was newly developed for easier swallowing by patients with swallowing disorders that make it difficult for them to take cilostazol tablets with water. The bioequivalence of cilostazol 20% powder 0.5 g ingested with or without water and one cilostazol 100 mg tablet ingested with water was evaluated in 33 healthy adult male subjects in an open-label, randomized, 2-formulation, 2-treatment, 3-period crossover study. The differences (powder without water-tablet, point estimates) in the mean log-transformed AUC_60h and C_max values between the powder without water and the tablet were respectively log (0.93) and log (1.05), with respective 90% confidence intervals of log (0.87) to log (0.99) and log(O.96) to log(1.14). The differences (powder with water-tablet, point estimates) in the mean log-transformed AUC_60h and C_max values between the powder with water and the tablet were respectively log(0.87) and log(1.02), with respective 90% confidence intervals of log (0.81) to log (0.92) and log (0.94) to log (1.11). All values were within the range of the judgment criteria of log (0.8) to log (1.25) specified in the guideline for bioequivalence studies. Based on the above results, cilostazol 20% powder 0.5 g, when administered either with or without water, was judged to be bioequivalent to one cilostazol 100 mg tablet. All adverse events observed in all groups were mild in severity and were resolved without treatment. No deaths or other serious adverse events or clinically significant adverse events occurred.