Pharmacokinetics and safety of single and multiple doses of Asacol tablets in Japanese healthy volunteers

Introduction The pharmacokinetics and safety of Asacol ® (Tillotts Pharma AG, Ziefen, Switzerland), which has been used worldwide to treat ulcerative colitis and Crohn’s disease, were studied in Japanese healthy male volunteers. Methods Drug plasma concentrations and urinary and fecal excretions after a single dose (400–4800 mg) and multiple doses (3600 mg/day for 7 days) were investigated. Results All adverse events were “not serious.” The peak plasma concentration (C max ) was reached at 12.3–18.0 hours after a single dose, and the C max and area under the plasma concentration-time curve (AUC) of mesalazine and its N-acetyl metabolite were proportional to the doses. The C max and AUC in non-Japanese subjects reported in the literature were closely correlated to findings in Japanese subjects, and external excretions were also similar in the Japanese and non-Japanese subjects. Conclusions Asacol was safe and well tolerated in this Japanese population, and the non-Japanese clinical data could be extrapolated to the Japanese population.