[Comparison of the pharmacokinetics of a quick-release bezafibrate formulation with a sustained-release formulation. 2. Multiple-dose administration and chronopharmacokinetics].

The pharmacokinetic profile of a 300 mg immediate release formulation (A) was compared to a 400 mg sustained release formulation (B) of the lipid lowering drug bezafibrate (CAS 41859-67-0). Preparation A was applied twice a day whereas B was applied once a day in the evening. The means of Cmax (12.5 micrograms/ml) and AUC (66.8 micrograms/ml.h) for preparation A were considerably higher than for B (Cmax: 6.6 micrograms/ml, AUC: 39.8 micrograms/ml.h), whereas no differences were found regarding Tcav (A: 8.9 h, B: 8.3 h) and PTF (A: 4.6, B; 4.1). An AUC ratio for A/B of 119% (CI90%: 108-132%) was determined after dose correction. For A an AUC/AUEC ratio of 110% was found when comparing multiple versus single-dose application, whereas this ratio with 136% appeared to be considerably higher for B. Slight chronopharmacological effects were found for preparation A, which was applied twice a day in the evening and in the morning. During night-time the AUC was (insignificantly) 12% higher than during day-time, whereas the apparent elimination halflife time was 40% longer at night (p < 0.025), which corresponded to an extended tmax of median 3 h during night-time as compared to 1.75 h at day-time.