Pharmacokinetic and bioequivalence study of a telmisartan/S-amlodipine fixed-dose combination (CKD-828) formulation and coadministered telmisartan and S-amlodipine in healthy subjects

PURPOSE: A new fixed-dose combination (FDC) formulation of telmisartan 80 mg and S-amlodipine 5 mg (CKD-828) has been developed to increase convenience (as only one tablet is required per day) and improve treatment compliance. METHODS: The pharmacokinetic characteristics and tolerability of an FDC of telmisartan and S-amlodipine were compared to those after coadministration of the individual agents in this randomized, open-label, single-dose, two-way, four-period, crossover study. To analyze the telmisartan and S-amlodipine plasma concentrations using a validated liquid chromatography–tandem mass spectrometry method, serial blood samples were collected up to 48 hours post-dose for telmisartan and 144 hours post-dose for S-amlodipine, in each period. RESULTS: Forty-eight healthy subjects were enrolled, and 43 completed the study. The mean peak plasma concentration (C(max)) and the area under the plasma concentration–time curve from time 0 to the last measurement (AUC(0–t)) values of telmisartan were 522.29 ng/mL and 2,475.16 ng·h/mL for the FDC, and 540.45 ng/mL and 2,559.57 ng·h/mL for the individual agents concomitantly administered, respectively. The mean C(max) and AUC(0–t) values of S-amlodipine were 2.71 ng/mL and 130.69 ng·h/mL for the FDC, and 2.74 ng/mL and 129.81 ng·h/mL for the individual agents concomitantly administered, respectively. The geometric mean ratio (GMR) and 90% confidence interval (CI) for the telmisartan C(max) and AUC(0–t) (FDC of telmisartan and S-amlodipine/concomitant administration) were 0.8509 (0.7353–0.9846) and 0.9431 (0.8698–1.0226), respectively. The GMR and 90% CI for the S-amlodipine C(max) and AUC(0–t) (FDC/concomitant administration) were 0.9829 (0.9143–1.0567) and 0.9632 (0.8798–1.0546), respectively. As the intrasubject variability of the C(max) for telmisartan administered individually was 42.94%, all 90% CIs of the GMRs fell within the predetermined acceptance range. Both treatments were well tolerated in this study. CONCLUSION: CKD-828 FDC tablets were shown to be bioequivalent to coadministration of the individual agents with the respective strength, in healthy subjects under fasting conditions. There was no significant difference in safety profile between the two treatments.