Aim: To compare the bioavailability of two dexamethasone (CAS 50-02-2) tablet formulations - 4 mg Dexmethsone® tablets as test formulation and 4mg tablets of the originator product as reference formulation. Methods: The study was conducted according to an open-label, randomized two-way crossover design with a one-week washout period. Twenty-four volunteers received a single dose of two tablets of the two different dexamethasone formulations. Blood samples for pharmacokinetic profiling were taken up to 24 h after drug administration in fasting condition. Plasma concentrations of dexamethasone were determined with a validated HPLC method using an ultraviolet detector. Pharmacokinetic parameters were calculated from observed plasma concentration-time profiles. Result: The mean AUC0-t, AUC0-∞ and Cmax were 501.61 ng·h/ml, 518.88 ng·h/ml and 98.02 ng/ml, respectively for the test formulation and 507.10 ng·h/ml, 525.20 ng·h/ml and 97.82 ng/ml, respectively, for the reference formulation. The median Tmax for both formulations was 0.75 h. Plasma elimination half-lives (t1/2) were 3.44 h (test) and 3.38 h (reference). The point estimates and 90% confidence intervals (CI) for AUC0-t, AUC0-∞ and C max were 98.92% (94.62-103.41%), 98.80% (94.51-103.28%) and 100.20% (91.43-109.81%), respectively, satisfying the bioequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration guidelines. Conclusion: These results indicate that the two formulations of dexamethasone are bioequivalent and thus may be prescribed interchangeably.
- CAS 50-02-2
- Dexamethasone, bioequivalence, pharmacokinetics