Comparative Bioavailability of Two Dexamethasone Tablet Formulations in Indonesian Healthy Volunteers

Abstract

Aim:

To compare the bioavailability of two dexamethasone (CAS 50-02-2) tablet formulations–4 mg Dexmethsone^® tablets as test formulation and 4 mg 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 AUC_0–t, AUC_0–∞ and C_max 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 T_max for both formulations was 0.75 h. Plasma elimination half-lives (t_1/2) were 3.44 h (test) and 3.38 h (reference). The point estimates and 90% confidence intervals (CI) for AUC_0–t, AUC_0–∞ 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.

Key words

CAS 50-02-2 - Corticosteroids - Dexamethasone, bioequivalence, pharmacokinetics - Dexmethsone® - Glucocorticoids

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