Maximal bioavailability of digoxin from tablets and oral solution in steady state

Area of Science:

• Pharmacokinetics
• Drug Formulation
• Gastrointestinal Absorption

Background:

• Digoxin is a crucial medication for heart conditions.
• Understanding digoxin bioavailability from different oral formulations is essential for therapeutic efficacy.
• Lanoxin tablets are a common oral dosage form of digoxin.

Purpose of the Study:

• To compare the pharmacokinetic profiles of digoxin from Lanoxin tablets versus an oral solution.
• To evaluate the bioavailability and absorption characteristics of digoxin in different oral formulations.
• To investigate the influence of formulation on digoxin absorption.

Main Methods:

• Comparative pharmacokinetic study in healthy subjects.
• Measurement of plasma digoxin concentrations over 24 hours.
• Quantification of urinary digoxin excretion.
• Analysis of area under the plasma concentration-time curve (AUC).

Main Results:

• Similar steady-state plasma digoxin levels were observed between tablets and oral solution.
• Comparable 24-hour plasma concentration curves (AUC) for both formulations.
• Urinary excretion of digoxin was similar, indicating equivalent systemic absorption.
• Digoxin absorption was 78% from tablets and 76% from the oral solution.
• Rapid dissolution of Lanoxin tablets in intestinal fluids contributes to high bioavailability.

Conclusions:

• Lanoxin tablets demonstrate comparable digoxin absorption and bioavailability to an oral solution.
• The rapid dissolution rate of Lanoxin tablets ensures efficient digoxin absorption.
• Formulation plays a key role in achieving high digoxin bioavailability from oral dosage forms.