Bioavailability of atenolol formulations

Area of Science:

• Pharmacokinetics
• Drug Formulation
• Clinical Pharmacology

Background:

• Atenolol is a widely prescribed beta-blocker for cardiovascular conditions.
• Understanding bioavailability differences between formulations is crucial for therapeutic efficacy.
• Comparative studies ensure consistent drug delivery and patient outcomes.

Purpose of the Study:

• To compare the bioavailability of two atenolol tablet formulations (sales and clinical trial) against an oral solution.
• To assess pharmacokinetic parameters including peak blood concentrations, area under the curve (AUC), and elimination half-life.
• To evaluate the safety and tolerability of different atenolol formulations.

Main Methods:

• A randomized, three-way crossover study involving 12 healthy adult male volunteers.
• Administration of a 100 mg oral dose of each atenolol formulation on separate occasions.
• Bioavailability assessment based on whole blood and urine atenolol concentrations.

Main Results:

• Atenolol blood levels peaked around 3 hours post-dose, with significant inter-individual variability (four-fold difference).
• The UK sales tablet demonstrated significantly higher AUC and mean peak blood concentrations compared to the oral solution.
• Both tablet formulations showed similar absorption and excretion profiles, with average elimination half-lives between 6-7 hours.
• No adverse reactions were reported, indicating good tolerability across all formulations.

Conclusions:

• Atenolol tablet formulations, particularly the UK sales tablet, exhibit enhanced bioavailability compared to the oral solution.
• Despite formulation differences, atenolol demonstrates consistent pharmacokinetic profiles and good safety.
• These findings support the interchangeability of formulations when bioavailability is considered.