Amoxicillin: in vitro and pharmacological studies.

Area of Science:

• Pharmacology
• Microbiology
• Drug Development

Background:

• Amoxicillin is a semisynthetic penicillin antibiotic.
• Understanding its pharmacokinetic profile is crucial for clinical application.

Purpose of the Study:

• To evaluate the in vitro activity of amoxicillin.
• To determine the pharmacokinetic properties of amoxicillin following oral administration.

Main Methods:

• In vitro susceptibility testing against common bacterial isolates.
• Oral administration of varying amoxicillin doses (125 mg to 1 g) to healthy volunteers.
• Measurement of peak serum amoxicillin levels and urinary excretion rates.

Main Results:

• Amoxicillin demonstrated in vitro activity against Gram-positive cocci (excluding resistant Staphylococcus aureus) and key Gram-negative bacteria like Proteus mirabilis and Escherichia coli.
• Oral administration resulted in dose-dependent increases in mean peak serum levels, reaching 9.90 mug/ml at 1 g.
• Approximately 70% of the administered amoxicillin was excreted in urine within 6 hours.

Conclusions:

• Amoxicillin exhibits a favorable in vitro activity profile, comparable to ampicillin.
• The drug achieves significantly higher serum concentrations after oral administration compared to ampicillin.
• Its rapid urinary excretion suggests efficient systemic distribution and elimination.