Comparative bioavailability of chlorpropamide tablet and suspension formulations

Area of Science:

• Pharmacokinetics and Drug Bioavailability
• Clinical Pharmacology
• Endocrinology

Background:

• Chlorpropamide is an oral hypoglycemic agent used to manage type 2 diabetes.
• Assessing the bioavailability of different drug formulations is crucial for ensuring therapeutic equivalence.

Purpose of the Study:

• To compare the bioavailability of an oral chlorpropamide tablet formulation against a reference suspension.
• To evaluate the pharmacokinetic and pharmacodynamic profiles of the two chlorpropamide formulations.

Main Methods:

• An open-label, two-way crossover study involving 18 healthy adult males.
• Administration of chlorpropamide 250 mg as a tablet (Diabinese) and suspension, with a 14-day washout period.
• Serial blood sampling for 96 hours to determine chlorpropamide serum concentrations and glucose levels, analyzed using AUC, Cmax, and statistical tests.

Main Results:

• No significant differences were observed in the area under the curve (AUC), peak concentration (Cmax), or time to Cmax between the tablet and suspension.
• Both formulations produced comparable hypoglycemic responses, with similar mean serum glucose concentrations over time.
• The chlorpropamide tablet exhibited a significantly faster absorption rate compared to the suspension.

Conclusions:

• The oral chlorpropamide tablet and reference suspension are bioequivalent.
• Despite a faster absorption rate, the tablet formulation's clinical efficacy in lowering glucose is comparable to the suspension.
• The findings support the interchangeability of the chlorpropamide tablet and suspension for therapeutic use.