Improved intestinal absorption of an enteric-coated sodium ursodeoxycholate formulation

Area of Science:

• Pharmacology
• Drug Delivery Systems
• Gastroenterology

Background:

• Ursodeoxycholic acid (UDCA) is a therapeutic bile acid.
• Optimizing UDCA oral bioavailability is crucial for its efficacy.
• Enteric coating can modify drug release and absorption.

Purpose of the Study:

• To evaluate the pharmacokinetic profile of a novel enteric-coated sodium ursodeoxycholate formulation.
• To compare the bioavailability of enteric-coated sodium ursodeoxycholate with conventional formulations of UDCA and its salts.
• To assess the absorption of glycoursodeoxycholate (GUDCA) from enteric-coated and conventional formulations.

Main Methods:

• Preparation and administration of enteric-coated sodium ursodeoxycholate and sodium glycoursodeoxycholate to human subjects.
• Measurement of serum bile acid levels using enzyme immunoassay.
• Comparison of Area Under the Curve (AUC) values for different formulations and administration routes in humans and bile fistula rats.

Main Results:

• Enteric-coated sodium ursodeoxycholate showed significantly higher serum levels (AUC) compared to ursodeoxycholic acid and sodium ursodeoxycholate in gelatin capsules.
• No significant differences in serum levels were observed for glycoursodeoxycholate when administered in enteric-coated or conventional forms.
• In rats, the intraduodenal to intravenous recovery ratio for sodium ursodeoxycholate solution was higher than for ursodeoxycholic acid suspension.

Conclusions:

• Enteric coating enhances the oral bioavailability of sodium ursodeoxycholate.
• The formulation protects the drug from gastric acidity, allowing release in the intestine.
• Glycoursodeoxycholate absorption appears unaffected by enteric coating under these conditions.