Efficacy of chenodeoxycholic acid and ursodeoxycholic acid for lowering cholesterol saturation index of gallbladder in patients with a sphincterotomy

Bioequivalence of a new liquid formulation of ursodeoxycholic acid (Ursofalk suspension) and Ursofalk capsules measured by plasma pharmacokinetics and biliary enrichment

BACKGROUND

Ursodeoxycholic acid is an approved therapy for hepatobiliary disorders but in infants and children compliance is compromised because it is formulated exclusively as capsules, or tablets.

AIM

To determine the pharmacokinetics and bioequivalence of a new liquid formulation of ursodeoxycholic acid (Ursofalk suspension) with a standard capsule (Ursofalk) in a randomized, unblinded, crossover designed study of 24 healthy adults.

METHODS

Equivalence was based on single bolus oral plasma pharmacokinetics and biliary ursodeoxycholic acid enrichments after repeat doses. Biliary bile acid composition and hydrophobicity index were also compared. Ursodeoxycholic acid was measured in duodenal bile by high-performance liquid chromatography and in plasma by mass spectrometry.

RESULTS

The mean percentage biliary ursodeoxycholic acid enrichment after administration of the suspension was not significantly different from that obtained with capsules (44.2 +/- 11.7% vs. 46.9 +/- 10.2%, respectively). The equivalence ratio was 0.94 (95% CI: 0.8-1.1), establishing bioequivalence between suspension and capsules. Both formulations reduced the biliary hydrophobicity index and no differences in bile acid composition were observed between formulations. The plasma pharmacokinetics of both formulations was similar and the tolerability of the suspension was excellent.

CONCLUSIONS

A new liquid formulation of ursodeoxycholic acid suitable for paediatric patients is pharmacologically bioequivalent to capsules when given as single, or repeated oral doses.

Prospective, multicenter study on value of computerized tomography (CT) in gallstone disease in predicting response to bile acid therapy

The aim of the study was to assess the value of quantitative attenuation values (Hounsfield units) and of gallstone pattern by computerized tomography in predicting response to bile acid therapy. We carried out a prospective study in a multicenter setting on 90 consecutive outpatients with radiolucent gallstones. All received bile acid therapy (UDCA 10 mg/kg/day or UDCA + CDCA 5 mg/kg/day of each) up to two years. Hounsfield units for gallstones were recorded using standardized criteria and six categories of patterns were defined: hypodense, isodense, homogenously dense, laminated, rimmed and speckled. We assessed gallstone dissolution rate (percent reduction in volume), response to therapy (> 25% reduction in volume), and final outcome of therapy. Eighty-one percent of patients with hypodense/isodense and all four patients with speckled stone pattern responded to therapy, whereas none of the 10 patients with laminated/rimmed and only 45% of patients with homogenously dense stone pattern did. Complete dissolution was achieved by 68%, 50%, 35%, 0% of the hypodense/isodense, speckled, homogenously dense, rimmed/laminated gallstones, respectively. The use of Hounsfield units did not show an advantage over gallstone pattern for predicting either response or final outcome to bile acid therapy. We conclude that computerized tomography analysis of gallstones is of value in predicting response to bile acid therapy and that gallstone pattern alone predicts response in most cases without the need for quantitative assessment.