Terutaka Takahashi

Effect of food on the bioavailability of cyclandelate from commercial capsules

The bioavailability of five capsules of cyclandelate that are commercially available in Japan was determined in ten healthy volunteers by measuring mandelic acid (a main metabolite of cyclandelate) excreted in the urine. Bioinequivalence among the five capsules was demonstrated. The relative cumulative excretion of mandelic acid of the most poorly bioavailable capsule was 38% of the most highly bioavailable capsule. The effect of food on the bioavailability of these two capsules was investigated by use of two different kinds of food, one containing fat and one containing high carbohydrates but very low fat. The bioavailability of the two capsules was increased when subjects consumed both types of food before drug administration, although there was a greater effect on bioavailability with food containing fat. This suggests that the absorption of cyclandelate was incomplete in fasting subjects, even from the capsule with the highest bioavailability. Bioinequivalence between the two capsules remained after postprandial drug administration.

Suitable Size of Preparations to Evaluate the Bioavailability of Enteric-Coated Preparations by the Use of Gastric-Acidity-Controlled Rabbits

The limiting size of enteric-coated preparations for which it is possible to evaluate the bioavailability by using gastric-acidity-controlled rabbits (GAC-rabbits) was investigated. Entericcoated preparations with different diameters were administered to GAC-rabbits, and drug bioavailability from each preparation was evaluated. In the case of enteric-coated granules, there was no problem in evaluating the bioavailability. However, in the case of enteric-coated tablets, the maximum size for which it was possible to evaluate the bioavailability was 4.1mm in diameter. The results indicate that the use of GAC-rabbits in bioavailability studies of enteric-coated preparations is restricted by the size of the preparations.