Abstract
Poly(vinyl alcohol) gel sphere(PVA -GS)was prepared and the GI transit-time was examined in rats following the oral administration by monitoring unabsorbable phenol red contained in the dosage form. While more than 90% of the aqueous solution was transferred to the large intestine 6 h after the administration, about 40% of PVA-GS still remained in the ileum. Thus, PVA-GS can provide drugs prolonged residence in the small intestine, the major site of drug absorption. The prolonged plasma concentration-time profile of cephalexin was observed following oral administration of the antibiotic as the PVA-GS dosage form. Although the maximum concentration became the half of the aqueous solution, the constant plasma level was maintained from 3 h to at least 12 h after the administration. The usefulness of PVA-GS as a GI transit-time controlling type dosage form was demonstrated.
