Poly(vinyl alcohol) gel sphere as GI transit-time controlling dosage form

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 3h to at least 12h after the administration. The usefulness of PVA-GS as a GI transit-time controlling type dosage form was demonstrated.