In Situ Intestinal Absorption of Cyclosporine A Solid Dispersion in Rats

Abstract

Effects of concentration of Polyoxyethylene (40) stearate, Na⁺ and P-gp inhibitor on cyclosporin A (CyA-SD) absorption were investigated by in situ circulation method. The results showed that the absorption of CyA increased linearly with its concentration, indicating a passive diffusion process was dominated. CyA absorption decreased with the carrier concentration. The concentration of Na⁺ didn't influence the drug absorbed (P > 0.05). The P-gp inhibitor enhanced the CyA absorption significantly (P < 0.05). The passive diffusion process during the intestinal absorption indicated that the solubility enhancement of CyA is one of the mechanisms for the absorption of this water insoluble drug.

keywords:

• cyclosporine A
• solid dispersion
• polyoxyethylene (40) stearate
• in situ circulation
• absorption behavior