RECTAL ABSORPTION OF ZIDOVUDINE

Rectal absorption of Zidovudine (3'-azido-3'-deoxythymidine, AZT) was investigated in order to determine the feasibility of developing AZT suppositories. Although the small intestine shows a higher absorption rate than the stomach and large intestine in rats, considerable absorption of AZT was observed from the lower large intestine (8 cm above the anus). A sustained-release suppository was prepared by direct compression of hydroxypropyl cellulose (HPC) with AZT. During in vivo experiments in rats, this suppository (10 mg or 37.5-mu-mol AZT/kg) maintained constant plasma levels above 1-mu-M for more than 6 h. The results suggest that suppositories can prove useful as an alternative dosage form of AZT administration.