[A device for prolonged releasing of anticancer drug--bleomycin (author's transl)].

We reported a new dosage-form for intracranial administration which releases Bleomycin (BLM) for more than twenty days. The new dosage-form is a tablet which is a compressed form of lactose and BLM, further capsulized by ethylcellulose or Eudragit retard S. Two kinds of tablets were prepared: early-releasing type and late-releasing type, which differ with regard to ingredients and thickness of the capsule. In a buffer solution at 37 degrees C, the early-release tablet released BLM for 7 days and the late-type for between 20 and 30 days. The late-releasing type was used in the following experiments. BLM tablets were implanted into femoral muscle and peritoneal cavity of rats, and the residual BLM content in each tablet was measured after various periods. In femoral muscle, the half life of BLM in the tablet was 13 days and BLM was no longer found in the tablet after 30 days. In peritoneal cavity, the half life of BLM in the tablet was 15 days and 20% of the BLM still remained in the tablet after 30 days. The half life was 11 days in tablets implanted into the cerebrum of dogs. Following implantation of 4 tablets (12mg. p) into the cerebrum of dogs, CSF levels of BLM could be measured till the 20th day. Histological studies on dog cerebrum revealed a thin capsule consisting of collagenous fibers surrounding the tablet and small round cells or gliosis were seen around the capsule.