PMID- 2766281 OWN - NLM STAT- MEDLINE DCOM- 19891003 LR - 20131121 IS - 0008-5472 (Print) IS - 0008-5472 (Linking) VI - 49 IP - 18 DP - 1989 Sep 15 TI - Controlled delivery of 1,3-bis(2-chloroethyl)-1-nitrosourea from ethylene-vinyl acetate copolymer. PG - 5103-7 AB - 1,3-Bis(2-chloroethyl)-1-nitrosourea (BCNU) has been found to be an effective chemotherapeutic agent against brain tumors. However, because it has a very short half-life in plasma, the exposure of neoplastic cells to BCNU is very brief. The delivery of BCNU may be enhanced by using controlled release polymers. We measured the release of BCNU from ethylene-vinyl acetate copolymer (EVAc) into blood, phosphate buffer, and brain tissue. BCNU-EVAc cylinders that weighed 60 mg were implanted in the peritoneum of rats, and BCNU was detected in blood for 6 days. Studies carried out in vitro showed that BCNU was released from EVAc at a decreasing rate for 195 h. BCNU-EVAc cylinders that weighed 15 mg were implanted either intracranially (i.c.) or i.p. in Fischer 344 rats. Controlled release of BCNU from the i.c. BCNU-EVAc implants was observed over 9 days, with peak drug levels of 49.6 micrograms/g of brain tissue in the implanted hemisphere. The BCNU levels in the contralateral hemisphere and the peripheral circulation were much lower and were detectable for only 1 day. By contrast, peak BCNU levels in the brain from the i.p. BCNU-EVAc implants were 2.7-3.0 micrograms/g for only 12 h, accompanied by peak BCNU levels in blood of 1.0 micrograms/ml tapering over 1 day. These results demonstrate the controlled release of intact BCNU from EVAc in vitro and in vivo. Furthermore, the i.c. implants resulted in localized, prolonged, high levels of the drug in the implanted hemisphere. Hence, the i.c. controlled delivery of BCNU may be more efficacious for the treatment of localized brain tumors. FAU - Yang, M B AU - Yang MB AD - Department of Neurological Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205. FAU - Tamargo, R J AU - Tamargo RJ FAU - Brem, H AU - Brem H LA - eng GR - NS01058-01/NS/NINDS NIH HHS/United States PT - Journal Article PT - Research Support, Non-U.S. Gov't PT - Research Support, U.S. Gov't, P.H.S. PL - United States TA - Cancer Res JT - Cancer research JID - 2984705R RN - 0 (Delayed-Action Preparations) RN - 0 (Drug Implants) RN - 0 (Polyvinyls) RN - 24937-78-8 (ethylenevinylacetate copolymer) RN - U68WG3173Y (Carmustine) SB - IM MH - Animals MH - Brain/metabolism MH - Carmustine/*administration & dosage/blood/pharmacokinetics MH - Delayed-Action Preparations MH - Drug Implants MH - Half-Life MH - Male MH - *Polyvinyls MH - Rats MH - Rats, Inbred F344 EDAT- 1989/09/15 00:00 MHDA- 1989/09/15 00:01 CRDT- 1989/09/15 00:00 PHST- 1989/09/15 00:00 [pubmed] PHST- 1989/09/15 00:01 [medline] PHST- 1989/09/15 00:00 [entrez] PST - ppublish SO - Cancer Res. 1989 Sep 15;49(18):5103-7.