OBJECTIVE: To conduct the in vitro test on drug release of rifampin encapsulated in a carrier made of porous phosphate glass ceramics and to analyze main factors which affect the drug release rate. METHODS: A certain quantitative of rifampin was sealed in a hollow cylindrical capsule which consisted of chopped calcium phosphate crystal fiber obtained from glass crystallization. The rifampin concentration was measured in the simulated physiological solution in which the capsule soaked. RESULTS: Rifampin could be released in a constant rate from the porous glass ceramic carrier in a long time. The release rate was dependent on the size of crystal fiber and the wall thickness of the capsule. CONCLUSION: This kind of calcium phosphate glass ceramics can be a candidate of the carrier materials used as long term drug therapy after osteotomy surgery.
Chitosan is a kind of biological material with good histocompatibility and gradual biodegradability in vivo. It has no toxicity or side-effect. For its gradual degradation, chitosan and adriamycin were mixed and formed drug delivery system (DDS). The release test of DDS and exudant of DDS in inhibiting OS-116 were examined in vitro. The results were as following: the DDS could release adriamycin in slow and stable way. The SO-116 inhidition rate of the exudant of the DDS on the 1st, 20th, 40th and 60th day was 58.11%, 36.48%, 24.32% and 21.62% respectively. It was concluded that the drug delivery system was a slow release system. It could maintain the concentration of adriamycin in a certain level. It was also suggested that the chitosan was a good carrier for slow release of chemotherapeutic drug in local therapy for postoperative treatment of bone tumor.