Study on in vivo release of levonorgestrel-containing silicon capsule

The in vivo release rate of levonorgestrel-containing silicon capsule (in vitro releasing rate: 6 micrograms/d) placed in rabbits was determined. The results showed that the average release per year was 8.32 micrograms with r being 0.96000. The release pattern of the levonorgestrel-containing silicon capsule system was proved to be zero-order release. Our study provided some experimental data for clinical use of the system for birth control.