Sustained release of progesterone and estradiol on adult female rats by ceramic delivery devices.

The present study was undertaken with the purpose of investigating the effectiveness of CDS implants to deliver progesterone (P) and estradiol (E) in a sustained levels for long duration using adult female rats as a model. A total of 128 CDS implants, each having a final fired density of 1.88 +/- S.D. 0.17 g/cm3, were fabricated by using standard laboratory procedure. A total of 80 CD-female rats were randomly divided into five equal groups. Rats in groups II, III and IV and V were implanted with capsules containing 100 mg P, 5 mg E, 100 mg P plus 5 mg E, and 100 mg P plus 10 mg E. Group I animals were left without implants and served as controls. At the end of 2,4, 6 and 10 weeks postimplantation four rats from each group were euthanized and the reproductive organs were collected and the CDS devices were retrieved. The total amount of P and E left within the devices was determined spectrophotometrically. Data obtained indicates that a sustained rather constant release of P and E during the entire investigation. Steroid delivery rates from the CDS implants in groups II and III and IV differed significantly (P,0.05) for the 10 week period of the experiment. The results show that the rate of E released from the CDS implants was directly proportional to the amount of steroid placed initially in the reservoir.(ABSTRACT TRUNCATED AT 250 WORDS)