| 摘要 |
The invention relates to an intravaginal drug delivery device for administration to a female mammal of certain 17.beta.-oestradiol precursors at a substantially constant rate for a period of at least three weeks. The 17.beta.-oestradiol precursor is a 17.beta.-oestradiol moiety in which the, or each, hydroxyl group of the 17.beta.-oestradiol moiety is blocked by a blocking group, which blocking group is readily removed from the 17.beta.oestradiol moiety in vivo. The 17.beta.-oestradiol precursor must either have a solubility in liquid silicone of not less than 0.1 mg/100 ml or have a standard k value of not less than 0.1 .mu.g/day/mm. The 17.beta.-oestradiol precursor must also have a solubility in distilled water of not less than 1.mu.g/100 ml. |
