[Transvaginal absorption of an oleic solution of progesterone (Gestone) in fertile women].

Transvaginal absorption of a progesterone (P) oleic formulation, commercially available for intramuscular administration (Gestone, Amsa, Rome), has been investigated in five fertile women in the follicular phase. The contents of a vial, corresponding to P 100 mg, was administered intravaginally by a syringe connected to an atraumatic cannula inserted in the vagina. While administering and for a further 10 minutes the woman remained in the recumbent position. Blood samples for P assay were drawn at the following times: 0, 15, 30, 45, 60, 120, 240, 360, 480 and 1440 minutes. Mean CMax was 5.08 +/- 1.66 ng/ml, and the difference between baseline and CMax values was statistically significant (p < 0.01). TMax resulted as 60 minutes (range 45-240 minutes). Mean serum levels lowered subsequently but resulted as still significantly higher than baseline (p < 0.05) after 1440 minutes. Mean AUC 0-1440 value was 4236.75 ng h/ml. Any local or systemic side-effects were noted. No evidence of vaginal irritation was observed in any women. On the basis of the present data it is possible to suggest that a twice daily administration schedule could ensure suitable P serum levels in fertile women.