Determination Of Progesterone And Its Main Metabolite In Rats By HPLC And Study On The Progesterone Pellicles' Local Absorb

Progesterone is a natural progestogen. It is mainly produced by corpus luteum during the luteal phase, also can be produced by placenta and adrenal gland. It is indispensable to pregnancy. It has extensive application in clinical practice, such as inadequate luteal phase, assisted reproduction, premenstrual syndrome, hormone replacement therapy, etc. Recently, more and more researchers give their attention to the transvaginal administration of progesterone. The vaginal route offers some important advantages over other methods: it is convenient and acceptable for many patients, is not painful, does not require any special equipment, and rarely produces allergic reactions, systemic levels are low. This thesis firstly developed a HPLC method to simultaneous determination of progesterone and 20α-hydroxy-4-pregnen -3-one ( 20α-OHP ) in plasma and uterus of rats, then carried out a study on pharmacokinetics of progesterone in rats plasma and uterus after administrated progesterone pellicles by vaginal route and progesterone injection by intramuscular route, and at last compared the pharmacokinetics parameters of administration vaginally and intramuscularly.Plasma and uterus samples were prepared by liquid-liquid extraction and separated through ODS column. The mobile phase consists of acetonitrile and water (60 : 40, adjusted to pH 4.0 with phosphoric acid). The detector was set at 240 run. Norgestrel was used as the internal standard. Progesterone, 20α-OHP and internalstandard were well separated under this chromatographic condition. The method had well linear, r exceed 0.9997. The limit of quantitation of progesterone was 6 ngL~ 1 in plasma and 13 ng-g"1 in uterus homogenate. The mean recoveries of progesterone and 20a-OHP in plasma were 98.6% and 96.5%, in uterus homogenate were 95.0% and 101.5% respectively. The HPLC method of determination of progesterone and its metabolite simultaneously was not reported at home and abroad.The pharmacokinetics were investigated in 50 ovariectomized female rats each formulation. The results showed that after administrated by the two route, progesterone in plasma and uterus could be fitted to an one-compartment model. After administrated progesterone pellicles, the maximal plasma concentration (Cmax) was 1/5 and the area under curve (AUC(o-48h)) in plasma was 1/6, comparing to after administrated progesterone injection. But the Cmax and AUC(o-48h) of the two formulation in uterus were corresponded. This result proved that the progesterone pellicles could be locally absorbed, and had low systemic levels.Progesterone could metabolized to 20a-OHP in rats plasma and uterus after administration vaginally and intramuscularly. 20a-OHP in rats plasma could be fitted to a two-compartment model after administration intramuscularly.The experimentation above provided the characters of local absorb after progesterone pellicles administrated vaginally, and provided important references to the clinical application of the progesterone pellicles.