The Initial Study Of RU486 Vaginal Gel

This study about the RU486 vaginal gel including three main parts: the preparetion of the RU486 vaginal gel, the assay and the study of stability of RU486 vaginal gel, and the pharmacokenics study of the RU486 animal researches.The purpose of this study is to elevant the drug concentration in target tissues by change the preparation. According to the property of vaginal drugs and the advancement of gel, carbomer was considered to be used as the basic materials of the prepartion. The prescription and prepairition condition were selected mainly by the physical-chemical property of RU486 and the research of the adjuvant. Finally the prescription was decided as follows: carbomer HY-III 940 acts as the basilaris substance, NaOH acts as pH regulator, absolute alcohol acts as wetting agent, glycerine acts as humidifier, substand B acts as stabilizer and solubilizing agent, ethylparabenum acts as the antiseptic. Three batches of sample products were prepaired under the selected conditions. The exterior and pH value were in line with the china pharmacopoeia.The quality and stability of the preparations determines the efficacy and safety of the drugs. HPLC is used to the assaying of the RU486 vaginal gel. The UV scan shows that RU486 ingredient absorption maximum at 302nm. Internal standard method used to assay the RU486 vaginal gel by HPLC indicated good lineal relationship between the drug mass concentration and the chromatography peak area in 2~500ng?ml-1 range(A=0.0042C+0.0546,R2=0.999). The recovery of three concentrations were as follow: 87.05%, 101.51% and 90.39%. The precision within-day and inter-day were all under 12.69%. Bsaed on the above researches, the accelerate experimentation was progressed according to the drug stability test in the chp 2005. Through the initial stability consideration test of three batches of sample products, the indication of RU486 vaginal gel was sensitive to the illumination. 78.21% drugs remained under the condition of room temperature and away from light.In the pharmacokenics study of animal experiments, rats and rabbits were choosed in different researches. The purpose was to evaluate the bioavailability of RU486 vaginal gel and RU486 suspension in rabbits, and compare the drug concentration in plasma with target tissue (uterus and ovaries) of RU486 gel in rats. The drug concentrations in the plasma and the tissues were determined by HPLC and the pharmacokinetic parameters and related bioavailability were obtained by using 3P97 software. The Bioavailability of RU486 gel was 89.31% of that in the suspension. The DTE of RU486 gel in uterus and ovaries were 3.570 and 12.99. These results indicated that compared with the RU486 suspension, the prepared vaginal gel raised the concentration and prolonge the resident time of the drug in the target tissues.Through the selection of prescription and prepairition condition and the advanced development, the prepairation of RU486 vaginal gel was convenient, reasonable and simple. Through the drug stability test, it is considered that the RU486 vaginal gel we prepaired were quality stable. Through the animal experiments, it is indicated that the RU486 vaginal gel elevanted the drug concentration in target tissues. This study set the base for further study of antiearly pregnancy drugs and contraseption vaginal medicine.