用放射免疫法测定18-甲基炔诺酮和雌二醇的血药浓度,比较不同粒度的复方18-甲基炔诺酮注射剂的生物利用度。制剂Ⅱ微晶平均粒度小于5μm,给药初期药物释放快,d3达峰值。制剂Ⅰ微晶平均粒度为15μm,药物释放较制剂Ⅱ慢而平稳,最初数天血药浓度较制剂Ⅱ为低。而给药中、后期的血药浓度高于制剂Ⅱ.两制剂曲线下总面积无显著差异。雌二醇的血药浓度、达峰时间及血药浓度下降速度相似。 The plasma concentrations of 18-norgestrel and estradiol were measured by radioimmunoassay and the bioavailability of compound 18-norgestrel in different particle sizes was compared. The average particle size of preparation Ⅱ crystallites is less than 5μm, the initial drug release fast, d3 peak. Formulation I microcrystals average particle size of 15μm, drug release slower and more stable than the preparation Ⅱ, the first few days of plasma concentration than the preparation Ⅱ is low. The drug administration, the latter part of the plasma concentration higher than the preparation Ⅱ.The total area under the two formulations no significant difference. Estradiol plasma concentration, peak time and plasma concentration decreased similarly.