目的 研制适宜儿童用药的地西泮直肠输入制剂(diazepam rectal delivery system)——直肠灌注剂，并建立其含量测定方法。方法 以适宜复合溶媒系统和工艺溶解主药，通过处方筛选和考察制剂在室温、高温（40℃，60℃）、强光等条件下的稳定性进而确定处方。用高效液相-紫外色谱法测定制剂的含量，并对含量测定进行了方法学研究。色谱条件为：流动相为甲醇-水，检测波长254 nm，以萘为内标物。结果 确定的丙二醇-乙醇复合溶媒对地西泮直肠灌注剂起到较好的溶解和助稳定作用，建立的高效液相-紫外色谱法，在25～350 mg·L^-1范围内线性良好（r=0.999 98），回收率为98.97%～100.45%，日内及日间相对标准偏差平均为1.76%和0.65%。结论 研究的儿科用地西泮直肠灌注剂稳定、方便、可行，建立的高效液相色谱方法，测定含量简便、精确。

OBJECTIVE To develop a new clysma preparation of diazepam rectal delivery system for pediatrics and to determine the content of diazepam in the preparation.METHODS By selection of the formula and the process, diazepam was dissolved in the co-solvent system. The stability of diazepam rectal clysma was investigated under the conditions of room temperature, high temperature(40℃,60℃), strong light(4 500 lux) etc..The content of diazepam in the rectal clysma was determined by a reversed phase high performance liquid chromatography.The mobile phase was consisted of methanol and water (70∶30).The ultraviolet detection wavelength was at 254 nm and the naphthalene was used as the internal standard.RESULTS The propylene glycol co-solvent played a key role for stabilization.The standard curves were obtained with a liner range of 25～350 mg·L^-1 (r=0.999 98,n=5).The recovery was from 98.97% to 100.45%, the average relative standard deviation of intra- and inter-day were 1.76% and 0.65%,respectively.CONCLUSION The preparation of diazepam rectal clysma was stable,convenient and feasible. The established HPLC-UV method can be used for daily determination of diazepam rectal clysma and other preparations of the diazepam.