温敏凝胶中尼美舒利含量测定及稳定性研究

目的：建立温敏凝胶中尼美舒利的含量测定方法并考察其各种条件下的稳定性。方法：采用HPLC法,色谱柱为岛津Shim-Pack C18-ODS柱（150 mm×4.6 mm,5μm）,甲醇-水-冰醋酸（65∶35∶0.8）为流动相,流速为1.0 ml·min^-1;检测波长：299 nm;柱温：30℃,进样量为10μl。结果：凝胶中尼美舒利与各杂质及降解产物分离良好,在2.43-24.37μg·ml^-1范围内线性关系良好（r=0.999 8）,平均回收率为100.02%（RSD=1.12%,n=5）。最低检测限为0.098μg·ml^-1,最低定量限为0.25μg·ml^-1。强光照射试验、破坏性试验及长期稳定性试验结果表明,尼美舒利温敏凝胶长期稳定性良好,但在高温碱性、高温酸性、高温强氧化溶液和强光照条件下不稳定。结论：该方法可用于温敏凝胶中尼美舒利含量测定及稳定性研究,方法准确、可靠。制剂对热和光照的稳定性较差,宜阴凉避光保存。

Determination and Stability of Nimesulide in Thermo sensitive Hydrogels

Objective： To establish the method for determining nimesulide in thermo-sensitive hydrogels and study the stability of the preparation. Methods： An HPLC method was adopted with a Shim-Pack C18-ODS（ 150 mm × 4. 6 mm,5 μm） column,the mobile phase was composed of menthol-water-acetic acid（ 65∶ 35∶ 0. 8） with the flow rate of 1. 0 ml·min^-1 at 30℃,the detection wavelength was at 299 nm,and the injection volume was 10 μl. Results： The separation of nimesulide,impurities and degradation products was good. The linear range of nimesulide was 2. 43-24. 37 μg·ml^-1（ r = 0. 999 8）,the average recovery was 100. 02%（ RSD = 1. 12%,n= 5）. The lowest detectable limit and the lowest quantitation limit was 0. 098 μg·ml^-1and 0. 25 μg·ml^-1,respectively. The stability results of hard-light exposure,destructive testing and long-term testing showed that the preparation was basically stable at room temperature,while under high temperature with hard light,strong basicity,acidicity or oxidation solution,the preparation was unstable.Conclusion： The method is accurate and reliable in the determination and stability study of nimesulide thermo-sensitive hydrogels. The hydrogels should be stored in shady,cool and dark place.