Ji Allena J, Saunders James P, Amorusi Peter, Wadgaonkar Nandan D, O'Leary Kenneth, Leal Mauricio, Dukart Gary, Marshall Bonnie, Fluhler Eric N
Bioanalytical R & D, Wyeth Research, 401 North Middletown Road, Pearl River, NY 10965, USA.
J Pharm Biomed Anal. 2008 Nov 4;48(3):866-75. doi: 10.1016/j.jpba.2008.06.020. Epub 2008 Jul 6.
Tigecycline (Tygacil,Wyeth) is a first-in-class, broad spectrum antibiotic with activity against multiple-resistant organisms. In order to address the unexpectedly low tigecycline concentrations in human bone samples analyzed using a LC/MS/MS method developed elsewhere, we have developed and validated a new and sensitive human bone assay for the quantitation of tigecycline using LC/MS/MS. The new method utilizes the addition of a stabilizing agent to the human bone sample, homogenization of human bone in a strong acidic-methanol extraction solvent, centrifugation of the bone suspension, separation by liquid chromatography, and detection of tigecycline by mass spectrometry. Linearity was demonstrated over the concentration range from 50 to 20,000 ng/g using a 0.1g human bone sample. The intra- and inter-day accuracy of the assay was within 100+/-15%, and the corresponding precision (CV) was <15%. The stability of tigecycline was evaluated and shown to be acceptable under the assay conditions. The extraction recovery of tigecycline with the current method was 79% when using radio-labeled rat bone samples as a substitute for human bone samples. Twenty-four human bone samples collected previously from volunteers without infections who had elective orthopedic surgery after receiving a single dose of tigecycline were re-analyzed using the current validated method. Tigecycline concentrations in these samples ranged from 238 to 794 ng/g with a mean value 9 times higher than the mean concentration previously reported. The data demonstrated that the current method has significantly higher extraction efficiency than the previously reported method.
替加环素（泰阁，惠氏公司）是首个新型的广谱抗生素，对多重耐药菌具有活性。为了解决使用其他地方开发的液相色谱/串联质谱法分析人体骨样本时替加环素浓度意外偏低的问题，我们开发并验证了一种新的、灵敏的液相色谱/串联质谱法用于定量人体骨样本中的替加环素。新方法是在人体骨样本中添加一种稳定剂，将人体骨在强酸性甲醇萃取溶剂中匀浆，对骨悬液进行离心，通过液相色谱分离，并通过质谱检测替加环素。使用0.1g人体骨样本，在50至20,000 ng/g的浓度范围内证明了线性关系。该测定法的日内和日间准确度在100±15%以内，相应的精密度（CV）<15%。评估了替加环素在测定条件下的稳定性，结果表明是可接受的。当使用放射性标记的大鼠骨样本替代人体骨样本时，当前方法对替加环素的提取回收率为79%。使用当前验证的方法对之前从接受单剂量替加环素后进行择期骨科手术的无感染志愿者收集的24份人体骨样本进行了重新分析。这些样本中的替加环素浓度范围为238至794 ng/g，平均值比之前报道的平均浓度高9倍。数据表明，当前方法的提取效率明显高于之前报道的方法。
