Oldfield N, Chang D, Garland W, Town C
Department of Drug Metabolism, Hoffmann-La Roche, Inc., Nutley, NJ 07110.
J Chromatogr. 1987 Nov 27;422:135-43. doi: 10.1016/0378-4347(87)80446-2.
A method is described for quantifying ceftetrame, the acid metabolite of methylene (6R,7R)-7-[(Z)-2-(2-amino-4-thiazolyl)-2-(methoxyimino)acetamido]-3- [(5-methyl-2H-tetrazol-2-yl)-methyl]-8-oxo-5-thia-1-azabicyclo[4.2 .0]oct-2-ene-2-carboxylate pivalate, an orally active cephalosporin. Sodium benzylpenicillin is added to the plasma as the reference standard. The compounds are extracted from plasma or urine using a Bond Elut phenyl column. An aliquot of the methanol eluate is analyzed by high-performance liquid chromatography using a Waters Nova-Pak phenyl column and a UV detector set to 225 nm. The ratios of the peak heights for ceftetrame and sodium benzylpenicillin are calculated and converted to concentrations of analyte with calibration curves that are generated from the analysis of analyte-free plasma or urine fortified with various amounts of ceftetrame and a fixed amount of sodium benzylpenicillin. For plasma, the limit of quantitation for the assay is 0.48 microgram/ml and the inter-assay precision (relative standard deviation) is 9.3%. For urine, the limit of quantitation for the assay is 19.1 micrograms/ml, and the inter-assay precision is 4.9%.
描述了一种用于定量测定头孢替唑钠的方法，头孢替唑钠是亚甲基（6R，7R）-7-[(Z)-2-(2-氨基-4-噻唑基)-2-(甲氧基亚氨基)乙酰胺基]-3-[(5-甲基-2H-四氮唑-2-基)甲基]-8-氧代-5-硫杂-1-氮杂双环[4.2.0]辛-2-烯-2-羧酸酯新戊酸酯的酸性代谢物，一种口服活性头孢菌素。将苄青霉素钠作为参比标准加入血浆中。使用Bond Elut苯基柱从血浆或尿液中提取这些化合物。取甲醇洗脱液的一份等分试样，用高效液相色谱法分析，使用Waters Nova-Pak苯基柱和设定为225 nm的紫外检测器。计算头孢替唑钠和苄青霉素钠的峰高比，并通过校准曲线将其转换为分析物浓度，校准曲线由对添加了不同量头孢替唑钠和固定量苄青霉素钠的无分析物血浆或尿液进行分析生成。对于血浆，该测定法的定量限为0.48微克/毫升，批间精密度（相对标准偏差）为9.3%。对于尿液，该测定法的定量限为19.1微克/毫升，批间精密度为4.9%。
