Glomerular filtration rate (GFR) is usually determined by estimation of iothalamate (IOT) clearance. We have developed and validated an accurate and robust method for the analysis of IOT in human plasma and urine. The mobile phase consisted of methanol and 50 mM sodium phosphate (10:90; v/v). Flow rate was 1.2 mL/min on a C18 reverse phase column, Synergi-hydro (250 × 4.6 mm) 4 µm 80 Å, with an ultraviolet detector set to 254 nm. Acetonitrile was used for the deproteination and extraction of IOT from human plasma and urine. Precision and accuracy were within 15% for IOT in both plasma and urine. The recoveries of IOT in urine and plasma ranged between 93.14% and 114.74 and 96.04–118.38%, respectively. The linear range for urine and plasma assays were 25–1500 and 1–150 µg/mL respectively. The lower limits of detection were 0.5 µg/mL for both urine and plasma, with no interference from plasma and urine matices. This method has been fully validated according to FDA guidelines and the new HPLC assay has been applied to a new formulation of IOT (Conray™ 43), to calculate GFR in healthy volunteers. The new method is simple, less expensive and it would be instrumental in future clinical and pharmacokinetic studies of iothalamate in kidney patients.
展开▼
机译：肾小球滤过率（GFR）通常是通过估算碘草酸盐（IOT）清除率来确定的。我们已经开发并验证了用于分析人血浆和尿液中IOT的准确而可靠的方法。流动相由甲醇和50 mM磷酸钠（10：90； v / v）组成。在C18反相柱Synergi-hydro（250×4.6 mm）4 µm 80Å上，流速为1.2 mL / min，紫外检测器设置为254 nm。乙腈用于人血浆和尿液中IOT的脱蛋白和提取。在血浆和尿液中，物联网的精度和准确度均在15％以内。尿液和血浆中IOT的回收率分别在93.14％和114.74和96.04-118.38％之间。尿液和血浆检测的线性范围分别为25–1500和1–150 µg / mL。尿液和血浆的最低检测限均为0.5 µg / mL，不受血浆和尿液成分的干扰。此方法已根据FDA指南进行了充分验证，并且新的HPLC分析已应用于新的IOT制剂（Conray™43），以计算健康志愿者的GFR。该新方法简单，成本较低，并且将在将来对肾病患者中的碘草酸盐的临床和药代动力学研究中发挥作用。
展开▼
