Diabetic retinopathy is a major cause of vision loss in adults. Novel eye-drop formulations of candesartan and irbesartan are being developed for its cure or treatment. To support a preclinical trial in rabbits, it was critical to develop and validate a new LC-MS/MS method for simultaneous quantification of candesartan and irbesartan in rabbit eye tissues (cornea, aqueous humor, vitreous body and retina/choroid). Eye tissue samples were first homogenized in H2 O-diluted rabbit plasma. The candesartan and irbesartan in the supernatants together with their respective internal standards (candesartan-d4 and irbesartan-d4 ) were extracted by solid-phase extraction. The extracted samples were injected onto a C18 column for gradient separation. The MS detection was in the positive electrospray ionization mode using the multiple reaction monitoring transitions of m/z 441 → 263, 445 → 267, 429 → 207, and 433 → 211 for candesartan, candesartan-d4 , irbesartan and irbesartan-d4 , respectively. For the validated concentration ranges (2-2000 and 5-5000 ng/g for candesartan and irbesartan, respectively), the within-run and between-run accuracies (% bias) were within the range of -8.0-10.0. The percentage CV ranged from 0.6 to 7.3. There was no significant matrix interference nor matrix effect from different eye tissues and different rabbits. The validated method was successfully used in the Good Laboratory Practice (GLP) study of rabbits.

中文翻译：

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液相色谱-串联质谱法同时定量兔眼组织中的坎地沙坦和厄贝沙坦。

糖尿病性视网膜病是成年人视力丧失的主要原因。坎地沙坦和厄贝沙坦的新型滴眼剂配方正在研发中，以用于治疗或治疗。为支持兔的临床前试验，至关重要的是开发和验证一种新的LC-MS / MS方法，用于同时定量兔眼组织（角膜，房水，玻璃体和视网膜/脉络膜）中的坎地沙坦和厄贝沙坦。首先将眼组织样品在H2 O稀释的兔血浆中匀浆。通过固相萃取法提取上清液中的坎地沙坦和厄贝沙坦及其各自的内标（坎地沙坦-d4和厄贝沙坦-d4）。将提取的样品注入C18色谱柱进行梯度分离。MS检测是在正电喷雾电离模式下，对坎地沙坦，candesartan-d4，irbesartan和irbesartan-d4分别使用m / z 441→263、445→267、429→207和433→211的多个反应监测转换。对于验证的浓度范围（坎地沙坦和厄贝沙坦分别为2-2000和5-5000 ng / g），批内和批间准确度（偏差百分比）在-8.0-10.0范围内。CV百分比范围从0.6到7.3。不同眼组织和不同兔子均无明显基质干扰或基质效应。经验证的方法已成功用于兔子的良好实验室规范（GLP）研究中。对于验证的浓度范围（坎地沙坦和厄贝沙坦分别为2-2000和5-5000 ng / g），批内和批间准确度（偏差百分比）在-8.0-10.0范围内。CV百分比范围从0.6到7.3。不同眼组织和不同兔子均无明显基质干扰或基质效应。经验证的方法已成功用于兔子的良好实验室规范（GLP）研究中。对于验证的浓度范围（坎地沙坦和厄贝沙坦分别为2-2000和5-5000 ng / g），批内和批间准确度（偏差百分比）在-8.0-10.0范围内。CV百分比范围从0.6到7.3。不同眼组织和不同兔子均无明显基质干扰或基质效应。经验证的方法已成功用于兔子的良好实验室规范（GLP）研究中。