Dear all
I need a clarification for the organic impurities test in the Monograph of (Amlodipine and Valsartan Tablets), USP2021
My understanding of the test is as follow:
1- The standard solution have 0.0003mg/ml strength of Amlodipine & Valsartan
2- The percentage of amlodipine related compound A is calculated on basis of (Sample Solution A, 0.1 mg/ml amlodipine) in comparison with the amlodipine related compound A peak in the standard solution.
3- The percentage of valsartan related degradation products other than valsartan related compound A are calculated on basis of (Sample Solution B, 0.16 mg/ml valsartan) in comparison with the valsartan peak in the standard solution. Please note that the monograph here talk about "valsartan related degradation products".
4- The 3rd part of this test trigger calculation of the percentage of each unspecified degradation product. I understand that this part of the test trigger the unspecified degradation products duo to Amlodipine only so we calculate them in comparison with the amlodipine peak in the standard solution at the same time the previous part of the test (point 3) has covered the valsartan related degradation products My problem is that the monograph is NOT clear in this and a statement is written as unspecified degradation product without further clarifications. SO please clarify this point for me, Regards