Development and Validation of Stability-Indicating RP-UPLC Method for Simultaneous Determination of Related Substances of S(−)Amlodipine and S(−)Metoprolol Succinate in Fixed Dose Combination Tablet Dosage Form

Table 4

Results of specificity test (peak purity criteria).

Peak name	Peak purity angle	Peak purity threshold	Purity criteria
S(−)Metoprolol	1.167	4.324	Pass
S(−)Amlodipine	0.042	0.533	Pass
Metoprolol Succinamide impurity	14.674	90.000	Pass
Amlodipine related compound-A	13.153	90.000	Pass