Application of HPLC with ELSD Detection for the Assessment of Azelaic Acid Impurities in Liposomal Formulation

Table 2

Results of the evaluation of the precision of the system.

Content [%]
No. of the sample	I5; 𝑅𝑡=24.9′	I6; 𝑅𝑡=29.8′	U2; 𝑅𝑡=23.1′	U5; 𝑅𝑡=26.8′	U6; 𝑅𝑡=31.3′
1	0.03	0.11	0.09	0.75	0.16
2	0.03	0.09	0.09	0.72	0.13
3	0.03	0.13	0.07	1.01	0.14
4	0.03	0.13	0.07	1.08	0.14
5	0.03	0.12	0.06	0.58	0.13
6	0.02	0.10	0.07	0.54	0.11
7	0.03	0.11	0.07	0.63	0.11
8	0.04	0.13	0.08	0.97	0.14
𝑋	0.03	0.12	0.08	3.28	0.15
SD	0.03	0.12	0.08	1.26	0.14
RSD	0.005	0.02	0.01	1.05	0.02

I5 and I6: identified impurities; U2, U5, U6: unidentified impurities; 𝑅_𝑡: retention time; 𝑋: average; SD: standard deviation; and RSD: relative standard deviation.