RP-HPLC Method for Determination of Several NSAIDs and Their Combination Drugs

Table 8

Full factorial design of experiments for robustness.

Exp.	Pattern	Flow rate (mL/min.)	pH	Buffer strength (mM)	Temperature (°C)
1	+−−−	1.2	3.05	10	30
2	−−−+	1	3.05	10	40
3	+−−+	1.2	3.05	10	40
4	−−+−	1	3.05	20	30
5	−++−	1	3.45	20	30
6	−+++	1	3.45	20	40
7	+−+−	1.2	3.05	20	30
8	−−++	1	3.05	20	40
9	+−++	1.2	3.05	20	40
10	++−−	1.2	3.45	10	30
11	−+−−	1	3.45	10	30
12	−−−−	1	3.05	10	30
13	++−+	1.2	3.45	10	40
14	++++	1.2	3.45	20	40
15	−+−+	1	3.45	10	40
16	+++−	1.2	3.45	20	30