Stability-Indicating HPLC Determination of Gemcitabine in Pharmaceutical Formulations

Table 5

Factorial design data for robustness of chromatographic separation.

(a)

Selected parameters and their variations	−1 (lower limit)	+1 (upper limit)
Acetonitrile in mobile phase (%) ()	8	12
Final pH of the mobile phase ()	6.8	7.2
Column oven temperature (°C) ()	20	30
Flow rate (mL/min) ()	0.8	1.2

(b)

Exp. number	Run order						-D	-I
1	6	8	6.8	20	0.8	14.01	1.12	1.2
2	11	12	6.8	20	0.8	13.1	1.11	1.19
3	5	8	7.2	20	0.8	14.1	1.09	1.18
4	13	12	7.2	20	0.8	13.2	1.08	1.1
5	1	8	6.8	30	0.8	14.3	1.09	1.11
6	7	12	6.8	30	0.8	10.2	1.09	1.08
7	10	8	7.2	30	0.8	14.5	1.11	1.15
8	15	12	7.2	30	0.8	11.85	1.1	1.08
9	12	8	6.8	20	1.2	13.51	1.13	1.11
10	14	12	6.8	20	1.2	10.21	1.05	1.07
11	9	8	7.2	20	1.2	14.41	1.09	1.12
12	2	12	7.2	20	1.2	10.05	1.06	1.07
13	8	8	6.8	30	1.2	13.25	1.12	1.1
14	4	12	6.8	30	1.2	10.15	1.04	1.07
15	3	8	7.2	30	1.2	14.12	1.1	1.11
16	16	12	7.2	30	1.2	10.15	1.05	1.05

: resolution factor, -D: tailing factor for drug, and -I: tailing factor for IS.