Table 1.

Central composite design results (mean ± SD, n = 3)

No.	Levels of variables			Actual values of variables			Observed
	X1	X2	X3	%P188 (w/v)	%P407 (w/v)	%HPMC (w/v)	T (°C)
1	-1	-1	-1	2.11	18.85	0.25	42.03 ± 0.25
2	+1	-1	-1	7.89	18.85	0.25	49.73 ± 0.30
3	-1	+1	-1	2.11	21.15	0.25	32.17 ± 0.28
4	+1	+1	-1	7.89	21.15	0.25	46.2 ± 0.35
5	-1	-1	+1	2.11	18.85	0.95	43.43 ± 0.35
6	+1	-1	+1	7.89	18.85	0.95	48.16±0.28
7	-1	+1	+1	2.11	21.15	0.95	30.2 ± 0.17
8	+1	+1	+1	7.89	21.15	0.95	43.2 ± 0.26
9	-1.732	0	0	0	20	0.6	28.96 ± 0.25
10	+1.732	0	0	10	20	0.6	50.2 ± 0.20
11	0	-1.732	0	5	18	0.6	48.00 ± 0.31
12	0	+1.732	0	5	22	0.6	37.73 ± 0.25
13	0	0	-1.732	5	20	0	43.5 ± 0.20
14	0	0	+1.732	5	20	1.2	42.47 ± 0.25
15	0	0	0	5	20	0.6	43.2 ± 0.17
16	0	0	0	5	20	0.6	43.3 ± 0.20
17	0	0	0	5	20	0.6	43.17 ± 0.28
18	0	0	0	5	20	0.6	43.5 ± 0.26
19	0	0	0	5	20	0.6	43.5 ± 0.10
20	0	0	0	5	20	0.6	43.23 ± 0.20

Note: P188, Poloxamer 188; P407, Poloxamer 407; HPMC, Hydroxypropyl methylcellulose.