Experimental design with independent variables and responses of the dependent variables for the formulations of melatonin-loaded NLC.

Run	A: drug to lipid ratio (% w/w)	B: liquid lipid to total lipid ratio (% w/w)	C: surfactant to lipid ratio (% w/w)	Y 1: mean particle size (nm)	Y 2: entrapment efficiency (%)
1	1	26	18	169.3	94
2	2.5	14	18	215.6	80.1
3	3.01	20	30	190.5	82.9
4	1.75	20	50.18	149.1	78.1
5	1.75	20	30	150	83.8
6	1.75	10	30	202.7	85.2
7	2.5	26	18	181.5	86.7
8	1	14	42	135.5	86.3
9	1.75	20	9.82	179.7	87
10	1	14	18	186.9	56.4
11	1	26	42	120.2	87.6
12	1.75	30	30	141.9	90
13	2.5	26	42	161.8	50.5
14	2.5	14	42	178.2	83.5
15	1.75	20	30	144.1	89.8
16	1.75	20	30	154	83.9
17	1.75	20	30	160.6	84.7
18	1.75	20	30	139.4	85.1
19	0.49	20	30	135	84.8
20	1.75	20	30	148	82