Table 5.

Central composite design results

	Factors		Entrapment efficiency (%)	Drug-loading coefficient (%)	Particle size	PDI
	X1 (mg)	X2 (mL)
1	3.6	13.5	63.3	18.5	278.3	0.786
2	3.6	6.5	72.4	20.6	300.2	0.873
3	1.4	13.5	68.5	8.8	180.3	0.269
4	1.4	6.5	90.5	11.2	198.4	0.312
5	4	12.5	65.4	20.7	330.2	0.887
6	1	12.5	61.2	5.7	176.5	0.323
7	2.5	15	65.7	14.1	189.7	0.348
8	2.5	5	76.8	16.1	210.2	0.563
9	2.5	12.5	81.7	16.9	192.3	0.276
10	2.5	12.5	83.2	17.2	196.4	0.254
11	2.5	12.5	82.3	17.0	185.3	0.313
12	2.5	12.5	80.2	16.7	186.4	0.321
13	2.5	12.5	83.9	17.3	198.2	0.264

Notes: X₁, the amount of harmine; X₂, the hydration volume.

Abbreviation: PDI, polydispersity index.