Table 1.

Central composite design for the optimization of PF-NP preparation

Run	Coded variable		Decoded variable		Experimental points
	X1	X2	PGA1	Fucoidan2	Particle size (Y1)	Zeta potential (Y2)	Polydispersity (Y3)	Derived count rate (Y4)
1	1	1	1.35	0.18	407 ± 27	22.1 ± 1.2	0.258 ± 0.020	198,723 ± 32,490
2	1	−1	1.35	0.06	373 ± 18	21.7 ± 1.7	0.176 ± 0.022	303,170 ± 11,008
3	−1	1	0.85	0.18	325 ± 21	17.3 ± 1.4	0.072 ± 0.020	470,931 ± 42,474
4	−1	−1	0.85	0.06	540 ± 50	15.8 ± 1.7	0.044 ± 0.036	168,700 ± 20,114
5	0	0	1.10	0.12	306 ± 8	18.9 ± 0.9	0.109 ± 0.012	443,870 ± 2,514
6	0	0	1.10	0.12	302 ± 12	18.9 ± 0.8	0.100 ± 0.018	456,063 ± 31,375
7	2	0	1.60	0.12	483 ± 32	23.3 ± 1.1	0.292 ± 0.026	183,600 ± 27,849
8	−2	0	0.60	0.12	774 ± 46	12.4 ± 0.7	0.062 ± 0.019	79,994 ± 6,695
9	0	2	1.10	0.24	310 ± 9	19.2 ± 1.6	0.142 ± 0.017	450,611 ± 23,143
10	0	−2	1.10	0.00	326 ± 15	19.8 ± 2.0	0.099 ± 0.025	299,159 ± 25,807

¹⁾Concentration of polyglutamic acid (mg/mL).

²⁾Concentration of fucoidan (mg/mL).