Zeta potential values of the I-optimal design experimental formulations.

Batch no.	Zeta potential (mV)	Batch no.	Zeta potential (mV)
1	−31.80	14	−34.17
2	−28.70	15	−30.33
3	−30.20	16	−28.37
4	−33.77	17	−33.37
5	−31.50	18	−32.00
6	−31.90	19	−33.87
7	−32.33	20	−32.10
8	−31.53	21	−26.40
9	−32.23	22	−26.87
10	−32.20	23	−26.57
11	−19.23	24	−28.90
12	−32.47	25	−26.97
13	−35.40	—	—