Table 1. Variables and their actual and coded values selected to perform the optimization.

Level	Low	Medium	High
Coded values	-1	0	+1
X1a	20%	30%	40%
X2a	5%	10%	15%
X3a	2 minutes	5 minutes	8 minutes

^a X1 is % of lipid, X2 is % of surfactant, and X3 is sonication time