Production of Sterilizing Agents from Calendula officinalis Extracts Optimized by Response Surface Methodology

Table 1

Experimental ranges and levels of the independent variables.

Variables	Range and level
	−1	0	+1
Extraction temperature, °C ()	25	37.5	50
Solid/liquid ratio, g/200 mL ()	3.3	10.0	16.5
Extraction time, h ()	1	4	7