Optimization of Ultrasound-Assisted Extraction of Morphine from Capsules of Papaver somniferum by Response Surface Methodology

Table 2

Values of the independent variables and their coded forms with their symbols employed in RSM for optimization of poppy straw through UAE.

Independent variables	Units	Symbols of the variables	Coded levels
			−1	0	1
Solvent/solid ratio	mL/500 mg	()	10	15	20
pH	pH	()	1	7	13
Extraction time	min	()	30	45	60
Extraction temp.	°C	()	30	40	50