Table 1.

Independent variables and respective levels in the 3² CCFD for LCDP polymeric micelles preparation, model summary statistics of quadratic model, constrains for optimization and factors levels for optimized LCDP polymeric micelles formula and their predicted and observed values.

		Levels of variables
Factors (independent variables)		Low (−1)	Medium (0)	High (+1)		Optimized level
A: Pluronic to drug ratio a		10	30	50		45
B: P123 percentage (% w/w)		10	50	90		80
Responses	r2	Adjusted r2	Prediction r2	Constrains	Predicted	Observed	95% prediction interval
Y1: Entrapment efficiency (%)	0.9162	0.8900	0.8247 (0.8311) b	Maximize	100	99.23	81.06–123.26
Y2: Particle size (nm)	0.8650	0.8229	0.7200	Minimize	19.88	21.08	9.74–30.02
Y3: PDI	0.9053	0.8757	0.8257 (0.8366) b	Minimize	0.097	0.11	0.039–0.160

^aThe levels of variable (A) are 10:1, 30:1 and 50:1. Since the drug is always designated in the ratio as “1”, so the levels of variable (A) were written as 10, 30 and 50.

^bReduced model prediction r ².