Design and Optimization of Cationic Nanocapsules for Topical Delivery of Tretinoin: Application of the Box-Behnken Design, In Vitro Evaluation, and Ex Vivo Skin Deposition Study

Table 2

Formations of the three-level three-factor design for the formulation of encapsulated TTN.

Run	Factor levels in actual values
	: polymer amount (mg)	: drug amount (mg)	: oil amount (ml)
Midpoints
1	200	20	0.6
2	50	12.5	1
3	200	12.5	1
4	50	20	0.6
5	200	5	0.6
7	125	5	1
9	200	12.5	0.2
10	125	20	0.2
11	50	5	0.6
13	50	12.5	0.2
14	125	20	1
15	125	5	0.2
Center points
6	125	12.5	0.6
8	125	12.5	0.6
12	125	12.5	0.6