Table 1 Variables of response surface design
From: Response surface method for optimization of prepared satranidazole powder layered pellets
Independent variables | Levels used | ||
|---|---|---|---|
Low (− 1) | Medium (0) | High (+ 1) | |
Design of experiment | |||
X1: Ratio of coating mixture % (Locust bean gum: Xanthan gum & Locust bean gum: Chitosan gum) | 1:2 or 33.3% | 1:1 or 50% | 2:1 or 66.7% |
X2: Coating level % | 10 | 20 | 30 |
Numerical optimization | |||
Dependent variables | Constraints Range | Goal | |
Y1: Drug release at 2 h. (%) | In the range | Minimize | |
Y2: Drug release at 6 h. (%) | In the range | Minimize | |
Y3: Drug release difference in presence & absence of colonic enzyme at 10 h. (%) | In the range | Maximize | |
Y4: Mean dissolution time | In the range | Minimize | |