Table 4.
Optimum combination of factors, predicted values, observed values, the residuals, and the prediction error percentage for the optimized formulations of CTZ-loaded polymethacrylate microspheres
| Factors | Optimum | |||
|---|---|---|---|---|
| ERL loading percentage (X1) | 21.11 | |||
| Emulsifier HLB (X2) | 9.6 | |||
| Talc percentage (X3) | 6.67 | |||
| Dispersed phase volume (X4) | 11.09 | |||
| Responses | Predicted | Observed | Residuala | Prediction errorb (%) |
| Particle size (Y1) | 136.2 | 142.3 | −6.1 | 4.48 |
| Angle of repose (Y2) | 35.29 | 33.25 | 2.04 | 5.78 |
| Production yield (Y3) | 83.52 | 84.43 | −0.91 | 1.09 |
| Encapsulation efficiency (Y4) | 86.70 | 87.10 | −0.4 | 0.46 |
| Loading capacity (Y5) | 14.32 | 13.79 | 0.53 | 3.70 |
| Initial release (Y6) | 30.00 | 28.78 | 1.22 | 4.07 |
| T85% (Y7) | 12.00 | 12.46 | −0.46 | 3.83 |
Notes:
a
Residual = predicted value – observed value.
b
Prediction error (%) = (observed value – predicted value)/predicted value ×100%.
Abbreviations: HLB, hydrophilic lipophilic balance; ERL, Eudragit RLPO; CTZ, cetirizine hydrochloride; T85%, time for 85% of drug release.