Application of Central Composite Design-Based Response Surface Methodology in Optimization of the Preparation Process of Sanguinarine Chitosan Microspheres

We designed the present experiment to prepare the sanguinarine chitosan microspheres. First, using the chitosan as a carrier, we prepared sanguinarine microspheres by emulsion cross-linking method, and determined the drug loading and encapsulation efficiency of sanguinarine microspheres by high performance liquid chromatography (HPLC). Then, taking the particle size as the evaluation indicator, we optimized the preparation process by the central composite design-based response surface methodology (CCD-based RSM). Finally, we performed in vitro release test to examine the cumulative release of sanguinarine microspheres. As a result, the optimal process conditions: 0.06 g for sanguinarine dosage, 0.07 g for chitosan dosage, 2% for acetic acid concentration, 3:10 for volume ratio of oil to water, 40 degrees C for emulsion cross-linking temperature, 500 r/min for rotation speed, and 5% for emulsifier dosage. Under such conditions, the sanguinarine microspheres had round shape, the average particle size was (8.14 +/- 0.13) mu m, the particle size distribution was 2-20 mu m, the drug loading was (4.58 +/- 0.93)%, and the encapsulation efficiency was (54.64 +/- 0.39)%, the cumulative release within 24 h was (78.34 +/- 1.08)%. In conclusion, we successfully prepared the sanguinarine chitosan microspheres, and they have excellent morphology, suitable particle size, and good sustained-release effect.