Preparation technology of paeonol-β-cyclodextrin inclusion compound

Objective To set up the preparing technology of paeonol-β-cyclodextrin (β-CD) inclusion compound. Methods The inclusion conditions were optimized by using the orthogonal test for the compound formation of paeonol-β-CD, taking the rate of recovery and inclusion as the criteria. Three different including methods or equipments were adopted and compared with the documentary method. The effect of pH and HPMC on the inclusion of paeonol with β-CD was investigated. Results The inclusion rate and recovery rate were more than 80% and 75%, respectively following the optimized saturated solution method, i.e. resolving 1 part of paeonol in 6 parts of absolute alcohol, then slowly adding the solution into the saturated solution containing 10 parts of β-CD in 1/30 V/h at 45 ℃, keeping stirring until the inclusion compound formation. An A_L-type phase solubility curve was obtained. The difference of apparent stability constant is significant under different pH values and different HPMC contents. Conclusion The technology and procedure are relative simple and high efficient, which are applied for the industrialization. HPMC (0.05%) in pH 2.5 is shown to increase the inclusion of paeonol with β-CD.