Gelatin - Xanthan Gum As Wall Materials Research Complex Coacervation Prepared Microcapsules

In this paper, we have investigated the preparation process of microcapsules, basedon complex coacervation of the gelatin (G) and xanthan gum (XG) as wall material,model drug Ligusticum wallichii essential oil (LWO) as core material. With theencapsulation efficiency, antioxidant capacity and the release property as the indicatorsto study the influence of crosslinking temperature, pH and drug loading on the thenature of microcapsules.Infrared spectrum (FTIR) and Differential scanning calorimetry (DSC) analysisconfirmed the existence of gelatin-xanthan gum coacervates, which was formed byelectrostatic interaction between the cationic amino of gelatin and the anionic carboxylof xanthan gum, and conductance method obtained the best proportion for the complexcoacervation is1:1. High Performance Liquid Chromatography (HPLC) was establishedto measure the content of LWO.Central composite design/response surface method (CCD-RSM) was used tooptimize the preparation process of gelatin-xanthan gum microcapsules, encapsulationefficiency×30%+70%retention rate of core material as the effect value, combiningwith the single factor experimental results to conclude the best preparation technologyconditions: the concentration of gelatin and xanthan gum were20%and1%,respectively, drug loading capacity was39.23%, complex coacervation pH was3.0~3.5,50mL,5%glutaraldehyde was crosslinking1h at36℃, and then dryed under50℃.Scanning electron microscopy (SEM) observed that the prepared microcapsules showedthe rules of the spherical, surface density without holes, and there is slightly adhesionbetween the microcapsules. Laser particle size scanning results showed that themicrocapsules have a narrower particle size distribution, and uniform particle size (10~20μm), the average particle size was13.16±0.09μm. Accelerated testing showed thatthe antioxidant capacity of microcapsules have improved significantly. The averagecontent of micro capsule was36.20%, the encapsulation efficiency was90.99%. In this paper, gelatin-xanthan gum microcapsules were used to investigate thepharmacokinetics in vivo of rats. Experimental results showd that the absorption ofLWO in rats was conform to two compartment model, first-order absorption, the plasmaconcentration of LWO microcapsules was stabled, Cmaxreduced, Tmaxshifted rearward.In the relative bioavailability research, the bioavailability of LWO microcapsules was100.03%compared to the reference. There has good correlation between the in vitrorelease and in vivo absorption of LWO microcapsules.