Including preparation of cinnamon oil by vinyl pyrrolidone/vinyl acetate copolymer VA64-Soluplus spray-dried microspheres / 中草药

ABSTRACT

Objective: To investigate the applicability of the spray-dried microspheres of vinyl pyrrolidone/vinyl acetate copolymer VA64-Soluplus for inclusion of cinnamon oil (CO) and compare with traditional inclusion technology of β-cyclodextrin. Methods: HPLC was used to determine the encapsulation rate of inclusion complex. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray powder diffraction (XRD) were used to characterize the inclusion complex; The dissolution and stability of the inclusion complex was investigated by in vitro release test and accelerated stability test; The pharmacokinetic and analgesic efficacy tests were used to examine the bioavailability and efficacy of the inclusion complex. Results: The encapsulation rate of microsphere inclusion complex and β-cyclodextrin inclusion complex was (98.38 ± 0.30)% and (86.51 ± 0.52)%, respectively. Observation of the inclusion complex under TEM showed a uniform spherical-like structure with uniform dispersion; Observation under SEM showed that the inclusion complex was spherical with a concave surface; The endothermic peak of volatile oil of cinnamon in DSC and the diffraction peak in XRD disappeared. The cinnamon volatile oil was dispersed in theinclusion complex in the form of non-aggregation; The cumulative release rates of cinnamon volatile oil, microsphere inclusion complex and β-cyclodextrin inclusion complex in in vitro dissolution experiments were 97.05%, 93.36% and 80.26%, respectively; Accelerated stability test at 60 ℃ showed that the loss rate of volatile oil of microsphere inclusion complex was significantly lower than that of cinnamon volatile oil and β-cyclodextrin inclusion complex; Pharmacokinetics showed that the AUC0-∞ of cinnamon essential oil, microsphere inclusion complex and β-cyclodextrin inclusion complex were basically the same; Pharmacodynamics showed that the analgesic rates of cinnamon volatile oil in the three groups were 53.0%, 47.5% and 21.1%, respectively. Conclusion: The stability of cinnamon volatile oil was enhanced by the combination of spray-dried microspheres of vinyl pyrrolidone/vinyl acetate copolymer VA64-Soluplus. The in vitro release, bioavailability and analgesic efficacy of microsphere were basically consistent with the volatile oil of cinnamon volatile oil, and it was superior to the inclusion compound of β-cyclodextrin. The vinyl pyrrolidone/vinyl acetate copolymer VA64-Soluplus microsphere inclusion compound had better water solubility. This study provides a new method for the inclusion of volatile oil.