Process Optimization, Characterization, and Release Study In Vitro of an Intravenous Puerarin Lipid Micropheres Loaded with the Phospholipid Complex

Abstract

A new formulation of puerarin lipid microspheres with the puerarin–phospholipid complex was prepared. A central composite design approach was used for process optimization in order to obtain the acceptable puerarin–phospholipid complex. The physicochemical properties of the complex obtained by optimal parameters were investigated by Fourier transform infrared spectrophotometry (FTIS). The physicochemical characterizations of puerarin lipid microspheres was evaluated. The release study in vitro of puerarin was studied by using microdialysis and pressure ultrafiltration technology. Multiple linear regression analysis for process optimization revealed that the acceptable puerarin–phospholipid complex was obtained wherein the optimal values of X₁, X₂, and X₃ were 3, 60°C, and 3 hours, respectively. The FTIS studies of the complex demonstrated that puerarin and phospholipids were combined by non-covalent bonds, not form new compounds. The mean diameter and entrapment efficiency (%) were 171.35 and 87.94, respectively. The release of puerarin lipid microspheres could be evaluated by using microdialysis and ultrafiltration, but microdialysis seemed to be more suitable for the release study of puerarin lipid spheres. The drug release at three drug concentrations was initially rapid, but reached a plateau value within 30 minutes. Drug release of puerarin from the lipid microspheres occurred via burst release.

Keywords:

• Characterization
• lipid microspheres
• phospholipid complex
• process optimization

Notes

— Indicates the term was omitted in reduced model.

*Bias was calculated according to equation: bias/% = (predicted value-observed value)/predicted value × 100%.