Rhynchophylline nanosuspensions sustained-release tablets: Preparation, optimization and release evaluation in vitro / 中草药

ABSTRACT

Objective: To prepare the rhynchophylline nanosuspensions and lyophilized powder, and study its sustained-release tablets. Methods: Rhynchophylline nanosuspensions were prepared by microprecipitation combined with high pressure homogenization method, and the particle size and zeta potential were determined. Scanning electron microscopy (SEM) was employed to observe the appearances of nanosuspensions. Nanosuspensions were prepared into lyophilized powder using lactose as freeze-dried protectors. HPMC (hydroxypropyl methyl cellulose) was used as hydrophilic matrix to prepare the sustained-release tablets. Single factor investigation and orthogonal experiments were employed to optimize the formulation of rhynchophylline nanosuspensions sustained-release tablets, and the model fitting was also been studied. Results: The particle size and zeta potential of rhynchophylline nanosuspensions were (153.7 ± 4.9) nm and (-18.54 ± 1.32) mV, respectively. The appearances of rhynchophylline nanosuspensions were spherical or nearly spherical. After orthogonal optimization, the cumulative release rate of rhynchophylline nanosuspensions sustained-release tablets was 92.53% in 12 h. The optimized formulation of hydrogel matrix sustained-release tablets was better accorded with Higuchi model ln(1-Mt/M∞)=0.286 0 t1/2-0.069 0 (r=0.992 4). The drug release from hydrogel matrix sustained-release tablets were controlled by diffusion and degradation. Conclusion: The obtained rhynchophylline nanosuspensions has small particle size. The prepared hydrogel matrix sustained-release tablets can control the release of rhynchophylline nanosuspensions in a slow characteristic.