ABSTRACT
Objective To prepare the PLGA nanoparticles( NPs) loading tetrandrine, investigate in vitro drug release behavior. Methods Tetrandrine loaded PLGA NPs were prepared by the emulsion solvent diffusion method and the preparation process was optimized by changing the stabilizer concentration and emulsion energy. The drug loading and entrapment efficiency were studied to evaluate the drug-loading property.The influence of particles size and pH value of release media on drug release behavior was investigated. Results Nanoparticles in the mean size of(203.4±2.8)nm had spherical shape and showed negative surface charge.Drug loading and entrapment efficiency was(2.17±0.10)% and(67.88±4.27)%, respectively.Tet-PLGA NPs retarded drug release in vitro, the cumulative release percentage was increased with the particle size increasing and it in acidic release medium showed a higher drug release amount. Conclusion Tetrandrine loaded PLGA nanoparticles have good entrapment efficiency, uniform particle size and can retard drug release in vitro.
ABSTRACT
OBJECTIVE:To establish a HPLC method for determination of Vitamin B12 in compound vitamin capsules. METHODS:Compound vitamin capsules were determined by HPLC on a ODS column at room temperature.The mobile phase consisted of methyl alcohol and 0.05mol/L KH2PO4 buffer(22∶78,pH=6.4). The flow rate was 1.0ml/min,and the detection wave length was set at 360nm.The sample size was 20?l.RESULTS:The sample size of vitamin B12 presented a good linear relationship with peak area in the range of 10.20?g～204.00?g(r=0.9 999).The average recovery was 99.7%(RSD=1.18%).CONCLUSIONS:The present method is simple,convenient,and accurate for determination of vitamin B12 in compou_nd vitamin capsules,and it also has the advantage of preventing the interference from vitamin B6 and folic acid.