ABSTRACT
AIM To prepare silymarin solid dispersions and to evaluate the dissolution rates of five constituents.METHODS Taking F68 and PVPk30 as a combined carrier,the solid dispersions were prepared by solvent fusion method.Then the effects of combined carrier ratio and drug-carrier ratio on dissolution rates of silybin,isosilybin,silydianin,silycristin and taxifolin were investigated.RESULTS The optimal conditions were determined to be 1 ∶ 3 for combined carrier ratio,and 1 ∶ 5 for drug-carrier ratio.These five constituents displayed much higher dissolution rates in solid dispersions than those in raw medicine and physical mixture (silymarin-carrier).CONCLUSION Solid dispersions can significantly increase the dissolution rates of effective components in silymarin.
ABSTRACT
The mesoporous silica nanoparticles (MSN) in different pore size and sirolimus (SRL) loaded self-microemulsifying drug delivery system (SMEDDS) were prepared. The results in morphology were collected by scanning electron microscope, transmission electron microscope, small-angle X-ray diffraction, and N2 adsorption-desorption. The results showed that the prepared MSN has ordered nanochannels with a pore size of 6.3, 8.1, 10.8 nm, respectively. The particle size of SRL-SMEDDS were measured by particle sizing system, which was 20.6±1.3 nm. The stirring method was developed to prepare SRL-SMEDDS-MSN. It was found that the optimal ratio of SRL-SMEDDS to MSN was 2:1, while the drug loading rate was near 0.83%, and the flow properties of SRL-SMEDDS-MSN were of good condition. The differential scanning calorimetry results proving a molecular or amorphous dispersed state of SRL in MSN while the suspension experiment has shown great reconstitution properties of SRL-SMEDDS-MSN. There is no significant influence on maximum drug release rate of different pore size of SRL-SMEDDS-MSN in 250 mL water within 2 h, while the results of the first 40 min have an obvious difference. Above all, MSN might provide a new strategy for the solidification of SMEDDS.