Law and mechanism of incorporating different insoluble drugs into mesoporous silica nanoparticles by dipping centrifugation method / 中草药

ABSTRACT

Objective: To investigate the relationship between drug concentration and drug loading efficiency and to explore mechanism of drug loading by incorporating different insoluble drugs into mesoporous silica nanoparticles with dipping centrifugation method. Methods: Mesoporous silica nanoparticles were characterized by transmission electron microscopy and nitrogen adsorption-desorption analysis. Silybin, puerarin, berberine, curcumin, and ferulic acid were used as model drugs and loaded into mesoporous silica nanoparticles using two technologies The volume of drug solution or drug amount was fixed respectively. The relationship between drug concentration and drug loading was analyzed. Paclitaxel, tanshinone IIA and tetrahydropalmatine were used to validate the law. Nanoparticles loaded silybin, puerarin, and ferulic acid with high drug loading efficiency were characterized by scan electron microscopy and DSC. Results: The average size of mesoporous silica nanoparticles was (220 ± 21) nm, with a specific surface area of 353.53 m2/g, pore size of 1.53 nm and pore volume of about 0.4 cm3/g. In the condition of a fixed mass ratio of drug to mesoporous silica nanoparticles, the drug loading efficiency was always linearly related to the drug concentration at the above preparation technology even if drug loading of different drugs were analyzed together. No obvious drug crystallines were observed in the surface of nanoparticles by scan electron microscopy. Melting peaks of silybin, puerarin and ferulic acid were all observed in DSC curves of mesoporous silica nanoparticles loaded drugs, but their heat absorption amounts per mg were all smaller than physical mixtures. Conclusion: The drug solution concentration was the key factor on drug loading efficiency of mesoporous silica nanoparticles by dipping centrifugation method and drugs existed in pores of mesoporous silica nanoparticles in crystalline and amorphous forms.