Design,Fabrication And Application Of Mesoporous Silica/Metoprolol Complex Drug Loading System

With many advantages of uniform and adjustable pore diameter, neat channel arrangement, good biocompatibility, hydrothermal stability, the mesoporous silicahas been the research focus of inorganic materials,in recent years.In addition, mesoporous pore has huge specific surface area and pore volume,which can load in various medicine and easy to modifyinnerand outer surface chemical bonds as an ideal drug carrier material.Sodium alginate is natural polymer, which is hydrophilicity, non-toxic and no carcinogenicity and widely used in the field of food and medicine, especially in the pH sensitive slow-release drug fields.However, the traditional single effect on control release is not enough to satisfy the clinical application,so that precision control release systemis current research focus.Inorganic material and natural polymer composite materials used as drug carrier, can accumulatethe control release effect of single material to achieve goal of precision control release.This paper synthesized the MCM-41type mesoporous silica and amino modified to achieve the goal of control release, then,by the method of layer by layer self-assembly to coat the organic polymer on the drug loading particles to reach the function of pH sensitive.First of all, we treat the ethyl orthosilicate as inorganic silicon source, and hexadecyl trimethyl ammonium bromide as template agent to carry on the interface reaction.In alkaline conditions, the formation of silica skeleton of the honeycomb mesh structure of rules. We used reflux extraction and calcination method to get rid of template agent and to get mesoporous silica nanoparticle which has inorganic skeleton structure. And in the acidic conditions,were treated MSNs as raw materialand modified with silane coupling agent and polyetherimide to get chemical amino bonds.The impregnation method is used to loading tartrate metoprolol (MPT) by electrostatic interaction between the drug and the carrier. By layer by layer self-assembly methods, we coated sodium alginate and L-lysine on MSNs. Sodium alginate is a linear anionic brown algae polysaccharide, which is a common preparation material of microcapsule.Lysine is cationic polymers,which aminoelectrostatic interact with sodium alginate by G (ancient uronic acid) and M (mannose hyaluronic acid) on the molecular chain to form polymer coating layer so that we synthesized the inorganic organic composite control release drug system. The samples were tested in the simulated intestinal fluid and simulated gastric juice to research different functional groups and coating layer drug control release ability. The uniform pore structure of MCM-41 type mesoporous silica was synthesized successfully withamino grafted on the surface of silica (APMCM-41), which are characterized with FTIR, TEM, XPS, XRD and nitrogen adsorption and desorption. Results show that the carrier of amination of amino and carboxyl of metoprolol tartrate.combined by hydrogen bond and electrostatic interaction, and increased the metoprolol tartrate drug loading.The sodium alginate and L-lysine coating layers of by self-assembly method successfully and can block the drug release,which are characterized by TEM, ZETA potential and drug release test.But the drug release rate is lower,whichlead to the release effect did not show the pH sensitivitySecondly,the soluable drug release was tested used by different pore diameter KIT to research that the pore diameter impact on drug release rate and control release ability. Loading themetoprolol tartrate(MPT)by the impregnation method in the KIT channels,and then we coated sodium alginate and L-lysineon the outside of KIT-1 type mesoporous silicato form polymer coating by layer-by-layer self-assembly methods so that the inorganic/organic composite drug release system was synthesized. Results showed that the larger aperture KIT-1, the fasterdrug release rate. Successfulcoated sodium alginate and L-lysineon the surface material by self-assembly method, and in simulated gastric juice, the drug release rate is extremely low. Moreover,in simulated intestinal juice it played a control release act and pH sensitive drug release effect.