Preparation and application of cross-linked PVA microspheres with narrow particle size distribution by suspension polymerization using uniform porous tube

PVA microspheres have high strength and plenty of hydroxyl groups, which has obvious advantages in a hydrophilic environment. However, the preparation of uniform larger size PVA microspheres with a diameter bigger than 100 mu m is still extremely tough. Membrane emulsification is an excellent method to obtain a monodisperse microsphere, but the diameter is generally several microns to tens of microns. Inspired by the membrane emulsification method, in order to get over 100 mu m microspheres, on titanium tube uniform micro pores were produced by laser drilling. Uniform monomer droplets with vinyl acetate and cross-link agent 1,4butanediol divinyl ether (BDVE) were all the time obtained by a simple device applying the tube as a membrane. After polymerization, cross-linked PVAc microspheres underwent alcoholysis. Cross-linked PVA micro spheres ultimately were obtained. PVA microspheres' sizes varied from 120 mu m to 800 mu m with a maximum coefficient of variation of less than 13% were prepared by changing different pore size tubes. Cross-linked PVA microspheres have a good spheroidal shape, solvent resistance and good strength. Through the amination reaction, some hydroxyl groups were connected with amino groups, which was more conducive to the loading of drug molecules such as indomethacin.

Automated summary

The study focuses on preparing cross-linked PVA microspheres with a diameter over 100 µm using membrane emulsification method, which could obtain PVA microspheres with different sizes by changing the tube pore size, showing good shape and strength, and more conducive to loading drug molecules through amination reaction.