OBJECTIVE To investigate the stability of microencapsulated tetanus toxoid in the courses of preparation and release, and improve its stability by co encapsulation of additives.

• 目的研究破伤风类毒素聚乳酸微球中破伤风类毒素在制备过程和体内酸性环境中的稳定性及微球中附加剂的稳定作用。