Abstract: A release model for diffusion-controlled monolithic matrix coated with outer membrane
system is proposed and solved by using the refined double integral method. The calculated
results are in satisfactory agreement with the experimental release data. The present model
can be well used to describe the release process for all cd/cs values. In addition, the
release effects of the monolithic matrix coated with outer membrane system are discussed
theoretically.

Key words: controlled release, diffusion, mercaptopurinum, monolithic matrix, outer membrane

摘要： A release model for diffusion-controlled monolithic matrix coated with outer membrane
system is proposed and solved by using the refined double integral method. The calculated
results are in satisfactory agreement with the experimental release data. The present model
can be well used to describe the release process for all cd/cs values. In addition, the
release effects of the monolithic matrix coated with outer membrane system are discussed
theoretically.

关键词: controlled release;diffusion;mercaptopurinum;monolithic matrix;outer membrane