The release of human immunoglobulin G (IgG) using ethylene-vinyl acetate co
polymer (EVAc) as a polymer carrier was studied by fabricating them into tw
o commercially available dosage forms. slab and microsphere. A first-order
flux decay model and two hierarchical models concerned with the mass transf
er coefficient on the slab surface were used to describe the mechanism of r
elease kinetics and the results compared. These models gave insight to some
of the important physical parameters of drug release such as the diffusion
coefficient, time constant of release, and initial flux. It was found that
the release mechanism varies with time, and hence no single model can be u
sed to predict the release profile for the entire period of study. A contro
lled release study by matrix coating was also done. The results obtained we
re utilized to examine the suitability of a particular dosage form (matrix
geometry) of IgG for clinical applications. The release data compared with
the standard methods of IgG therapy proves localized drug delivery to be a
major boon for immunodeficient patients.