This study aims designing a drug controlled release system having a zero-order kinetics without toxicity and ineffectiveness.
The polymer matrices of cross-linked p-(HEMA) and p-(AA) were used in the monolithic system. The release kinetics in p-(HEMA) was constant at various pH's, but in p-(AA) the release rate was low at pH2 and high at pH7. Although this monolithic system with p-(AA) can be used as a oral dose, it may be irrelevant in case that the drug was inserted in the hyperdermic layer. Thus the polymer matrices coated with bio-erodible material were designed.
The p-(HEMA-co-MMA) and p-(AA-co-MMA) were used as the polymer matrices and a p-(Lactide) as a coating material. The optimal release rate could be obtained by controlling the thickness of polymer matrices. Among the polymer matrices of 1.0, 1.5 and 2.3 mm thickness with coating of 10μ used in this experiment, the best release kinetics was shown in case of 1 mm thickness.
